SDMS DocID 460472

Prepared by

Richard Hebert Site Manager EG Jordan Co

bullltbullraquo

201758

ri poppj-ds Center

MUOTTX

EPA WORK ASSIGNMENT NUMBER 103-1L27

EPA CONTRACT NUMBER 68-01-7250

EBASCO SERVICES INCORPORATED

FINAL REPORT WETLANDS ASSESSMENT

CANNONS ENGINEERING CORPORATION SITE

BRIDGEWATER MASSACHUSETTS

APRIL 1987

Approved by

- laquoissell H Boyd Jr PE Regional Manager Region I Ebasco Services Incorporated

NOTICE

The information in this document has been funded by the United States Environmental Protection Agency (EPA) under REM III Contract No 68-01-7250 to Ebasco Services Inc (EBASCO) This document has been formally released by Ebasco to the EPA This document does not represent however the EPAs position on policy and has not been formally released by the EPA

TABLE OF CONTENTS

SECTION TITLE PAGE NO

10 INTRODUCTION 1 11 Background 1 12 Purpose 2 13 Approach 2

20 WETLAND IDENTIFICATION AND CHARACTERIZATION 4 21 Identification and Location of Wetland

Areas 4 22 Biological Characterization 8

221 Terrestrial Organisms 8 222 Aquatic Organisms 10 223 Threatened and Endangered

o p 6 C X 6 S bull bull bull bull bull bull bull bull bull bull bull bull bull XU 23 Hydrogeologic Characterization 11

231 Surface Hydrology 11 232 Groundwater Hydrology 12 233 Geology 12 234 100-Year Flood Potential 12

30 WETLAND FUNCTIONAL ATTRIBUTES 15 3 1 Hydrologic Functions 15

311 Groundwater Recharge and Discharge 15

312 Flood Storage and Desynchronization 16

32 Habitat Functions 16 321 Wildlife Habitat 16 322 Aquatic Habitat 16

33 Water Quality Functions 17 331 Sediment Trapping 17 332 Nutrient Retention and Removal 17 333 Contaminant Retention and

Removal 17 334 Oxygen Production 18

34 Socioeconomic Functions 18 35 Summary of Wetland Functional

Attributes 18

- 1 shy

TABLE OF CONTENTS (continued)

SECTION TITLE PAGE NO

40 EFFECTS OF CONTAMINATION 19 41 Extent of Contamination 19

411 Sediments 19 412 Surface Water 22

42 Impacts to Wetlands 22 421 Ecotoxicity Assessment 22 422 Future Impacts 28

50 WETLANDS PROTECTION REGULATIONS 29

60 SUMMARY AND CONCLUSIONS 30

APPENDIX A - REFERENCES APPENDIX B - HAZARDOUS SUBSTANCE LIST AND CONTRACT

REQUIRED DETECTION LIMITS

- 1 1 shy

LIST OF TABLES

TABLE TITLE PAGE NO

2-1 Plant Species Observed in the Wooded Swamp and Wet Area on September 11 1985 and Relative Abundance Estimates 9

4-1 Organic Contaminants Detected in Soils Sediments in the Wet Area 20

4-2 Organic Contaminants Detected in Soils Sediments in the Drainage Ditch Drainage Canal and Wooded Swamp 21

4-3 Organic Contaminants Detected in Surface Waters 23

4-4 Ecotoxicity Test Results and Ambient Water Quality Criteria for Selected Contaminants Detected in Wetlands at the CEC Site 25

4-5 Maximum Levels of Inorganic Constituents in Surface Waters and Ambient Water Quality Criteria 27

I bull bull

- 1 1 1 shy

LIST OF FIGURES

FIGURE TITLE PAGE NO

2-1 Site Location Map 5

2-2 National Wetlands Inventory Map 6

2-3 Location of Wetland Areas and Sampling Locations 7

2-4 Location of the 100-year Flood Plain 13

-IVshy

10 INTRODUCTION

11 BACKGROUND

The Cannons Engineering Corporation (CEC) site inMassachusetts was a waste handling operationchemical wastes in tanks and drums for on-siteBased on verbal communication with the Bridgewater

Bridg which incine fire

ewater stored ration chief

it is known that the incinerator was used frequently for a period of time in the mid-1970s between 1974 and 1980 CECs hazardous waste handling license was revoked by the Massachusetts Executive Office of Environmental Affairs (EOEA) in 1980 because of alleged reporting and waste handling violations CEC attempted to comply with the conditions placed on their activities by the court but was forced to cease operations at the site in November 1980 due to financial and legal difficulties Approximately 155000 gallons of sludge and liquid wastes were left at the site in drums and bulk storage at the time of closure Between 1980 and 1982 site inspections sampling and analysis activities were performed by the Massachusetts Department of Environmental Quality Engineering (DEQE) and a US Environmental Protection Agency (EPA) Field Investigation Team (FIT) to determine the presence of chemical contamination at the site In December 1982 the site was included in the EPA Superfund program The waste material stored on-site was removed by Jetline Services from October to December 1982

In October 1983 EC Jordan Co (Jordan) was engaged by NUS Corporation (NUS) to conduct a Remedial Investigation and Feasibility Study (RIFS) at the site NUS acted as the EPA Zone 1 Contractor during the period from 1982 to 1986 for Performance of Remedial Response Activities at Uncontrolled Hazardous Substance Facilities A draft RI report based on the findings of the original scope of work was submitted to the EPA in June 1985 A supplemental investigation was completed at the site in August 1985 and the results were incorporated into a draft RI report of June 1986 In August 1986 Ebasco Services Inc (Ebasco) became the new contractor under the REM III Program A second draft RI report was prepared in November 1986 Investigations conducted at the site have determined that chemical contamination includes volatile organics semivolatile organics pesticides PCBs and metals

In April 1986 Jordan was engaged by NUS to prepare an Endangerment Assessment (EA) of the site A draft EA report was prepared for Ebasco under the REM III Program in December 1986

The ecological systems on and adjacent to the site have been described in a baseline investigation that was prepared for Jordan by Normandeau Associates Inc in October 1985 In

-1shy

April 1986 NUS engaged Jordan to revise the Normandeau report In a meeting between EPA and Jordan personnel in May 1986 EPA requested that a new Wetlands Assessment document be prepared A draft Wetlands Assessment report was delivered to EPA in January 1987

12 PURPOSE

According to the preamble to the National Contingency Plan (NCP) (40 CFR Part 300 Federal Register November 20 1985) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) actions will consider federal state and local environmental standards requirements criteria or limitations These include the Floodplain Management Executive Order (EO 11988) the Protection of Wetlands Executive Order (EO 11990) the Clean Water Act Section 404(b)(1) Guidelines and EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Additionally the Superfund Amendments and Reauthorization Act (SARA) of 1986 requires that remedial actions attain water quality criteria and any state requirement which is more stringent than any federal requirement this includes the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) Because it is possible that remedial actions implemented at the CEC site may affect wetlands and floodplains EPAs policy requires that a wetlands and floodplains assessment be incorporated into the planning of the remedial action The primary purposes of the Wetlands Assessment for the CEC site are to characterize wetlands and floodplains associated with the site evaluate present and future impacts to wetlands associated with contaminants from the site and provide sufficient information to support detailed evaluation of the impacts of remedial alternatives to wetlands in the FS and as necessary develop mitigative measures

13 APPROACH

In preparation for the Wetlands Assessment a number of relevant documents were reviewed These included the Draft RI report (Jordan 1986) the Remedial Action Master Plan (RAMP) (CDM 1983) and a preliminary Wetlands Assessment prepared for Jordan by Normandeau Associates (Normandeau 1985) Maps that were collected included the US Geological Survey (USGS) Taunton 7 12 quadrangle topographic map of the area (USGS 1978) the US Fish and Wildlife Service (USFampWS) National Wetlands Inventory Map (USFampWS 1977) the Flood Insurance Rate Map (FIRM) (FEMA 1982) and aerial photographs of the site area (EPA 1964-1982) Reference materials included A Method for Wetland Functional Assessment (Adamus 1983) Wetland Values Concepts and Methods for Wetland Evaluation (Reppert et al 1979) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al 1979) Also the Massachusetts Natural Heritage Program (Division of Fisheries

-2shy

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

NOTICE

The information in this document has been funded by the United States Environmental Protection Agency (EPA) under REM III Contract No 68-01-7250 to Ebasco Services Inc (EBASCO) This document has been formally released by Ebasco to the EPA This document does not represent however the EPAs position on policy and has not been formally released by the EPA

TABLE OF CONTENTS

SECTION TITLE PAGE NO

10 INTRODUCTION 1 11 Background 1 12 Purpose 2 13 Approach 2

20 WETLAND IDENTIFICATION AND CHARACTERIZATION 4 21 Identification and Location of Wetland

Areas 4 22 Biological Characterization 8

221 Terrestrial Organisms 8 222 Aquatic Organisms 10 223 Threatened and Endangered

o p 6 C X 6 S bull bull bull bull bull bull bull bull bull bull bull bull bull XU 23 Hydrogeologic Characterization 11

231 Surface Hydrology 11 232 Groundwater Hydrology 12 233 Geology 12 234 100-Year Flood Potential 12

30 WETLAND FUNCTIONAL ATTRIBUTES 15 3 1 Hydrologic Functions 15

311 Groundwater Recharge and Discharge 15

312 Flood Storage and Desynchronization 16

32 Habitat Functions 16 321 Wildlife Habitat 16 322 Aquatic Habitat 16

33 Water Quality Functions 17 331 Sediment Trapping 17 332 Nutrient Retention and Removal 17 333 Contaminant Retention and

Removal 17 334 Oxygen Production 18

34 Socioeconomic Functions 18 35 Summary of Wetland Functional

Attributes 18

- 1 shy

TABLE OF CONTENTS (continued)

SECTION TITLE PAGE NO

40 EFFECTS OF CONTAMINATION 19 41 Extent of Contamination 19

411 Sediments 19 412 Surface Water 22

42 Impacts to Wetlands 22 421 Ecotoxicity Assessment 22 422 Future Impacts 28

50 WETLANDS PROTECTION REGULATIONS 29

60 SUMMARY AND CONCLUSIONS 30

APPENDIX A - REFERENCES APPENDIX B - HAZARDOUS SUBSTANCE LIST AND CONTRACT

REQUIRED DETECTION LIMITS

- 1 1 shy

LIST OF TABLES

TABLE TITLE PAGE NO

2-1 Plant Species Observed in the Wooded Swamp and Wet Area on September 11 1985 and Relative Abundance Estimates 9

4-1 Organic Contaminants Detected in Soils Sediments in the Wet Area 20

4-2 Organic Contaminants Detected in Soils Sediments in the Drainage Ditch Drainage Canal and Wooded Swamp 21

4-3 Organic Contaminants Detected in Surface Waters 23

4-4 Ecotoxicity Test Results and Ambient Water Quality Criteria for Selected Contaminants Detected in Wetlands at the CEC Site 25

4-5 Maximum Levels of Inorganic Constituents in Surface Waters and Ambient Water Quality Criteria 27

I bull bull

- 1 1 1 shy

LIST OF FIGURES

FIGURE TITLE PAGE NO

2-1 Site Location Map 5

2-2 National Wetlands Inventory Map 6

2-3 Location of Wetland Areas and Sampling Locations 7

2-4 Location of the 100-year Flood Plain 13

-IVshy

10 INTRODUCTION

11 BACKGROUND

The Cannons Engineering Corporation (CEC) site inMassachusetts was a waste handling operationchemical wastes in tanks and drums for on-siteBased on verbal communication with the Bridgewater

Bridg which incine fire

ewater stored ration chief

it is known that the incinerator was used frequently for a period of time in the mid-1970s between 1974 and 1980 CECs hazardous waste handling license was revoked by the Massachusetts Executive Office of Environmental Affairs (EOEA) in 1980 because of alleged reporting and waste handling violations CEC attempted to comply with the conditions placed on their activities by the court but was forced to cease operations at the site in November 1980 due to financial and legal difficulties Approximately 155000 gallons of sludge and liquid wastes were left at the site in drums and bulk storage at the time of closure Between 1980 and 1982 site inspections sampling and analysis activities were performed by the Massachusetts Department of Environmental Quality Engineering (DEQE) and a US Environmental Protection Agency (EPA) Field Investigation Team (FIT) to determine the presence of chemical contamination at the site In December 1982 the site was included in the EPA Superfund program The waste material stored on-site was removed by Jetline Services from October to December 1982

In October 1983 EC Jordan Co (Jordan) was engaged by NUS Corporation (NUS) to conduct a Remedial Investigation and Feasibility Study (RIFS) at the site NUS acted as the EPA Zone 1 Contractor during the period from 1982 to 1986 for Performance of Remedial Response Activities at Uncontrolled Hazardous Substance Facilities A draft RI report based on the findings of the original scope of work was submitted to the EPA in June 1985 A supplemental investigation was completed at the site in August 1985 and the results were incorporated into a draft RI report of June 1986 In August 1986 Ebasco Services Inc (Ebasco) became the new contractor under the REM III Program A second draft RI report was prepared in November 1986 Investigations conducted at the site have determined that chemical contamination includes volatile organics semivolatile organics pesticides PCBs and metals

In April 1986 Jordan was engaged by NUS to prepare an Endangerment Assessment (EA) of the site A draft EA report was prepared for Ebasco under the REM III Program in December 1986

The ecological systems on and adjacent to the site have been described in a baseline investigation that was prepared for Jordan by Normandeau Associates Inc in October 1985 In

-1shy

April 1986 NUS engaged Jordan to revise the Normandeau report In a meeting between EPA and Jordan personnel in May 1986 EPA requested that a new Wetlands Assessment document be prepared A draft Wetlands Assessment report was delivered to EPA in January 1987

12 PURPOSE

According to the preamble to the National Contingency Plan (NCP) (40 CFR Part 300 Federal Register November 20 1985) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) actions will consider federal state and local environmental standards requirements criteria or limitations These include the Floodplain Management Executive Order (EO 11988) the Protection of Wetlands Executive Order (EO 11990) the Clean Water Act Section 404(b)(1) Guidelines and EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Additionally the Superfund Amendments and Reauthorization Act (SARA) of 1986 requires that remedial actions attain water quality criteria and any state requirement which is more stringent than any federal requirement this includes the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) Because it is possible that remedial actions implemented at the CEC site may affect wetlands and floodplains EPAs policy requires that a wetlands and floodplains assessment be incorporated into the planning of the remedial action The primary purposes of the Wetlands Assessment for the CEC site are to characterize wetlands and floodplains associated with the site evaluate present and future impacts to wetlands associated with contaminants from the site and provide sufficient information to support detailed evaluation of the impacts of remedial alternatives to wetlands in the FS and as necessary develop mitigative measures

13 APPROACH

In preparation for the Wetlands Assessment a number of relevant documents were reviewed These included the Draft RI report (Jordan 1986) the Remedial Action Master Plan (RAMP) (CDM 1983) and a preliminary Wetlands Assessment prepared for Jordan by Normandeau Associates (Normandeau 1985) Maps that were collected included the US Geological Survey (USGS) Taunton 7 12 quadrangle topographic map of the area (USGS 1978) the US Fish and Wildlife Service (USFampWS) National Wetlands Inventory Map (USFampWS 1977) the Flood Insurance Rate Map (FIRM) (FEMA 1982) and aerial photographs of the site area (EPA 1964-1982) Reference materials included A Method for Wetland Functional Assessment (Adamus 1983) Wetland Values Concepts and Methods for Wetland Evaluation (Reppert et al 1979) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al 1979) Also the Massachusetts Natural Heritage Program (Division of Fisheries

-2shy

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

TABLE OF CONTENTS

SECTION TITLE PAGE NO

10 INTRODUCTION 1 11 Background 1 12 Purpose 2 13 Approach 2

20 WETLAND IDENTIFICATION AND CHARACTERIZATION 4 21 Identification and Location of Wetland

Areas 4 22 Biological Characterization 8

221 Terrestrial Organisms 8 222 Aquatic Organisms 10 223 Threatened and Endangered

o p 6 C X 6 S bull bull bull bull bull bull bull bull bull bull bull bull bull XU 23 Hydrogeologic Characterization 11

231 Surface Hydrology 11 232 Groundwater Hydrology 12 233 Geology 12 234 100-Year Flood Potential 12

30 WETLAND FUNCTIONAL ATTRIBUTES 15 3 1 Hydrologic Functions 15

311 Groundwater Recharge and Discharge 15

312 Flood Storage and Desynchronization 16

32 Habitat Functions 16 321 Wildlife Habitat 16 322 Aquatic Habitat 16

33 Water Quality Functions 17 331 Sediment Trapping 17 332 Nutrient Retention and Removal 17 333 Contaminant Retention and

Removal 17 334 Oxygen Production 18

34 Socioeconomic Functions 18 35 Summary of Wetland Functional

Attributes 18

- 1 shy

TABLE OF CONTENTS (continued)

SECTION TITLE PAGE NO

40 EFFECTS OF CONTAMINATION 19 41 Extent of Contamination 19

411 Sediments 19 412 Surface Water 22

42 Impacts to Wetlands 22 421 Ecotoxicity Assessment 22 422 Future Impacts 28

50 WETLANDS PROTECTION REGULATIONS 29

60 SUMMARY AND CONCLUSIONS 30

APPENDIX A - REFERENCES APPENDIX B - HAZARDOUS SUBSTANCE LIST AND CONTRACT

REQUIRED DETECTION LIMITS

- 1 1 shy

LIST OF TABLES

TABLE TITLE PAGE NO

2-1 Plant Species Observed in the Wooded Swamp and Wet Area on September 11 1985 and Relative Abundance Estimates 9

4-1 Organic Contaminants Detected in Soils Sediments in the Wet Area 20

4-2 Organic Contaminants Detected in Soils Sediments in the Drainage Ditch Drainage Canal and Wooded Swamp 21

4-3 Organic Contaminants Detected in Surface Waters 23

4-4 Ecotoxicity Test Results and Ambient Water Quality Criteria for Selected Contaminants Detected in Wetlands at the CEC Site 25

4-5 Maximum Levels of Inorganic Constituents in Surface Waters and Ambient Water Quality Criteria 27

I bull bull

- 1 1 1 shy

LIST OF FIGURES

FIGURE TITLE PAGE NO

2-1 Site Location Map 5

2-2 National Wetlands Inventory Map 6

2-3 Location of Wetland Areas and Sampling Locations 7

2-4 Location of the 100-year Flood Plain 13

-IVshy

10 INTRODUCTION

11 BACKGROUND

The Cannons Engineering Corporation (CEC) site inMassachusetts was a waste handling operationchemical wastes in tanks and drums for on-siteBased on verbal communication with the Bridgewater

Bridg which incine fire

ewater stored ration chief

it is known that the incinerator was used frequently for a period of time in the mid-1970s between 1974 and 1980 CECs hazardous waste handling license was revoked by the Massachusetts Executive Office of Environmental Affairs (EOEA) in 1980 because of alleged reporting and waste handling violations CEC attempted to comply with the conditions placed on their activities by the court but was forced to cease operations at the site in November 1980 due to financial and legal difficulties Approximately 155000 gallons of sludge and liquid wastes were left at the site in drums and bulk storage at the time of closure Between 1980 and 1982 site inspections sampling and analysis activities were performed by the Massachusetts Department of Environmental Quality Engineering (DEQE) and a US Environmental Protection Agency (EPA) Field Investigation Team (FIT) to determine the presence of chemical contamination at the site In December 1982 the site was included in the EPA Superfund program The waste material stored on-site was removed by Jetline Services from October to December 1982

In October 1983 EC Jordan Co (Jordan) was engaged by NUS Corporation (NUS) to conduct a Remedial Investigation and Feasibility Study (RIFS) at the site NUS acted as the EPA Zone 1 Contractor during the period from 1982 to 1986 for Performance of Remedial Response Activities at Uncontrolled Hazardous Substance Facilities A draft RI report based on the findings of the original scope of work was submitted to the EPA in June 1985 A supplemental investigation was completed at the site in August 1985 and the results were incorporated into a draft RI report of June 1986 In August 1986 Ebasco Services Inc (Ebasco) became the new contractor under the REM III Program A second draft RI report was prepared in November 1986 Investigations conducted at the site have determined that chemical contamination includes volatile organics semivolatile organics pesticides PCBs and metals

In April 1986 Jordan was engaged by NUS to prepare an Endangerment Assessment (EA) of the site A draft EA report was prepared for Ebasco under the REM III Program in December 1986

The ecological systems on and adjacent to the site have been described in a baseline investigation that was prepared for Jordan by Normandeau Associates Inc in October 1985 In

-1shy

April 1986 NUS engaged Jordan to revise the Normandeau report In a meeting between EPA and Jordan personnel in May 1986 EPA requested that a new Wetlands Assessment document be prepared A draft Wetlands Assessment report was delivered to EPA in January 1987

12 PURPOSE

According to the preamble to the National Contingency Plan (NCP) (40 CFR Part 300 Federal Register November 20 1985) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) actions will consider federal state and local environmental standards requirements criteria or limitations These include the Floodplain Management Executive Order (EO 11988) the Protection of Wetlands Executive Order (EO 11990) the Clean Water Act Section 404(b)(1) Guidelines and EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Additionally the Superfund Amendments and Reauthorization Act (SARA) of 1986 requires that remedial actions attain water quality criteria and any state requirement which is more stringent than any federal requirement this includes the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) Because it is possible that remedial actions implemented at the CEC site may affect wetlands and floodplains EPAs policy requires that a wetlands and floodplains assessment be incorporated into the planning of the remedial action The primary purposes of the Wetlands Assessment for the CEC site are to characterize wetlands and floodplains associated with the site evaluate present and future impacts to wetlands associated with contaminants from the site and provide sufficient information to support detailed evaluation of the impacts of remedial alternatives to wetlands in the FS and as necessary develop mitigative measures

13 APPROACH

In preparation for the Wetlands Assessment a number of relevant documents were reviewed These included the Draft RI report (Jordan 1986) the Remedial Action Master Plan (RAMP) (CDM 1983) and a preliminary Wetlands Assessment prepared for Jordan by Normandeau Associates (Normandeau 1985) Maps that were collected included the US Geological Survey (USGS) Taunton 7 12 quadrangle topographic map of the area (USGS 1978) the US Fish and Wildlife Service (USFampWS) National Wetlands Inventory Map (USFampWS 1977) the Flood Insurance Rate Map (FIRM) (FEMA 1982) and aerial photographs of the site area (EPA 1964-1982) Reference materials included A Method for Wetland Functional Assessment (Adamus 1983) Wetland Values Concepts and Methods for Wetland Evaluation (Reppert et al 1979) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al 1979) Also the Massachusetts Natural Heritage Program (Division of Fisheries

-2shy

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

TABLE OF CONTENTS (continued)

SECTION TITLE PAGE NO

40 EFFECTS OF CONTAMINATION 19 41 Extent of Contamination 19

411 Sediments 19 412 Surface Water 22

42 Impacts to Wetlands 22 421 Ecotoxicity Assessment 22 422 Future Impacts 28

50 WETLANDS PROTECTION REGULATIONS 29

60 SUMMARY AND CONCLUSIONS 30

APPENDIX A - REFERENCES APPENDIX B - HAZARDOUS SUBSTANCE LIST AND CONTRACT

REQUIRED DETECTION LIMITS

- 1 1 shy

LIST OF TABLES

TABLE TITLE PAGE NO

2-1 Plant Species Observed in the Wooded Swamp and Wet Area on September 11 1985 and Relative Abundance Estimates 9

4-1 Organic Contaminants Detected in Soils Sediments in the Wet Area 20

4-2 Organic Contaminants Detected in Soils Sediments in the Drainage Ditch Drainage Canal and Wooded Swamp 21

4-3 Organic Contaminants Detected in Surface Waters 23

4-4 Ecotoxicity Test Results and Ambient Water Quality Criteria for Selected Contaminants Detected in Wetlands at the CEC Site 25

4-5 Maximum Levels of Inorganic Constituents in Surface Waters and Ambient Water Quality Criteria 27

I bull bull

- 1 1 1 shy

LIST OF FIGURES

FIGURE TITLE PAGE NO

2-1 Site Location Map 5

2-2 National Wetlands Inventory Map 6

2-3 Location of Wetland Areas and Sampling Locations 7

2-4 Location of the 100-year Flood Plain 13

-IVshy

10 INTRODUCTION

11 BACKGROUND

The Cannons Engineering Corporation (CEC) site inMassachusetts was a waste handling operationchemical wastes in tanks and drums for on-siteBased on verbal communication with the Bridgewater

Bridg which incine fire

ewater stored ration chief

it is known that the incinerator was used frequently for a period of time in the mid-1970s between 1974 and 1980 CECs hazardous waste handling license was revoked by the Massachusetts Executive Office of Environmental Affairs (EOEA) in 1980 because of alleged reporting and waste handling violations CEC attempted to comply with the conditions placed on their activities by the court but was forced to cease operations at the site in November 1980 due to financial and legal difficulties Approximately 155000 gallons of sludge and liquid wastes were left at the site in drums and bulk storage at the time of closure Between 1980 and 1982 site inspections sampling and analysis activities were performed by the Massachusetts Department of Environmental Quality Engineering (DEQE) and a US Environmental Protection Agency (EPA) Field Investigation Team (FIT) to determine the presence of chemical contamination at the site In December 1982 the site was included in the EPA Superfund program The waste material stored on-site was removed by Jetline Services from October to December 1982

In October 1983 EC Jordan Co (Jordan) was engaged by NUS Corporation (NUS) to conduct a Remedial Investigation and Feasibility Study (RIFS) at the site NUS acted as the EPA Zone 1 Contractor during the period from 1982 to 1986 for Performance of Remedial Response Activities at Uncontrolled Hazardous Substance Facilities A draft RI report based on the findings of the original scope of work was submitted to the EPA in June 1985 A supplemental investigation was completed at the site in August 1985 and the results were incorporated into a draft RI report of June 1986 In August 1986 Ebasco Services Inc (Ebasco) became the new contractor under the REM III Program A second draft RI report was prepared in November 1986 Investigations conducted at the site have determined that chemical contamination includes volatile organics semivolatile organics pesticides PCBs and metals

In April 1986 Jordan was engaged by NUS to prepare an Endangerment Assessment (EA) of the site A draft EA report was prepared for Ebasco under the REM III Program in December 1986

The ecological systems on and adjacent to the site have been described in a baseline investigation that was prepared for Jordan by Normandeau Associates Inc in October 1985 In

-1shy

April 1986 NUS engaged Jordan to revise the Normandeau report In a meeting between EPA and Jordan personnel in May 1986 EPA requested that a new Wetlands Assessment document be prepared A draft Wetlands Assessment report was delivered to EPA in January 1987

12 PURPOSE

According to the preamble to the National Contingency Plan (NCP) (40 CFR Part 300 Federal Register November 20 1985) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) actions will consider federal state and local environmental standards requirements criteria or limitations These include the Floodplain Management Executive Order (EO 11988) the Protection of Wetlands Executive Order (EO 11990) the Clean Water Act Section 404(b)(1) Guidelines and EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Additionally the Superfund Amendments and Reauthorization Act (SARA) of 1986 requires that remedial actions attain water quality criteria and any state requirement which is more stringent than any federal requirement this includes the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) Because it is possible that remedial actions implemented at the CEC site may affect wetlands and floodplains EPAs policy requires that a wetlands and floodplains assessment be incorporated into the planning of the remedial action The primary purposes of the Wetlands Assessment for the CEC site are to characterize wetlands and floodplains associated with the site evaluate present and future impacts to wetlands associated with contaminants from the site and provide sufficient information to support detailed evaluation of the impacts of remedial alternatives to wetlands in the FS and as necessary develop mitigative measures

13 APPROACH

In preparation for the Wetlands Assessment a number of relevant documents were reviewed These included the Draft RI report (Jordan 1986) the Remedial Action Master Plan (RAMP) (CDM 1983) and a preliminary Wetlands Assessment prepared for Jordan by Normandeau Associates (Normandeau 1985) Maps that were collected included the US Geological Survey (USGS) Taunton 7 12 quadrangle topographic map of the area (USGS 1978) the US Fish and Wildlife Service (USFampWS) National Wetlands Inventory Map (USFampWS 1977) the Flood Insurance Rate Map (FIRM) (FEMA 1982) and aerial photographs of the site area (EPA 1964-1982) Reference materials included A Method for Wetland Functional Assessment (Adamus 1983) Wetland Values Concepts and Methods for Wetland Evaluation (Reppert et al 1979) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al 1979) Also the Massachusetts Natural Heritage Program (Division of Fisheries

-2shy

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

LIST OF TABLES

TABLE TITLE PAGE NO

2-1 Plant Species Observed in the Wooded Swamp and Wet Area on September 11 1985 and Relative Abundance Estimates 9

4-1 Organic Contaminants Detected in Soils Sediments in the Wet Area 20

4-2 Organic Contaminants Detected in Soils Sediments in the Drainage Ditch Drainage Canal and Wooded Swamp 21

4-3 Organic Contaminants Detected in Surface Waters 23

4-4 Ecotoxicity Test Results and Ambient Water Quality Criteria for Selected Contaminants Detected in Wetlands at the CEC Site 25

4-5 Maximum Levels of Inorganic Constituents in Surface Waters and Ambient Water Quality Criteria 27

I bull bull

- 1 1 1 shy

LIST OF FIGURES

FIGURE TITLE PAGE NO

2-1 Site Location Map 5

2-2 National Wetlands Inventory Map 6

2-3 Location of Wetland Areas and Sampling Locations 7

2-4 Location of the 100-year Flood Plain 13

-IVshy

10 INTRODUCTION

11 BACKGROUND

The Cannons Engineering Corporation (CEC) site inMassachusetts was a waste handling operationchemical wastes in tanks and drums for on-siteBased on verbal communication with the Bridgewater

Bridg which incine fire

ewater stored ration chief

it is known that the incinerator was used frequently for a period of time in the mid-1970s between 1974 and 1980 CECs hazardous waste handling license was revoked by the Massachusetts Executive Office of Environmental Affairs (EOEA) in 1980 because of alleged reporting and waste handling violations CEC attempted to comply with the conditions placed on their activities by the court but was forced to cease operations at the site in November 1980 due to financial and legal difficulties Approximately 155000 gallons of sludge and liquid wastes were left at the site in drums and bulk storage at the time of closure Between 1980 and 1982 site inspections sampling and analysis activities were performed by the Massachusetts Department of Environmental Quality Engineering (DEQE) and a US Environmental Protection Agency (EPA) Field Investigation Team (FIT) to determine the presence of chemical contamination at the site In December 1982 the site was included in the EPA Superfund program The waste material stored on-site was removed by Jetline Services from October to December 1982

In October 1983 EC Jordan Co (Jordan) was engaged by NUS Corporation (NUS) to conduct a Remedial Investigation and Feasibility Study (RIFS) at the site NUS acted as the EPA Zone 1 Contractor during the period from 1982 to 1986 for Performance of Remedial Response Activities at Uncontrolled Hazardous Substance Facilities A draft RI report based on the findings of the original scope of work was submitted to the EPA in June 1985 A supplemental investigation was completed at the site in August 1985 and the results were incorporated into a draft RI report of June 1986 In August 1986 Ebasco Services Inc (Ebasco) became the new contractor under the REM III Program A second draft RI report was prepared in November 1986 Investigations conducted at the site have determined that chemical contamination includes volatile organics semivolatile organics pesticides PCBs and metals

In April 1986 Jordan was engaged by NUS to prepare an Endangerment Assessment (EA) of the site A draft EA report was prepared for Ebasco under the REM III Program in December 1986

The ecological systems on and adjacent to the site have been described in a baseline investigation that was prepared for Jordan by Normandeau Associates Inc in October 1985 In

-1shy

April 1986 NUS engaged Jordan to revise the Normandeau report In a meeting between EPA and Jordan personnel in May 1986 EPA requested that a new Wetlands Assessment document be prepared A draft Wetlands Assessment report was delivered to EPA in January 1987

12 PURPOSE

According to the preamble to the National Contingency Plan (NCP) (40 CFR Part 300 Federal Register November 20 1985) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) actions will consider federal state and local environmental standards requirements criteria or limitations These include the Floodplain Management Executive Order (EO 11988) the Protection of Wetlands Executive Order (EO 11990) the Clean Water Act Section 404(b)(1) Guidelines and EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Additionally the Superfund Amendments and Reauthorization Act (SARA) of 1986 requires that remedial actions attain water quality criteria and any state requirement which is more stringent than any federal requirement this includes the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) Because it is possible that remedial actions implemented at the CEC site may affect wetlands and floodplains EPAs policy requires that a wetlands and floodplains assessment be incorporated into the planning of the remedial action The primary purposes of the Wetlands Assessment for the CEC site are to characterize wetlands and floodplains associated with the site evaluate present and future impacts to wetlands associated with contaminants from the site and provide sufficient information to support detailed evaluation of the impacts of remedial alternatives to wetlands in the FS and as necessary develop mitigative measures

13 APPROACH

In preparation for the Wetlands Assessment a number of relevant documents were reviewed These included the Draft RI report (Jordan 1986) the Remedial Action Master Plan (RAMP) (CDM 1983) and a preliminary Wetlands Assessment prepared for Jordan by Normandeau Associates (Normandeau 1985) Maps that were collected included the US Geological Survey (USGS) Taunton 7 12 quadrangle topographic map of the area (USGS 1978) the US Fish and Wildlife Service (USFampWS) National Wetlands Inventory Map (USFampWS 1977) the Flood Insurance Rate Map (FIRM) (FEMA 1982) and aerial photographs of the site area (EPA 1964-1982) Reference materials included A Method for Wetland Functional Assessment (Adamus 1983) Wetland Values Concepts and Methods for Wetland Evaluation (Reppert et al 1979) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al 1979) Also the Massachusetts Natural Heritage Program (Division of Fisheries

-2shy

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

LIST OF FIGURES

FIGURE TITLE PAGE NO

2-1 Site Location Map 5

2-2 National Wetlands Inventory Map 6

2-3 Location of Wetland Areas and Sampling Locations 7

2-4 Location of the 100-year Flood Plain 13

-IVshy

10 INTRODUCTION

11 BACKGROUND

The Cannons Engineering Corporation (CEC) site inMassachusetts was a waste handling operationchemical wastes in tanks and drums for on-siteBased on verbal communication with the Bridgewater

Bridg which incine fire

ewater stored ration chief

it is known that the incinerator was used frequently for a period of time in the mid-1970s between 1974 and 1980 CECs hazardous waste handling license was revoked by the Massachusetts Executive Office of Environmental Affairs (EOEA) in 1980 because of alleged reporting and waste handling violations CEC attempted to comply with the conditions placed on their activities by the court but was forced to cease operations at the site in November 1980 due to financial and legal difficulties Approximately 155000 gallons of sludge and liquid wastes were left at the site in drums and bulk storage at the time of closure Between 1980 and 1982 site inspections sampling and analysis activities were performed by the Massachusetts Department of Environmental Quality Engineering (DEQE) and a US Environmental Protection Agency (EPA) Field Investigation Team (FIT) to determine the presence of chemical contamination at the site In December 1982 the site was included in the EPA Superfund program The waste material stored on-site was removed by Jetline Services from October to December 1982

In October 1983 EC Jordan Co (Jordan) was engaged by NUS Corporation (NUS) to conduct a Remedial Investigation and Feasibility Study (RIFS) at the site NUS acted as the EPA Zone 1 Contractor during the period from 1982 to 1986 for Performance of Remedial Response Activities at Uncontrolled Hazardous Substance Facilities A draft RI report based on the findings of the original scope of work was submitted to the EPA in June 1985 A supplemental investigation was completed at the site in August 1985 and the results were incorporated into a draft RI report of June 1986 In August 1986 Ebasco Services Inc (Ebasco) became the new contractor under the REM III Program A second draft RI report was prepared in November 1986 Investigations conducted at the site have determined that chemical contamination includes volatile organics semivolatile organics pesticides PCBs and metals

In April 1986 Jordan was engaged by NUS to prepare an Endangerment Assessment (EA) of the site A draft EA report was prepared for Ebasco under the REM III Program in December 1986

The ecological systems on and adjacent to the site have been described in a baseline investigation that was prepared for Jordan by Normandeau Associates Inc in October 1985 In

-1shy

April 1986 NUS engaged Jordan to revise the Normandeau report In a meeting between EPA and Jordan personnel in May 1986 EPA requested that a new Wetlands Assessment document be prepared A draft Wetlands Assessment report was delivered to EPA in January 1987

12 PURPOSE

According to the preamble to the National Contingency Plan (NCP) (40 CFR Part 300 Federal Register November 20 1985) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) actions will consider federal state and local environmental standards requirements criteria or limitations These include the Floodplain Management Executive Order (EO 11988) the Protection of Wetlands Executive Order (EO 11990) the Clean Water Act Section 404(b)(1) Guidelines and EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Additionally the Superfund Amendments and Reauthorization Act (SARA) of 1986 requires that remedial actions attain water quality criteria and any state requirement which is more stringent than any federal requirement this includes the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) Because it is possible that remedial actions implemented at the CEC site may affect wetlands and floodplains EPAs policy requires that a wetlands and floodplains assessment be incorporated into the planning of the remedial action The primary purposes of the Wetlands Assessment for the CEC site are to characterize wetlands and floodplains associated with the site evaluate present and future impacts to wetlands associated with contaminants from the site and provide sufficient information to support detailed evaluation of the impacts of remedial alternatives to wetlands in the FS and as necessary develop mitigative measures

13 APPROACH

In preparation for the Wetlands Assessment a number of relevant documents were reviewed These included the Draft RI report (Jordan 1986) the Remedial Action Master Plan (RAMP) (CDM 1983) and a preliminary Wetlands Assessment prepared for Jordan by Normandeau Associates (Normandeau 1985) Maps that were collected included the US Geological Survey (USGS) Taunton 7 12 quadrangle topographic map of the area (USGS 1978) the US Fish and Wildlife Service (USFampWS) National Wetlands Inventory Map (USFampWS 1977) the Flood Insurance Rate Map (FIRM) (FEMA 1982) and aerial photographs of the site area (EPA 1964-1982) Reference materials included A Method for Wetland Functional Assessment (Adamus 1983) Wetland Values Concepts and Methods for Wetland Evaluation (Reppert et al 1979) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al 1979) Also the Massachusetts Natural Heritage Program (Division of Fisheries

-2shy

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

10 INTRODUCTION

11 BACKGROUND

The Cannons Engineering Corporation (CEC) site inMassachusetts was a waste handling operationchemical wastes in tanks and drums for on-siteBased on verbal communication with the Bridgewater

Bridg which incine fire

ewater stored ration chief

it is known that the incinerator was used frequently for a period of time in the mid-1970s between 1974 and 1980 CECs hazardous waste handling license was revoked by the Massachusetts Executive Office of Environmental Affairs (EOEA) in 1980 because of alleged reporting and waste handling violations CEC attempted to comply with the conditions placed on their activities by the court but was forced to cease operations at the site in November 1980 due to financial and legal difficulties Approximately 155000 gallons of sludge and liquid wastes were left at the site in drums and bulk storage at the time of closure Between 1980 and 1982 site inspections sampling and analysis activities were performed by the Massachusetts Department of Environmental Quality Engineering (DEQE) and a US Environmental Protection Agency (EPA) Field Investigation Team (FIT) to determine the presence of chemical contamination at the site In December 1982 the site was included in the EPA Superfund program The waste material stored on-site was removed by Jetline Services from October to December 1982

In October 1983 EC Jordan Co (Jordan) was engaged by NUS Corporation (NUS) to conduct a Remedial Investigation and Feasibility Study (RIFS) at the site NUS acted as the EPA Zone 1 Contractor during the period from 1982 to 1986 for Performance of Remedial Response Activities at Uncontrolled Hazardous Substance Facilities A draft RI report based on the findings of the original scope of work was submitted to the EPA in June 1985 A supplemental investigation was completed at the site in August 1985 and the results were incorporated into a draft RI report of June 1986 In August 1986 Ebasco Services Inc (Ebasco) became the new contractor under the REM III Program A second draft RI report was prepared in November 1986 Investigations conducted at the site have determined that chemical contamination includes volatile organics semivolatile organics pesticides PCBs and metals

In April 1986 Jordan was engaged by NUS to prepare an Endangerment Assessment (EA) of the site A draft EA report was prepared for Ebasco under the REM III Program in December 1986

The ecological systems on and adjacent to the site have been described in a baseline investigation that was prepared for Jordan by Normandeau Associates Inc in October 1985 In

-1shy

April 1986 NUS engaged Jordan to revise the Normandeau report In a meeting between EPA and Jordan personnel in May 1986 EPA requested that a new Wetlands Assessment document be prepared A draft Wetlands Assessment report was delivered to EPA in January 1987

12 PURPOSE

According to the preamble to the National Contingency Plan (NCP) (40 CFR Part 300 Federal Register November 20 1985) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) actions will consider federal state and local environmental standards requirements criteria or limitations These include the Floodplain Management Executive Order (EO 11988) the Protection of Wetlands Executive Order (EO 11990) the Clean Water Act Section 404(b)(1) Guidelines and EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Additionally the Superfund Amendments and Reauthorization Act (SARA) of 1986 requires that remedial actions attain water quality criteria and any state requirement which is more stringent than any federal requirement this includes the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) Because it is possible that remedial actions implemented at the CEC site may affect wetlands and floodplains EPAs policy requires that a wetlands and floodplains assessment be incorporated into the planning of the remedial action The primary purposes of the Wetlands Assessment for the CEC site are to characterize wetlands and floodplains associated with the site evaluate present and future impacts to wetlands associated with contaminants from the site and provide sufficient information to support detailed evaluation of the impacts of remedial alternatives to wetlands in the FS and as necessary develop mitigative measures

13 APPROACH

In preparation for the Wetlands Assessment a number of relevant documents were reviewed These included the Draft RI report (Jordan 1986) the Remedial Action Master Plan (RAMP) (CDM 1983) and a preliminary Wetlands Assessment prepared for Jordan by Normandeau Associates (Normandeau 1985) Maps that were collected included the US Geological Survey (USGS) Taunton 7 12 quadrangle topographic map of the area (USGS 1978) the US Fish and Wildlife Service (USFampWS) National Wetlands Inventory Map (USFampWS 1977) the Flood Insurance Rate Map (FIRM) (FEMA 1982) and aerial photographs of the site area (EPA 1964-1982) Reference materials included A Method for Wetland Functional Assessment (Adamus 1983) Wetland Values Concepts and Methods for Wetland Evaluation (Reppert et al 1979) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al 1979) Also the Massachusetts Natural Heritage Program (Division of Fisheries

-2shy

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

April 1986 NUS engaged Jordan to revise the Normandeau report In a meeting between EPA and Jordan personnel in May 1986 EPA requested that a new Wetlands Assessment document be prepared A draft Wetlands Assessment report was delivered to EPA in January 1987

12 PURPOSE

According to the preamble to the National Contingency Plan (NCP) (40 CFR Part 300 Federal Register November 20 1985) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) actions will consider federal state and local environmental standards requirements criteria or limitations These include the Floodplain Management Executive Order (EO 11988) the Protection of Wetlands Executive Order (EO 11990) the Clean Water Act Section 404(b)(1) Guidelines and EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Additionally the Superfund Amendments and Reauthorization Act (SARA) of 1986 requires that remedial actions attain water quality criteria and any state requirement which is more stringent than any federal requirement this includes the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) Because it is possible that remedial actions implemented at the CEC site may affect wetlands and floodplains EPAs policy requires that a wetlands and floodplains assessment be incorporated into the planning of the remedial action The primary purposes of the Wetlands Assessment for the CEC site are to characterize wetlands and floodplains associated with the site evaluate present and future impacts to wetlands associated with contaminants from the site and provide sufficient information to support detailed evaluation of the impacts of remedial alternatives to wetlands in the FS and as necessary develop mitigative measures

13 APPROACH

In preparation for the Wetlands Assessment a number of relevant documents were reviewed These included the Draft RI report (Jordan 1986) the Remedial Action Master Plan (RAMP) (CDM 1983) and a preliminary Wetlands Assessment prepared for Jordan by Normandeau Associates (Normandeau 1985) Maps that were collected included the US Geological Survey (USGS) Taunton 7 12 quadrangle topographic map of the area (USGS 1978) the US Fish and Wildlife Service (USFampWS) National Wetlands Inventory Map (USFampWS 1977) the Flood Insurance Rate Map (FIRM) (FEMA 1982) and aerial photographs of the site area (EPA 1964-1982) Reference materials included A Method for Wetland Functional Assessment (Adamus 1983) Wetland Values Concepts and Methods for Wetland Evaluation (Reppert et al 1979) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al 1979) Also the Massachusetts Natural Heritage Program (Division of Fisheries

-2shy

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

and Wildlife) was contacted regarding information on threatened and endangered species in the site vicinity

Information from the sources listed previously was used to prepare this Wetlands Assessment which includes the following elements

o Wetland Identification and Characterization (Section 20)

o Wetland Functional Attributes (Section 30)

o Effects of Contamination (Section 40) and

o Wetlands Protection Regulations (Section 50)

As indicated in Section 12 this assessment describes the present and projected future status of the wetlands in the absence of remedial response The evaluation of alternatives proposed for site remediation and development of mitigative measures will be performed in the FS

-3shy

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

20 WETLAND IDENTIFICATION AND CHARACTERIZATION

21 IDENTIFICATION AND LOCATION OF WETLAND AREAS

The CEC site is located 25 miles south of Boston in the western portion of the Town of Bridgewater Plymouth County Massachusetts at approximately 41 58 30 latitude and 71 01 30 longitude as shown in the Taunton 7-12 quadrangle map (USGS 1978) (Figure 2-1) As shown in Figure 2-1 the site is located adjacent to an arm of the Hockomock Swamp a wetland located in the 56-square-mile Town River watershed Because of the location of the site and the large size of the Hockomock Swamp (approximately 10 square miles or 6400 acres) compared to the small size of the area adjacent to the site (approximately 15 acres) the potentially affected area comprises an extremely small portion (02) of the entire Hockomock Swamp Furthermore it is not expected that the swamp will be significantly affected by such contaminants or results of any remedial action implemented at the site given the cunount and distribution of contaminants thought to be present physical and chemical properties and the large size of the swamp For these reasons the Wetlands Assessment for the CEC site will focus on the approximately 15-acre arm of the Hockomock Swamp adjacent to the site

The USFampWS National Wetlands Inventory (NWI) map of the site and surrounding area is presented in Figure 2-2 This inventory is based on aerial photography and use of a classification scheme developed by Cowardin et al (1979) The NWI map identifies the area of the Hockomock Swamp adjacent to the site (referred to as the wooded swamp in this report) as palustrine forestedscrub-shrxib broad-leaved deciduous (PFOSSl) wetland Field investigations by Normandeau personnel agreed in general with this classification and provided greater detail regarding the composition of vegetation in wetlands at the site

There is also a wet area on the site itself (approximately 34-acre in size) that is not shown on the NWI map but was observed during site investigations which was created several years ago when the surface of the site was excavated down to the water table (see Figure 2-3) From aerial photographs taken before hazardous waste operations began at the site it appears that an upland community existed at the present location of the wet area It is probable that the berm separating the wet area from the wooded swamp to the south was also created at the time of this excavation This wet area does not contain the highly organic soils characteristic of a wetland However because the dominant vegetation in this area consists of wetland plant species it is classified as a wetland under the Massachusetts Wetlands Protection Laws (Massachusetts General Laws Chapter 131 Section 40) Both the wooded swamp and the wet area will be evaluated in this Wetlands Assessment

-4shy

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

QUADRANGLE LOCATION

SOURCE USGS QUADTAUNT0NMA712 MINUTE SERIES 1978

copy FIGURE 2-1 SITE LOCATION MAP

CANNONS ENGINEERING CORP SITE Ea WETLANDS ASSESSMENT 7 00 FEET US ENVIRONMENTAL PROTECTION AGENCY 2000

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

UEQEND P bull PALUSTRme ECOLOGICAL SYSTEM

FOIgtFORESTED BROAO-LEAVED DECDUOUS

copy 2000 4 0 0 0 FEET SsT gtScRUBAHRUB BROAO-LEAVEO DECDUOUS

EM -EMERGENT V UPLAND AREAS FIGURE SS

NATIONAL WETLANDS INVENTORY MAP CANNONS ENGINEERING CORP SITE

WETLANDS ASSESSMENT MAP SOURCE USFawSl977 US ENVIRONMENTAL PROTECTION AGENCY

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

i 7 LEGEND

^ MW-I TO MW-tO INITIAL lOmNS AND MONITOWNa WCLt lOCATtONS

^ MW-II TOMW-13 bullUMLEMENTAL BORINO AND MONITONINS W E U UlCATiQN

^^ I W - I SEDIMENT SAUPIE LOCATION

A SW-ZTQSWT fURFACE WATER AND lEDIMENT tAM^LE LOCATION

bull ^ SS-1 TO SS l l SURFACE SOIL SAUPLE LOCATION ^

E ^ W S - I T O W S - S WATER SAMPLE FROM UNDERGROUND TANK

O A-1 TO A J TENAX TUBE AIR SAMPLE LOCATION ^ j

bull ^ TNK WP-2 ABOVEGROUND TANK WIPE SAMPLE LOCATION

MT-BSN-1 DRAINAGE SYSTEM CATCH BASM SEDIMENT SAMPLE LOCATION

INTERPRETIVE GEOLOGIC PROFILE LOCATION i i ^ A raquo T O F S SURFACE SOL SAMPgE LOCATKW

O Cl TOGS BOH BAMPU I J O U T I O N fOH WMAMC CARBON

STORM DRAIN iA a

( bull

TCUPORARY KNCHUARK ( T M I )

bull WETUANO AREA LOCATION

APPROXIMATE LIMITS OF WETLAND AREA

m NQTES I AIR SAMPLE A-4 WAS ATTACHED TO A WORK PARTY

TEAM MEMBER DURING THE SITE RECONNAISSANCE CONDUCTED ON 4 - 3 - sect 4

t LOCATION OF MAGNETOMETER SURVEY IS SHOWN IN APPENDIX F-t

I SEE FIGURES AND 4 FDR INTERPRETIVE GEOLOCtC PROFILES ^

4 THE AW MSIOE THE EQUIPMENT READY AND TANK FARM BUILOINSS WAS SAMPLED USING (HEMICAU-Y REACTIVE INDICATING TUBES

^^Vfai ^

I bull

BABf MAPPRCP4laquoCD FROM k AITI tURVET COMPLlTCD i r f C JORDAN CO ON JUNi II M IS I t M A PLAN INTITLED bullRI06CWATEII INOUSTRIAt PARK RCVISID SUBDIVISION Of LAND IN bullmOGtWATIR MA OWNCO bull laquo BCNSON NCALTT TRUST SHEETS Of t DATED OCT I t l i r i MADE RT CA PICKERING ASSOCIATES INC CIVH (N6INEERt-LAM0laquoURV(T0RSlaquoEST (RlDGEVlATEM MA WAS UMD FOR RIFUKNCI TEMPORARY lENCHMARK (TIM I AT TNE INVERT lt0r A bull bull INCH CULVERT LOCATED ON THE EAST SIDE Of ROuTI 24 ILIVATION I U S F I E T I UtG t DATUM llaquo2laquo M SL OOorEET

ECJORDANCQ OONSULTMQ ENQMEERA

^ f 4 V t t gt kldil LOCATION OF WETLAND A R E A C ^

AND 8(^MPLINQ LOCATIONS j ^ f

WETLANDS ASSESSMENT f f CANNONS ENQMEEMM CORP M T I

BRIDOpoundVgtltATE|l MA

UtSi ENVIRONMENTAL PROTECTION AQENCY S I O I - 4 0

ASBHOWN ua FIGURE 2 - 3

I

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

22 BIOLOGICAL CHARACTERIZATION

221 Terrestrial Organisms

The wooded swamp contains three distinct vegetative strata which consist of the herbemergent shrub and tree layers (Normandeau Associates Preliminary Wetlands Assessment) (Normandeau 1985) The tree layer is composed principally of red maple while the dominant species in the shrub layer are highbush blueberry pepper bush and swamp azalea The primary species in the herb layer are sensitive fern marsh fern and water horehound A list of plant species observed in the wooded swamp and the wet area is presented in Table 2-1

Based on a site visit in June 1985 by the USFampWS bull regional biologist (Kenneth Carr) the birds most expected to utilize the wooded swamp are warblers (Parulidae) sparrows (Melospiza sp) and grosbeaks (Pheucticus sp) Because of the limited amount of open water little use by water fowl and wading birds is expected although the wood duck (Aix sponsa) and great blue heron (Ardea herodias) might utilize the canal It is probable that the larger southern portion of the wooded swamp (south of the canal) is used by birds such as the red-shouldered hawk (Buteo lineatus) broad-winged hawk (Buteo platvpterus) and barred owls (Strix varia) Actual sightings during the June visit included bluejay (Cvanocitta cristata) crow (Corvus brachyrhvnchos) hairy woodpecker (Dendrocopus villosus) wood thrush (Hylocichla mustelina) robin (Turdus migratorius) veery (Vireo olivaceous) song sparrow (Melospiza melodia) redwing blackbird (Agelaius phoeniceus) towhee (Pipilo sp) and numerous species of warblers (Parulidae)

Although not documented it is likely that a variety of mammals reptiles and amphibians inhabit or frequent the wooded swamp based on their habitat preferences and local occurrence The most common of these would include eastern chipmunk (Sylvilagus floridanus) racoon (Procyon lotor) grey squirrel (Seiurus carolinensis) woodchuck (Marmota monax) bullfrog (Rana catesbiana) green frog (Rana clamitans melanota) American toad (Bufo americanus) eastern garter snake (Thamnophis sirtalis sirtalis) northern water snake (Nerodia sipedon sipedon) eastern painted turtle fChrvsemys pieta picta) and common snapping turtle (Chelydra serpentina) (DeGraaf and Rudis 1983 Godin 1983)

As mentioned earlier the wet area was probably upland which was excavated down to the water table The perpetually saturated conditions there have allowed for colonization by plants suited for growth in wet soils Reed is the dominant plant species in the wet area Cattail bulirush and sedge also occur but make up a smaller portion of the flora

-8shy

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

TABLE 2-1

PLANT SPECIES OBSERVED IN THE WOODED SWAMP AND WET AREA ON SEPTEMBER 11 1985 AND RELATIVE ABUNDANCE ESTIMATES

Scientific Name

Typha latifolia Scirpus cyperinus Phragmites communis Solidago rugosa Eupatorium maculatum Carex lurida Juncus effusus Carex pseudocyperus Spiraea latifolia Polygonum sagittatum Impatiens biflora Juncus dichotomus Lythrum salicaria Eupatorium perfollatum Onoclea sensibilis Salix bebbiana Alnus rugosa Acer rubrum Clethra alnifolia Vaccinium corymbosum Rhododendron viscosum Ilex verticillata Thelypteris palustris Viburnum recognitum Polygonum punctatum Sparganium americanum Callitriche sp Eleocharis ovata Carex folliculata Lycopus virginicus Rhus vernix

Dominant Common

Common Name

Cattail Wool grass Reed Goldenrod Joe-Pye Weed Sedge Rush Sedge Meadow-sweet Thumb Tear Jewel-weed Rush Purple Loosestrife Boneset Sensitive Fern Willow Speckled Alder Red Maple Pepper-bush Highbush blueberry Swamp Azalea Holly Marsh Fern Arrow-wood Smartweed Bur-reed Water starwort Spike rush Sedge Water-horehound Poison-sumac

Occasional

Relative Abundance Doml Com2 Occ3

x x

X X

X X

X X X X X

X

X

X

X X X

X X

X X X X X

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

The wet area is similar in some ways to a robust shallow marsh as described by Golet and Larson (1974) because it contains reed and cattail Because the previous years growth persists into spring the authors state that these plants may provide spring cover for waterfowl bitterns Virginia and sora rails coots gallinules redwing blackbirds and other species During the winter these emergents can provide cover for cottontail rabbits and ring-necked pheasants It should be noted however that the use of the wet area by these species has not been docximented and that the presence of contamination in the wet area (see Section 41) may be resulting in avoidance of the wet area by wildlife Furthermore the wet area is small (approximately 34-acre) and does not contain a dense vegetative cover throughout decreasing the extent toexpected to provide wildlife habitat

which it can be

222 Aquatic Organisms

No aquatic biological investigation has been performed in wetlands at the CEC site However species in certain taxonomic groups are likely to be present in wetland soilssediments or surface waters (the drainage ditch) based on habitat preferences and local occurrence Major macroinvertebrate groups expected include the Oligochaeta (Tubificid worms) Odonata (dragonflies and damselflies) Diptera (midges true flies and mosquitoes) Crustacea (cladocerans and crayfish) Physidae (river snails) and Sphaeridae (freshwater mussels) Major aquatic vertebrate groups would include the Cyprinidae (minnows) and Ictaluridae (catfish and bullheads) Some of these groups (eg Oligochaeta Physidae and Ictaluridae) are capable of existing in adverse environments under conditions such as low dissolved oxygen variable pH variable temperatures diverse food sources and pollution It is possible that these groups are present and that the more sensitive groups are locally extinct because of these or other adverse conditions in wetlands at the site

223 Threatened and Endangered Species

The Massachusetts Natural Heritage Program was contacted for information regarding rare species and ecologically significant communities in the vicinity of Hockomock Swamp and Lake Nippenicket which is about 34 of a mile west of the site Several rare plant populations have been documented on the shores of Lake Nippenicket These plants are as follows

-10shy

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

Scientific Name Common Name Status

Ludwigia sphaerocarpa Round-fruited State Threatened False-loosestrife

Sabatia kennedyana Plymouth Gentian Special Concern

Utricularia biflora Two-flowered State Threatened Bladderwort

The populations of Ludwigia and Utricularia are both the largest in the state for those species numbering over 3500 and 650 plants respectively Based on a personal communication with the Massachusetts Natural Heritage Program the three species listed above are restricted to pond shore habitat (between low and high water level extremes) and would not be found in wetlands similar to those at the CEC site (red-maple swamp and cattail marsh) Therefore these species do not constitute a concern at this site

23 HYDROGEOLOGIC CHARACTERIZATION

Detailed assessments of hydrology and geology were presented in the Draft RI report (Jordan 1986) and the RAMP (CDM 1983) Only those hydrogeologic characteristics pertinent to wetlands associated with the CEC site will be summarized in this Wetlands Assessment

231 Surface Hvdrology

Surface runoff from the upland portion of the site (where operations took place) enters the wet area presximably via overland flow The wet area also receives surface flow from three storm drains located on the upland portion of the site Groundwater is also discharging to the wet area (see Section 232) The small pond at the eastern end of the wet area (see Figure 2-3) is a land surface depression and does not appear to have a surface outlet Surface runoff from the wet area and flow from the sources described previously enter the drainage canal to the south via a small drainage ditch at the western end of the wet area (see Figure 2-3)

The canal also receives drainage from First Street via a storm drain from an industrial area on the east side of First Street and from the upland area south of the site Water in the canal flows west and enters the main body of the Hockomock Swamp through a culvert under Route 24 This flow drains northward through the Hockomock Swamp toward the Town River which eventually enters the Taunton River It should be noted that the local watershed area of the site is only about 75 acres (drainage divides located approximately 04 and 02 mile to the

-11shy

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

south and east respectively) compared to the size of the Town River watershed which is 56 square miles The Hockomock Swamp (see Figure 2-1) comprises approximately 10 square miles of the Town River watershed

232 Groundwater Hvdrology

Precipitation is the primary source of local groundwater recharge at the CEC site which is believed to occur in the upland flat sandy portions of the site and areas to the north The wet area and other wet lowland areas south and west of the site (including the drainage canal) are areas of local groundwater discharge Upward vertical seepage gradients in bedrock at multi-well monitoring locations MW-4A4B and MW-6A6B (see Figure 2-3) indicate that groundwater in bedrock is flowing upward into the unconsolidated surficial deposits The local topography suggests that deeper groundwater flows westward before ultimately discharging into Hockomock Swamp In addition the topographic high at the southeast end of Lake Nippenicket (see Figure 2-1) suggests that the westerly component of deeper groundwater flow may not reach the lake due to recharge in this area and because the general trend of flow is northward toward the Town River

233 Geology

The surficial deposits at the CEC site consist of unconsolidated sand gravel and silt overlying bedrock The thickness of these deposits above the bedrock surface varies from 11 to 17 feet Fill and disturbed soils occur at the surface of the site The underlying glacial deposits are classified as ice contact and outwash strata glacial till soils were not identified at the site In the wet area on-site outwash soils occur at ground surface and consist principally of silt and fine sand Highly organic soils typically found in wetlands are not present in the wet area

The site is located within the Narragansett Basin portions of which are covered by thick silts and clays that were likely deposited in a glacial lake environment The lowland area of the Hockomock Swamp is representative of these deposits

The bedrock in the area of the site is mapped as Rhode Island Formation composed of sandstone shale and conglomerate Cores of bedrock beneath the site confirm the presence of sandstone and conglomerate

234 100-Year Flood Potential

The 100-year floodplain is shown as the shaded area labeled Zone A in Figure 2-4 Although base flood elevations are not shown on the map (no detailed flood potential study has been

-12shy

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

it- 7 V l i t I bullbull e-

SOURCE FEMAI982 LEGEND

ZONE A AREAS OF 100-YEAR FLOOD ZONE B AREAS BETWEEN LIMITS OF 100-YEAR

FLOOD AND 600-YEAR FLOOD ZONE C AREAS OF MINIMAL FLOODING F I G U R E 2 - ~ 4

LOCATION OF THE 100-YEAR FLOOD PLAIN CANNONS ENGINEERING CORP SITE

APPROXIMATE SCALE W E T L A N D S ASSESSMENT n - n ii I US ENVIRONMENTAL PROTECTION AGENCY

bull 800 0 800 FEET

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

performed in the vicinity of the site) comparison with the USGS topographic map (see Figure 2-1) indicates that the base elevation of the 100-year flood is slightly higher than 60 feet above mean sea level encompassing the Hockomock Swamp and portions of abutting upland areas Because the upland portion of the site lies between approximately 63 and 68 feet above mean sea level it is above the base elevation of the 100-year flood The wet area lies at approximately 62 feet above mean sea level hence it appears to be above the base elevation of the 100-year flood although this cannot be determined with certainty given the resolution of available flood boundary maps The wooded swamp is perpetually wet and lies within the boundaries of the 100-year floodplain It should be noted that the 100-year flood elevation is probably only slightly higher than annual flood elevations owing to the large flood storage capacity of the Hockomock Swamp (ie 75 billion gallons according to the Bridgewater Conservation Commission) This is illustrated by the fact that the boundaries of the 100-year and 500-year floods closely parallel those of the Hockomock Swamp

-14shy

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

30 WETLAND FUNCTIONAL ATTRIBUTES

Wetlands are often regulated in terms of protecting the functions they serve This is true for federal regulations such as the Clean Water Act Section 404(b)(1) Guidelines and the requirements of the NCP as well as state and local wetlands protection regulations Numerous quantitative and qualitative methods and techniques are available for evaluating wetland functions This Wetlands Assessment contains a qualitative evaluation which includes elements common to many quantitative techniques (see Adamus 1983) and incorporates the special requirements associated with a contaminated site as well Evaluation criteria used in this Wetlands Assessment are as follows

o Hydrologic Functions Based on flood storage and desynchronization and groundwater recharge and discharge

o Habitat Functions Based on density and number of vegetative strata diversity amount of edge (transitional zones of vegetation) food availability and water quality

o Water Quality Functions Evaluated according to potential for sediment trapping nutrient retention and removal contaminant retention and removal and oxygen production

o Socioeconomic Functions Evaluated in terms of aesthetics recreational usage educational resources historic importance and scientific value

Both the wet area and the wooded swamp have been qualitatively evaluated for each function so that their importance relative to each other and to other wetlands of similar type may be determined

31 HYDROLOGIC FUNCTIONS

311 Groundwater Recharge and Discharge

As described in Section 232 both the wet area (approximately 34-acre) and the wooded swamp (approximately 15 acres) are groundwater discharge areas Therefore they are not directly important in terms of groundwater supply via aquifer recharge Groundwater discharge however may indirectly relate to ground water supply by serving to maintain base flow during dry periods Because it is believed that groundwater discharge is occurring in large portions of the Hockomock Swamp the significance of groundwater discharge in the wet area and wooded swamp in terms of groundwater supply is limited because of their relatively small size

-15shy

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

312 Flood Storage and Desynchronization

The wooded swamp has the potential to become flooded (see Section 234) The culvert that conducts flow from the discharge canal under Route 24 into the Hockomock Swamp is a constricted outlet which increases the flood retention capacity of the wooded swamp Drainage into the wooded swamp will be detained and gradually released through the Route 24 culvert It is likely that this release will be desynchronized with releases from other basins in the Town River watershed thereby helping to prevent flooding in downstream channels notably the Town River and the Taunton River

It must be noted that the area of the wooded swamp is relatively small compared to the size of Hockomock Swamp Therefore its overall contribution in terms of flood prevention in the Town River (much of which flows through the Hockomock Swamp a wetland with large flood storage capacity) and the Taunton River will be small

32 HABITAT FUNCTIONS

321 Wildlife Habitat

As described in Section 22 a variety of wildlife has either been observed or would normally be expected to inhabit or frequent the wooded swamp and to a lesser extent the wet area Because the wooded swamp is much larger (approximately 15 acres) is relatively pristine compared to the wet area and possesses more wetland characteristics it is more valuable in terms of wildlife habitat The wooded swamp contains plants in the herbemergent shriib and tree strata which exhibit moderate floral diversity Therefore the wooded swamp is expected to provide valuable food and cover to a variety of wildlife While the wet area may offer some food and cover it is less valuable in terms of habitat because of its(approximately 34-acre) and lack of dense vegetthroughout

smallative

size cover

322 Aquatic Habitat

Wetlands such as the wooded swamp typically support a variety of benthic macroinvertebrates aquatic macrophytes phytoplankton and zooplankton and may also contain some fish It is possible that low levels of dissolved oxygen (measured in the field by Normandeau Associates personnel) and chemical contamination (see Section 41) have resulted in lower population densities for sensitive species at least in the drainage canal and the wet area As mentioned in Section 222 certain aquatic organisms can function in polluted or anoxic waters and therefore may persist at the site Overall however the value of the wet area and drainage ditch is low in terms of aquatic habitat The

-16shy

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

more pristine areas of the wooded swamp are probably comparable to other red maple swamps in terms of aquatic habitat

33 WATER QUALITY FUNCTIONS

331 Sediment Trapping

Sediments can become suspended in surface waters and transported to downstream water bodies where they may accumulate in undesirable locations Wetlands act to trap sediments suspended in surface water preventing their migration downstream

The wooded swamp is expected to be effective in terms of trapping sediments that flow into the Hockomock Swamp particularly during storm events which result in flooding of the drainage canal Likewise the wet area may serve to trap sediments suspended in runoff from the upland portion of the site However because there are no waterways or bodies of water immediately downstream the sediment-trapping ability of these wetlands is of little importance in terms of preventing sediment buildup in undesirable locations The wetlands may act however to prevent the migration of contaminants adsorbed to sediments to downstream locations (see Section 333)

332 Nutrient Retention and Removal

Wetlands can act to reduce the concentration of excess nutrients (eg nitrogen and phosphorus) which would otherwise stimulate algal blooms in surface waters and excess macrophyte production in receiving waters Land use in the watershed draining to the wooded swampwet area is primarily light industrial and residential indicating that no large sources of nutrients (eg agricultural operations) exist there However some nutrients are nonetheless expected due to animal wastes and natural degradation of organic matter The wooded swamp and the wet area are both expected to be effective in retaining and removing nutrients from surface waters However because the nearest receiving body of water is Lake Nippenicket (about 34-mile west of the site) and the expanse between the site and the lake encompasses the Hockomock Swamp the importance of the swamp and wet area (with regard to this function) is limited

333 Contaminant Retention and Removal

Contaminants detected at the site include PCBs volatile organics semivolatile organics pesticides and metals The extent of contamination in wetland sediments and surface water will be described in Section 41 Wetlands can act to remove contaminants dissolved in surface waters or adsorbed to suspended sediments through a variety of physical and chemical processes including sediment trapping (described previously) biodegradation volatilization and uptake by plants (primarily heavy metals) The wooded swamp and the wet area are both

-17shy

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

valuable in terms of slowing the migration of PCBs off-site and reducing the concentration of volatile organics in surface waters through these mechanisms This is probably the most important function served by the wetlands at the CEC site

334 Oxygen Production

Wetlands in which large populations of submerged and aquatic vegetation exist can act to increase levels of dissolved oxygen in surface water This is possible through the process of photosynthesis which increases the aquatic habitat suitability of the wetland and can accelerate contaminant degradative processes (eg biodegradation)

Dissolved oxygen levels in the ditch draining the wet area were measured in the field by Normandeau personnel at 28 ppm levels in the canal were approximately 1 ppm (Normandeau 1985) Both of these are lower than would be expected in a pristine wetland Because the wet area contains emergent vegetation and no shrub or tree layer exists it is expected to be more effective in terms of oxygen production per unit area than the wooded swamp this might explain the higher levels observed in the ditch Given the available data however it is difficult to quantify the effectiveness of each area in terms of oxygen production Because of their small size the overall importance of both wetlands appears low compared with the Hockomock Swamp

34 SOCIOECONOMIC FUNCTIONS

Socioeconomic functions include aesthetics recreational usage educational value scientific value and historic importance The wooded swamp and the wet area are of little value in terms of aesthetics primarily because of visually observable contamination features visible in upland on-site areas such as abandoned tanks and buildings and the proximity of Route 24 In terms of recreational usage and educational value the wet area and the wooded swamp are of little value compared to the remainder of the Hockomock Swamp because of their small size According to the Bridgewater Town Clerk the Hockomock Swamp has no historic importance

35 SUMMARY OF WETLAND FUNCTIONAL ATTRIBUTES

Possibly the most important function attributable to the wet area and the wooded swamp at the CEC site is that they are acting to slow the migration rate of PCBs and to reduce concentrations of other hazardous constituents through various chemical and physical processes The importance of other functions served by the wet area and the wooded swamp is limited relative to the adjacent Hockomock Swamp Impacts associated with contamination in these areas are discussed in the following section

-18shy

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

40 EFFECTS OF CONTAMINATION

Contaminants present in surface waters and sediments may adversely affect wetland ecosystems at the CEC site The extent of contamination in these media in wetlands is described based on analytical data in Section 41 Present and future impacts to wetland ecosystems associated with contaminants are described in Section 42

41 EXTENT OF CONTAMINATION

411 Sediments

Sediment samples have been collected from the wet area the drainage ditch the drainage canal and the section of wooded swamp west of the equipment building (see Figure 2-3) Levels of contaminants in sediment samples (and surficial soil samples) collected from these areas are presented in Tables 4-1 and 4-2 Contract required detection limits are presented in Appendix B

From these tables it is evident that the wet area is the most contaminated wetland area at the CEC site High levels of volatile organics semivolatile organics and PCBs (up to 95000 ppb PCB-1242) were detected in surficial soilssediments Analysis of a sample collected from the ditch draining the wet area shows much lower levels of contamination indicating that substantial migration of contaminated soilssediments from the wet area has not yet occurred This conclusion is further supported by very low levels of contamination at SW-4 and SW-6 downstream (west) of the outfall of the ditch in the drainage canal It is interesting to note that the highest levels of sediment contamination in the drainage canal were detected upstream (east) of the site at SW-2 Because little or no flow was observed in the canal during site visits it appears possible that flow directions could be reversed under certain conditions resulting in the migration of contaminants upstream This appears unlikely however because the levels of polynuclear aromatic hydrocarbons (PAHs) detected at SW-2 were the highest overall levels in soilssediments at the site In addition no PCBs were detected at SW-2 which would have been transported (adsorbed to sediments) along with the PAHs PAHs are constituents of asphaltic tar and their presence at SW-2 is probably a result of transport via runoff from First Street

Two surficial soilsediment samples were collected from the wooded swamp west of the site These samples generally showed low levels of volatile and semivolatile organics although 4700 ppb PCB-1242 was detected at one location The extent of contamination in other portions of the wooded swamp cannot be described based on the available data

Levels of inorganics in wetland soilssediments appear low overall although some of the samples containing high levels of

-19shy

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

I I I I I I I I r 1 I r I II I I i r 1 I r 1 f 1 ) I I 1 1 ( 1 I

T A B U 4 - 1

QRGANIC OCNEfiMINAMIS DKltX-lKD IN SOIISSEDIMENIS IN THE WBT AEEA (VeQues i n ppb)

cxKJiTiuan Volatiles

SW-l(l) Sff-7f3) -SSrZSIlL SS-A(l) E-2f3) E-4(3) E-5(3) F-6(3)

benzene 15 20700J 517007 chlorobenzene 45 1630 18000 chloroform 12 mdash mdash mdash methylene chloride 32J 4700J 41700 toluene 33 2695QJ 10200J 310J 12000 trichlorofluorcnethans mdashmdash ethylbenzene 2190 mdash - 2500 tetrachloroethylene 3880 mdashmdash carbon disulfide 730K mdash total xylenes 9655

SemL-volatiles bis (2-ethylhexyl) phthalate 12000 2537 30000 20000 di-n-butyl phthalate 360 anthracene 340K mdash 200J 6101 phenol 220J 239 mdash 1200J 58aj benzoic ac id 1100J f luoranthene II 220J 270J ne^)th2dene 57K 22CJ 190 80J phenanthrene 320J 440J pyrene mdash mdash 410J 470J 12-dichlorobenzene 18K 130J 820 N-nitrosodiphenylamine 1242 1400 1700 1600J 2-inethylnaphthEdene 160 67QJ 120 24 e-trichlorophenol 265 p-chloro-m-cresol 26 diethyl phthalate 151

Pesticides PCB shy 1016 1300 PCB shy 1242 2300 1200 2200 95000 PCB shy 1254 1500 700 PCB shy 1260 780 380 dieldrin endosulfan I

S = Shallow shy = Not detected J = Estimated value K = Ccmpciund present but below listed detection limits Note Numbers in parentheses indicate sampling rcund Contract required detection limits are presented in i sendix B

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

I f ) I I r I r I ^ I i1 f raquo I i t I I I f raquo Ir I I 1 t

(TiNffrrn TPtur V o l a t i l e s

benzene chlorobenzene t - l 2 -d i c i ao roe thy lene ethylbenzene methylene c h l o r i d e to luene chlorcmethane t o t s d i ^ l e n e s chloroform t r i ch lo rof luorcmethane t e t r a c h l o r o e t h y l e n e t r i c h l o r o e t h y l e n e 1 1-d ichloroethane 2 -ch lo roe thy lv iny l e t h e r

Semi -vo la t i l e s b i s (2-ethylhejQrl) p h t h a l a t e d i - n - b u t y l p h t h a l a t e f luoranthene benzo(a) anthracene benzo(a)pyrene benzo(k) f luoran thene chrysene phenanthrene pyrene N-nitrosodiphenylamine

PesticidesPCBs PCB - 1016 PCB - 1242 PCB - 1256 PCB - 1260

CRAINAGE DITCH

3H-J11)

17J 33J 13J I U

6 4 U 13J

205J I U

mdash mdash mdash

4100J 1200J

mdash

970

TABIpound 4-2 ORGANIC OCNTAHINAmS EGTBCTED IN SOILSSEDIMENrS IN THE

CKABOGE DITCH ERABOtSl CANAL AND HOCCXD SNAMP (VeLLues in ppb)

CRAINAGE OUVINAGE ZBfJNfCE - CRAINAOE WDOCED CANAL CANAL CANAL CANAL SNAMP

SW-2Q^ SW-4a) S W - 5 r 3 ) C-9f3) sraquo-6ni

14 mdash mdash mdash mdash mdash mdash mdash mdash mdashmdash 120

bull11 mdash mdash 407 mdashmdash mdash

bull 9 4 mdash 46 2 4 3 J mdash mdash ~~

2 9K mdash mdash bull 52 mdash mdashmdash

bull mdash mdashmdash 10 mdash ^mdash mdash mdash mdash 57 mdashmdash mdash 150 mdash bull mdashmdash mdash

9SOOK mdash mdashmdash ~~ ~~ mdash

18000 mdash - mdash 69J 6000 mdash mdash mdash

mdash ^ bull bull 8400K bull11000K mdashmdash mdash ~~

bull bull bull 7000K mdashmdash mdash 29000 mdash 88J 14000 mdashmdash mdash 1107

mdash ^ bull ^ bull ^

bull bull bull mdashmdash mdash 4700

mdash mdash ~mdash

WOODED SWAMP

ss-5ai

3K7 358

3 3 J J

1 6 J J

29

~~^ 4KT 102 IK7

5K

67K

31K7

~~~

Not detected J = Estimated value K = Ccnpound present but below listed detection limits Note Numbers in parentheses indicate sairpling rcwnd Contract required detection limits are presented in ipendix B

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

organics also contained elevated levels of inorganics These included samples collected at E-5 and F-6 which contained up to 37 ppm chromium and 120 ppm lead and at SS-7S which contained 419 ppm zinc Levels elsewhere appeared to be within background levels based on comparison with other samples collected Background levels appear to be less than 30 ppm for zinc 20 ppm for lead and 10 ppm for chromium

412 Surface Water

Surface water sampling was performed at six locations (see Figure 2-3) The results of this sampling (see Table 4-3) indicate that little organic contamination of surface waters exists at the site Both toluene at 580 ppb and phenol at 150 ppb were detected at SW-5 upstream of the site however reported levels elsewhere were very low (contract required detection limits are presented in Appendix B) It is likely that volatilization and adsorption to sediment organic matter are acting to reduce the concentration of organics detected in surface water grab samples

Levels of inorganics appeared to be elevated at SW-3 in the ditch draining the wet area compared with levels at SW-4 and SW-2 Samples taken at SW-3 in 1984 and 1985 showed maximum concentrations of the following inorganics chromixim 85 ppb mercury 058 ppb cadmium 24 ppb silver 190 ppb and lead 140 ppb Levels were lower overall downstream of the site at SW-4 and lower still upstream at SW-2 However levels of some constituents (lead copper chromium and zinc) in the upstream sample were elevated above levels expected in natural waters based on experience of Jordan personnel indicating a potential source of contamination upstream other than the CEC site

42 IMPACTS TO WETLANDS

421 Ecotoxicity Assessment

As described previously contaminants were detected in wetland surface waters and sediments The levels of organic contaminants detected in surface waters (see Table 4-3) were very low and measured levels are not expected to significantly affect organisms present in wetlands at the CEC site It must be noted however that levels of organic contaminants detected in a surface water grab sample may not be representative of levels of contaminants to which organisms are actually exposed This is because volatilization will quickly reduce concentrations of volatile organics near the surface of the water while hydrophobic contaminants (eg semivolatiles and PCBs) will tend to adsorb to sediment organic matter Therefore levels in surface water just above the sediment bed sediment pore water and sediments are expected to be higher This phenomenon is observable in the CEC site data by comparing soilsediment data (see Tables 4-1 and 4-2) to surface water

-22shy

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

I r I t t I 1 r 1 I I f I I i f r t f I f f I f I f i I I I 1 I I I i

TABIE 4-3 cnraquoNic OCNTAMINANIS DETTBCTQ

(Values in ppb EN SOREACE V 1

OXERS

uoNbiTimtwr

Net Area(Pond)

Sraquo-7f3)

Drainage Ditch SW-3 a )

Drainage Canal SW-2a)

Drainage Canal SW-4fl)

Drainage Canal sw-sni

Drainage Canal sw-en^

Volati les 112-trichloroethan9 chlorofom toluene trichloroethylene

43J 26J 33J 580

2K

fiemj -voTLatiles Ehenol b i s (2-ethylhexyl) phthalate 7Kr 7K

150 13J

Note Numbers in parentheses indicate saipl ing round Contract required detection l imits are presented in Appendix B

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

data (see Table 4-3) Levels of contaminants detected in surface water grab samples may not represent exposure concentrations to aquatic organisms living in sediments (ie Oligochaeta Odonata Diptera Crustacea) or existing near sediments in the benthic zone and ingesting benthic invertebrates (ie Ictaluridae) (see Section 222)

Contaminants in sediments can be made available to aquatic biota in two ways direct contact with contaminated sediments and release of contaminants to surface water and subsequent contact with contaminated surface water The majority of ecotoxicity test data relate adverse effects to contaminant concentrations in surface water Levels of organic contaminants in sediments generally will not be identical to those in surface waters because contaminants will preferentially partition into water or sediments depending on their chemical and physical properties However it is safe to assume that some level of contamination in surface waters (at least near the sediment bed) will exist as a result of release from contaminated sediments Surface water ecotoxicity data for some of the organic contaminants detected in sediments at the CEC site are presented in Table 4-4 Although some of the data are for organisms which may not exist at the site these organisms were chosen because they are phylogenetically similar to those expected in wetlands at the site Two types of ecotoxicity data are presented in Table 4-4 the results of ecotoxicity testing for the species listed and Ambient Water Quality Criteria (AWQC) (guidelines for the protection of all freshwater aquatic life established by EPA using a wide range of ecotoxicity test results) The maximum concentrations of organic contaminants detected in sediments are also shown for comparison in Table 4-4

From the table it can be seen that acute and chronic toxicity to wetland organisms may be occurring as a result of exposure to benzene chlorobenzene bis(2-ethylhexyl)phthalate and PCBs if these organisms are in fact being exposed to the concentrations shown Actual PCB and bis(2-ethylhexyl)phthalate exposure concentrations may be lower than those levels reported for sediments due to their preferential partitioning onto sediments as indicated by high log octanol-water partitioning coefficients (K ) and low aqueous soliibilities Benzene and chlorobenzene however have low K values and high aqueous solubilities indicating that their exposure concentrations may be higher than levels reported for sediments In general organisms living in or near the sediment bed will be exposed to higher levels of contamination than those which do not

Levels of inorganics in surface waters may also result in acute andor chronic toxicity to aquatic organisms as concentrations of some inorganics exceed AWQC (see Table 4-5) It appears that chromium copper lead and silver in surface waters may result

-24shy

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

I I I I f I I I I I t I I J f I I 1 f 1 r I t 1 r I I I I I 1 f 1 I raquo t laquo

TABLE 4 - 4 BOOTOXICnY TEST RESUUES AND AMBIENT WATER QUALTIY

CJHTERIA FOR SElpoundCTED OONTAMINANIS DETECTED IN WETLANDS AT THE CEC SITE

OCNTAMDlAMr

Benzene

ChlortDbenzene

Methylene Chloride

Toluene

Trans-12shydichloroethylene

Trichloroethylene

SPECIES

Rainbow t r o u t SaOmo q a i r d n e r l

F r e s h w a t e r F i s h ^

Cladooeran Daphnia magna

Fathead minncw Pimephales prornelas

CLadooeran Daphnia magna

Fathead minncw Pinephales prornelas

Cladooeran tephnia pulex

fathead minncw Pimephales promelcis

K t r a J V

Decreased Reproducticn

BOOTOXCnY TEST RESUIITS MEAN ACUTE MEAN CHRONIC

VAIUE (ua1)

386000

VAUJE (ua1)

5300

ACUTE(xxU

5300deg

AW3C CHRONIC

(ual)

MAXIMUM OONCTNTRATION IN SEDIMENTS

(yxfVn)

51700

Letheugy 25000 10000 250deg 18000

Lethality 224000 41700

Lethality 193000 41700

LethalityDecreased Ri^roduction

313000 12700 17500 26950

Decreased Ri^roducticn

108000 lt2800 358

lethality 45000 45000 21900 150

Loss of Equilibrium

40700 21900 45000 21900^ 150

= Based on tests of individuzd species ^ = Ambient Water Quidity Ctiteria for the protection of all freshwater aquatic life = This v a l v B is not representative of the AWQC but represents the Icwest concentration available from the literature = Test species unkncwn

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

I I I 1 I I I I I 1 f I I I t 1 I I f I I I I laquo raquo I I r raquo laquo raquo I i I

TABIE 4 - 4 ( c o n t i n u e d )

BOOTOXICnY TEST HESUiaS AND AMBIENT WATER QUALTIY ORTTEEOA FOR SEIECIED CXWTAMINANIS EETECTED IN WBTIANDS AT THE CEC SITE

MAXIMUM EOOIDXdTY TEST RESULTS AWQC^ OCWCEMTRATION

MEAN ACUTE MEAN CHHCXnC ACUTE CHRONIC IN SEDIMEMS OOOTAMINANr SPECIES EFFECT VALUE (vxr1) VALUE f u g l ) (val) (ua1) fug togt

b i s (2-e thylhexyl) midge (order Diptera) Lethality 18000 30000 p h t h a l a t e

Cladooeran Decreased 11100 30000 Daphnia magna reproducticn

PCBs Channel catfish Lethality 100 0014 95000 Ictaluris punctatua

Invertebrate species Lethality 0014 95000

= Clement Associates Inc Arlington Virginia Chaniceil Hiysiceil and Biological Pmperties of Ccnpounds Present at Hazeuxlous Waste Sites Final Report 1985

= Ambient Water Quality Criteria for the protection of all freshwater aquatic life = This value is not r^resentative of the AWQC but r^resents the Icwest ccnoentraticn available frcm the literature = Test species unkncwn

Note Contract required detection limits are presented in Appendix B

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

I i I 1 f 1 I I f I I I I I f I f r ) I ) f 1 f I f 1 f I I 1 f ) I 1 I 1

TABIpound 4-5 MAXIMUM IpoundVEIS OF INORGANIC OMISTITUENIS IN SURFACE WATERS

AND AMBIENT WATER QUALTTX CRITERIA (AWQC)

GONSTnUEMT

Aluminum AntlmoTY Arsenic Barium Beryllium cadmium Chranium nnhnlt Copper Iron Lead Manganese Mercury Nickel Silver Thedlium Vanadium Zinc

MAXIMUM OOKENIRATION

(ua1)

1900 lt6 34 57 lt1

24J 85 28 447

5500 140

84607 058 115

190J lt2

178J 150

lOCATION OF MAXIMUM

SW-2(1) SW-234(2)

SW-3(2) Sraquo-3(l)

SW-234(2) SW-3(2) SW-3(1) SW-3 (2) SW-3 (2) SW-2(1) SW-3 (2) SW-3(2) SW-3 (2) SW-3(2) SW-3(1)

All locations SW-3(2) SW-2(1)

AWQC 1

ACUTE (W1)

N a 9000

360(III)850(V)

130j 39deg

16 (VI)

TJ 18deg ^ 82deg NC

^bullB^ 1400

3Sgt

CHRONIC fucf1)

^a 1600

190(III)48(V)

raquo a 5-^ 11deg

11 (VI)

^K1000^ 32deg NC

bull gt 012^ 40 NC 47

Criteria not established Value presented is the Lowest Observed Effect Level (lOEL)

Assuming a hardness of lQQmj1 as CaOO

degIrcn may be found in swamp waters at several ppm with no adverse effects

NC = No Criteria established

Note Nunter in parentheses under location of Maxinum indicates the sampling round Contract required detection limits are presented in i^ipendix B

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

in acute and chronic toxicity concentrations of cadmium mercury nickel and zinc may result in chronic toxicity It should be noted that the maximim concentrations of these contaminants were reported for sample location SW-3 collected from the ditch draining the wet area Levels downstream (west) of the site were lower and lower still upstream at SW-2 However levels of some constituents in these samples also exceeded AWQC (lead copper chromium zinc and silver) indicating a potential source of inorganic contamination upstream other than the CEC site

Acute and chronic toxicity may result in a decrease in aquatic organism population densities and subsequent changes in wetland ecosystems as a result of a paucity of food sources The presence of stressed vegetation (sparse lower growth habit) south of the tank farm sxibstantiates the contention that some acute impacts are occurring In these areas no aquatic organisms are expected because they are generally much more sensitive to contaminants than plants Bioaccumulation and biomagnification of PCBs semivolatiles and inorganics from wet area sediments in the food chain may be resulting in toxicity to higher trophic level organisms

422 Future Impacts

Assuming no remedial action is implemented at the CEC site organisms present in wetlands (primarily the wet area) will continue to be exposed to volatile organics semivolatile organics PCBs and inorganics Levels of volatile organics may decrease over time while semivolatiles PCBs and inorganics are expected to persist A concern is that mobilization of PCBs adsorbed onto sediments in the wet area into the wooded swamp may occur in the future This would result in an increase in the extent of effects on wetland organisms because of the high degree of toxicity of PCBs even at low levels (see Table 4-4) This could have an impact on wetland ecosystems because elimination of the more sensitive lower trophic level organisms would result in changes in the types of predatory organisms which feed on them Furthermore bioaccumulation and biomagnification of PCBs semivolatiles and inorganics in the food chain may result in impacts to higher trophic level organisms

-28shy

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

50 WETLANDS PROTECTION REGULATIONS

A detailed evaluation of compliance of remedial alternatives with applicable regulations will be performed in the FS A summary of applicable wetlands protection regulations is presented here for informational purposes

According to the preamble of the NCP (40 CFR Part 300 Federal Register November 20 1985) CERCLA actions will consider federal state and local environmental standards These include Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands) as implemented by EPAs Office of Emergency and Remedial Response August 6 1985 Policy on Floodplains and Wetlands Assessments for CERCLA Actions Executive Order 11988 states that federal agencies shall take action to reduce the risk of flood loss to minimize the impact of floods on human safety health and welfare and to restore and preserve the natural and beneficial values served by floodplains Executive Order 11990 states that federal agencies shall minimize the destruction loss or degradation of wetlands and preserve and enhance the natural and beneficial values of wetlands in carrying out the agencys responsibilities

The Superfund Amendments and Reauthorization Act of 1986 (SARA) also affects work in or near wetlands Under the act on-site remedial actions must at least attain any promulgated state requirement which is more stringent than any federal requirement Therefore the requirements of the Massachusetts Wetlands Protection Act (Massachusetts General Laws Chapter 131 Section 40) must be met however state permits are not required Additionally SARA requires remedial actions to at least attain water quality criteria under the Clean Water Act This would apply to wetland surface waters at the CEC site

-29shy

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

60 SUMMARY AND CONCLUSIONS

Two wetland areas have been identified at the CEC site the wet area and the wooded swamp While both wetlands possess some value relative to hydrologic functions habitat functions and water quality functions their importance is limited compared to that of the adjacent Hockomock Swamp Except for dead vegetation in the wet area no other observable manifestations of stress have been noted It should be noted however that a potential for acute andor chronic toxicity to aquatic organisms (which are generally more sensitive than aquatic vegetation) exists because levels of cadmium chromium copper lead mercury nickel silver and zinc in surface waters exceed AWQC and levels of PCBs and possibly benzene chlorobenzene and bis(2-ethylhexyl)phthalate in soils and sediments were high in the contaminated wet area Because the wooded swamp (excluding the drainage canal) contains low levels of contamination few effects are expected However it appears possible that mobilization of PCBs from the wet area into the wooded swamp could occur in the future which could result in adverse impacts there

Alternatives proposed for site cleanup will be evaluated in terms of their adverse and beneficial effects on wetlands at the site in the FS If adverse impacts are expected mitigative measures will be developed The conformance of alternatives with applicable or relevant and appropriate standards criteria and guidance as well as other environmental laws for the protection of wetlands also will be evaluated

-30shy

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

APPENDIX A

REFERENCES

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

APPENDIX A REFERENCES

Adamus PR Center for Natural Areas Gardiner Maine A Method for Wetland Functional Assessment Vols I and II Report Nos FHWS-IP-82-23 and FHWA-IP-82-24 Federal Highway Administration March 1983

Callahan MA et al Water-related Environmental Fate ofPriority Pollutants Vols I and II EPA 4404-79-029a-029b December 1979

129 and

Camp Dresser and McKee Inc Remedial Action Master Plan Cannons Engineering Corporation Site 1983

Chapman PM Sediment Quality Criteria from the Sediment Quality Triad An Example Environmental ToxicologyChemistry Vol 5 pp 947-964 1986

and

Cowardin LM V Carter FC Golet and ET LaRoe Classification of Wetlands and Deepwater Habitats of the United States FWSOBS-7931 US Fish and Wildlife Service Washington DC 1979

DeGraaf RM and DD Rudis Amphibians and Reptiles of New England University of Massachusetts Press Amherst 1983

Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Town of Bridgewater Massachusetts May 1982

Godin AJ Wild Mammals of New England (field guide edition) DeLorme Publishing CoGlobe Pequot Press Chester Connecticut 1983

Normandeau Associates Incorporated Bedford New Hampshire Baseline Investigations of Wetlands and Wetland Benefits at the Cannons Engineering Corporation Superfund Site Prepared for EC Jordan Co Report No R-445 October 1985

Reed PB Jr 1986 Wetland Plant List Northeast Region National Wetlands Inventory US Fish and Wildlife Service St Petersburg Florida WELUT-86W1301 May 1986

Reppert RT W Sigleo E Stakhiv L Messman and C Meyers US Army Corps of Engineers Institute for Water Resources Wetland Values Concepts and Methods for Wetlands Evaluation IWR Research Report 79-Rl February 1979

APPENDIX A (Continued) REFERENCES

US Environmental Protection Agency Environmental Photographic Information Center Aerial photographs of the Cannons Engineering Corporation site in Bridgewater Massachusetts photographs dated November 1964 August 1971 February 1974 April 1980 and October 1982

US Fish and Wildlife Service National Wetlands Inventory Map for the Taunton Massachusetts Quadrangle aerial photography performed April 1977

US Geological Survey Topographic map Taunton Massachusetts Quadrangle 75-minute series 1978

APPENDIX B

HAZARDOUS SUBSTANCE LIST AND

CONTRACT REQUIRED DETECTION LIMITS

HSL CONTRACT REQUIRED DETECTION LIMITS

UOLATILES

chloronethane bronoMethane vinyl chloride chloroethane nethylene chloride acetone carbon disulfide 1 1-dichloroethene 1 )-dichloroethane trans-l 2-dichloroethene chloroform 1 2-dichloroethflne 2-butanone 1 1 1-trichloroethane carbon tetrachloride vinyl acetate bronodichloromethane 1 1 2 2-tetrachloroethane 12-dichloropropane trans-l 3-dichloropropene trichloroethene dibromochloromethane 112-trichloroethane benzene cis-13-dichloropropene 2-chloroethyl vinyl ether bromoform 2-hexanone 4-methyl-2-pentanone tetrachloroethene toluene chlorobenzene ethyl benzene styrene total xylenes

SEMI-UOLATILES

N-nitrosodimethylamine phenol aniline bi5lt2-chloroethyl )ether 2-chlorophenol 1 3-dichlorobenzene 1 4-dichlorobenzene benzyl alcohol 1 2-dichlorobenzene

WATER (UQI)

10 10 10 10 5 10 5 5 5 5 5 5 10 5 5 10 5 5 5 E 5 5 5 E E 10 E 10 10 E E B E E B

10 10 10 10 10 10 10 10 10

SLUDGESOIL (ugkp)

10 10 10 10 5 10 5 B B B B B 10 B B 10 B B B B B B B S B 10 B 10 10 E B B B B B

330 330 330 330 330 330 330 330 330

Detection limits for soilsludge are based on wet weight

B-1

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (ug1) SLUDGESOIL (ugkg)

2-nethylphenol bi5(2-chioroi5opropyl )ether 4-methylphenol N-nitrosodipropyl amine hexachloroethane nitrobenzene isophorone 2-nitrophenol 2 4-dimethylphenol benzoic acid bis(2-chloroethoxy )methane 2 4-dichlorophenol 1 2 4-trichlorobenzene naphthalene 4-chloroaniline hexacholorobutadiene 4-chioro-3-methylphenol 2-methylnaphthalene hexachlorocyclopentadiene 2 4 B-trichlorophenol 2 4 B-trichlorophenol 2-chloronaphthalene 2-nitroaniline dimethyl phthalate acenaphthylene 3-nitroaniiine acenaphthene 24-dinitrophenol 4-nitrophenol dibenzofuran 2 4-dinitrotoluene 2 6-dinitrotoluene diethylphthalate 4-chlorophenyl phenyl ether fluorene 4-nitroaniline 4 6-dinitro-2-methylphenol N-nitrosodiphenylamine 4-bromophenyl phenyl ether hexachlorobenzene pentachlorophenol phenanthrene anthracene di-n-butyl phthalate fluoranthene benzidine pyrene butyl benzyl phthalate 33-dichlorobenzidine benzo(a )anthracene

10 10 10 10 10 10 10 10 10 E0 10 10 10 10 10 10 10 10 10 10 E0 10 B0 10 10 B0 10 B0 B0 10 10 10 10 10 10 50 50 10 10 10 E0 10 10 10 10 50 10 10 20 10

550 550 330 330 550 330 350 550 330 1E00 350 350 550 550 330 350 330 330 330 350 1G00 350 1E00 550 330 1600 330 1600 1600 330 330 350 330 330 330 1600 1600 330 350 550 1600 330 330 330 330 1600 330 330 660 330

Detection limits for soilsludge are based on wet weight

B-2

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER ltugl) SLUDGESOIL lt ugkg)

biElt2-e thy lhexyl p h t h a l a t e chrysene di-n-octyl phthalate benzoCb )fluorantbene benzo(k )fluoranthene benzo(a )pyrene indeno(1 2 5-cd )pyrene dibenzo(ah )anthracene benzo(g h i )perylene

PESTICIDESPCB

alpha-BHC beta-BHC delta-BHC gamma-BHC (lindane) heptachlor aldrin heptachlor epoxide endosulfan I dieldrin 44-DDE endrin endosulfan II 44-DDD endrin aldehyde endosulfan sulfate 44-DDT endrin ketone methoxychlor chlordane toxaphene AROCLOR-1016 AROCLOR-1221 AROCLOR-1232 AROCLOR-1242 AROCLOR-1248 AR0CL0R-12B4 AROCLOR-1260

INORGANICS

aluminum antimony arsenic barium beryllium cadmium

10 10 10 10 10 10 10 10 10

0B

0B

0E

0E

0E

0B

0B

0S 010 010 010 010 010 010 010 010 010 0 0 10 05 0B 05 05 05 1 0 1 0

200 60 10 200 5 B

350 550 550 550 550 550 550 550 550

20 20 20 20 20 20 20 0

4 0 4 0 4 0 40 40 40 40 40 40 200 200 400 200 200 200 200 200 400 400

20000 6000 1000 20000 500 B00

Detection limits for soilsludge are based on wet weight

B-3

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (UQ1) SLUDGESOIL ltugkg)

calcium chromium cobalt copper iron lead magnesium manganese mercury nickel potassium selenium silver sodium thallium tin vanadium zinc cyanide

5000 10 50 25 100 5

5000 15 02 40 5000 5 10

5000 10 40 50 20 10

500000 1000 5000 2500 10000 500

500000 1500 20 4000 500000 500 1000

500000 1000 4000 5000 2000 1000

B-4

APPENDIX B

HAZARDOUS SUBSTANCE LIST AND

CONTRACT REQUIRED DETECTION LIMITS

HSL CONTRACT REQUIRED DETECTION LIMITS

UOLATILES

chloronethane bronoMethane vinyl chloride chloroethane nethylene chloride acetone carbon disulfide 1 1-dichloroethene 1 )-dichloroethane trans-l 2-dichloroethene chloroform 1 2-dichloroethflne 2-butanone 1 1 1-trichloroethane carbon tetrachloride vinyl acetate bronodichloromethane 1 1 2 2-tetrachloroethane 12-dichloropropane trans-l 3-dichloropropene trichloroethene dibromochloromethane 112-trichloroethane benzene cis-13-dichloropropene 2-chloroethyl vinyl ether bromoform 2-hexanone 4-methyl-2-pentanone tetrachloroethene toluene chlorobenzene ethyl benzene styrene total xylenes

SEMI-UOLATILES

N-nitrosodimethylamine phenol aniline bi5lt2-chloroethyl )ether 2-chlorophenol 1 3-dichlorobenzene 1 4-dichlorobenzene benzyl alcohol 1 2-dichlorobenzene

WATER (UQI)

10 10 10 10 5 10 5 5 5 5 5 5 10 5 5 10 5 5 5 E 5 5 5 E E 10 E 10 10 E E B E E B

10 10 10 10 10 10 10 10 10

SLUDGESOIL (ugkp)

10 10 10 10 5 10 5 B B B B B 10 B B 10 B B B B B B B S B 10 B 10 10 E B B B B B

330 330 330 330 330 330 330 330 330

Detection limits for soilsludge are based on wet weight

B-1

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (ug1) SLUDGESOIL (ugkg)

2-nethylphenol bi5(2-chioroi5opropyl )ether 4-methylphenol N-nitrosodipropyl amine hexachloroethane nitrobenzene isophorone 2-nitrophenol 2 4-dimethylphenol benzoic acid bis(2-chloroethoxy )methane 2 4-dichlorophenol 1 2 4-trichlorobenzene naphthalene 4-chloroaniline hexacholorobutadiene 4-chioro-3-methylphenol 2-methylnaphthalene hexachlorocyclopentadiene 2 4 B-trichlorophenol 2 4 B-trichlorophenol 2-chloronaphthalene 2-nitroaniline dimethyl phthalate acenaphthylene 3-nitroaniiine acenaphthene 24-dinitrophenol 4-nitrophenol dibenzofuran 2 4-dinitrotoluene 2 6-dinitrotoluene diethylphthalate 4-chlorophenyl phenyl ether fluorene 4-nitroaniline 4 6-dinitro-2-methylphenol N-nitrosodiphenylamine 4-bromophenyl phenyl ether hexachlorobenzene pentachlorophenol phenanthrene anthracene di-n-butyl phthalate fluoranthene benzidine pyrene butyl benzyl phthalate 33-dichlorobenzidine benzo(a )anthracene

10 10 10 10 10 10 10 10 10 E0 10 10 10 10 10 10 10 10 10 10 E0 10 B0 10 10 B0 10 B0 B0 10 10 10 10 10 10 50 50 10 10 10 E0 10 10 10 10 50 10 10 20 10

550 550 330 330 550 330 350 550 330 1E00 350 350 550 550 330 350 330 330 330 350 1G00 350 1E00 550 330 1600 330 1600 1600 330 330 350 330 330 330 1600 1600 330 350 550 1600 330 330 330 330 1600 330 330 660 330

Detection limits for soilsludge are based on wet weight

B-2

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER ltugl) SLUDGESOIL lt ugkg)

biElt2-e thy lhexyl p h t h a l a t e chrysene di-n-octyl phthalate benzoCb )fluorantbene benzo(k )fluoranthene benzo(a )pyrene indeno(1 2 5-cd )pyrene dibenzo(ah )anthracene benzo(g h i )perylene

PESTICIDESPCB

alpha-BHC beta-BHC delta-BHC gamma-BHC (lindane) heptachlor aldrin heptachlor epoxide endosulfan I dieldrin 44-DDE endrin endosulfan II 44-DDD endrin aldehyde endosulfan sulfate 44-DDT endrin ketone methoxychlor chlordane toxaphene AROCLOR-1016 AROCLOR-1221 AROCLOR-1232 AROCLOR-1242 AROCLOR-1248 AR0CL0R-12B4 AROCLOR-1260

INORGANICS

aluminum antimony arsenic barium beryllium cadmium

10 10 10 10 10 10 10 10 10

0B

0B

0E

0E

0E

0B

0B

0S 010 010 010 010 010 010 010 010 010 0 0 10 05 0B 05 05 05 1 0 1 0

200 60 10 200 5 B

350 550 550 550 550 550 550 550 550

20 20 20 20 20 20 20 0

4 0 4 0 4 0 40 40 40 40 40 40 200 200 400 200 200 200 200 200 400 400

20000 6000 1000 20000 500 B00

Detection limits for soilsludge are based on wet weight

B-3

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (UQ1) SLUDGESOIL ltugkg)

calcium chromium cobalt copper iron lead magnesium manganese mercury nickel potassium selenium silver sodium thallium tin vanadium zinc cyanide

5000 10 50 25 100 5

5000 15 02 40 5000 5 10

5000 10 40 50 20 10

500000 1000 5000 2500 10000 500

500000 1500 20 4000 500000 500 1000

500000 1000 4000 5000 2000 1000

B-4

HSL CONTRACT REQUIRED DETECTION LIMITS

UOLATILES

chloronethane bronoMethane vinyl chloride chloroethane nethylene chloride acetone carbon disulfide 1 1-dichloroethene 1 )-dichloroethane trans-l 2-dichloroethene chloroform 1 2-dichloroethflne 2-butanone 1 1 1-trichloroethane carbon tetrachloride vinyl acetate bronodichloromethane 1 1 2 2-tetrachloroethane 12-dichloropropane trans-l 3-dichloropropene trichloroethene dibromochloromethane 112-trichloroethane benzene cis-13-dichloropropene 2-chloroethyl vinyl ether bromoform 2-hexanone 4-methyl-2-pentanone tetrachloroethene toluene chlorobenzene ethyl benzene styrene total xylenes

SEMI-UOLATILES

N-nitrosodimethylamine phenol aniline bi5lt2-chloroethyl )ether 2-chlorophenol 1 3-dichlorobenzene 1 4-dichlorobenzene benzyl alcohol 1 2-dichlorobenzene

WATER (UQI)

10 10 10 10 5 10 5 5 5 5 5 5 10 5 5 10 5 5 5 E 5 5 5 E E 10 E 10 10 E E B E E B

10 10 10 10 10 10 10 10 10

SLUDGESOIL (ugkp)

10 10 10 10 5 10 5 B B B B B 10 B B 10 B B B B B B B S B 10 B 10 10 E B B B B B

330 330 330 330 330 330 330 330 330

Detection limits for soilsludge are based on wet weight

B-1

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (ug1) SLUDGESOIL (ugkg)

2-nethylphenol bi5(2-chioroi5opropyl )ether 4-methylphenol N-nitrosodipropyl amine hexachloroethane nitrobenzene isophorone 2-nitrophenol 2 4-dimethylphenol benzoic acid bis(2-chloroethoxy )methane 2 4-dichlorophenol 1 2 4-trichlorobenzene naphthalene 4-chloroaniline hexacholorobutadiene 4-chioro-3-methylphenol 2-methylnaphthalene hexachlorocyclopentadiene 2 4 B-trichlorophenol 2 4 B-trichlorophenol 2-chloronaphthalene 2-nitroaniline dimethyl phthalate acenaphthylene 3-nitroaniiine acenaphthene 24-dinitrophenol 4-nitrophenol dibenzofuran 2 4-dinitrotoluene 2 6-dinitrotoluene diethylphthalate 4-chlorophenyl phenyl ether fluorene 4-nitroaniline 4 6-dinitro-2-methylphenol N-nitrosodiphenylamine 4-bromophenyl phenyl ether hexachlorobenzene pentachlorophenol phenanthrene anthracene di-n-butyl phthalate fluoranthene benzidine pyrene butyl benzyl phthalate 33-dichlorobenzidine benzo(a )anthracene

10 10 10 10 10 10 10 10 10 E0 10 10 10 10 10 10 10 10 10 10 E0 10 B0 10 10 B0 10 B0 B0 10 10 10 10 10 10 50 50 10 10 10 E0 10 10 10 10 50 10 10 20 10

550 550 330 330 550 330 350 550 330 1E00 350 350 550 550 330 350 330 330 330 350 1G00 350 1E00 550 330 1600 330 1600 1600 330 330 350 330 330 330 1600 1600 330 350 550 1600 330 330 330 330 1600 330 330 660 330

Detection limits for soilsludge are based on wet weight

B-2

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER ltugl) SLUDGESOIL lt ugkg)

biElt2-e thy lhexyl p h t h a l a t e chrysene di-n-octyl phthalate benzoCb )fluorantbene benzo(k )fluoranthene benzo(a )pyrene indeno(1 2 5-cd )pyrene dibenzo(ah )anthracene benzo(g h i )perylene

PESTICIDESPCB

alpha-BHC beta-BHC delta-BHC gamma-BHC (lindane) heptachlor aldrin heptachlor epoxide endosulfan I dieldrin 44-DDE endrin endosulfan II 44-DDD endrin aldehyde endosulfan sulfate 44-DDT endrin ketone methoxychlor chlordane toxaphene AROCLOR-1016 AROCLOR-1221 AROCLOR-1232 AROCLOR-1242 AROCLOR-1248 AR0CL0R-12B4 AROCLOR-1260

INORGANICS

aluminum antimony arsenic barium beryllium cadmium

10 10 10 10 10 10 10 10 10

0B

0B

0E

0E

0E

0B

0B

0S 010 010 010 010 010 010 010 010 010 0 0 10 05 0B 05 05 05 1 0 1 0

200 60 10 200 5 B

350 550 550 550 550 550 550 550 550

20 20 20 20 20 20 20 0

4 0 4 0 4 0 40 40 40 40 40 40 200 200 400 200 200 200 200 200 400 400

20000 6000 1000 20000 500 B00

Detection limits for soilsludge are based on wet weight

B-3

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (UQ1) SLUDGESOIL ltugkg)

calcium chromium cobalt copper iron lead magnesium manganese mercury nickel potassium selenium silver sodium thallium tin vanadium zinc cyanide

5000 10 50 25 100 5

5000 15 02 40 5000 5 10

5000 10 40 50 20 10

500000 1000 5000 2500 10000 500

500000 1500 20 4000 500000 500 1000

500000 1000 4000 5000 2000 1000

B-4

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (ug1) SLUDGESOIL (ugkg)

2-nethylphenol bi5(2-chioroi5opropyl )ether 4-methylphenol N-nitrosodipropyl amine hexachloroethane nitrobenzene isophorone 2-nitrophenol 2 4-dimethylphenol benzoic acid bis(2-chloroethoxy )methane 2 4-dichlorophenol 1 2 4-trichlorobenzene naphthalene 4-chloroaniline hexacholorobutadiene 4-chioro-3-methylphenol 2-methylnaphthalene hexachlorocyclopentadiene 2 4 B-trichlorophenol 2 4 B-trichlorophenol 2-chloronaphthalene 2-nitroaniline dimethyl phthalate acenaphthylene 3-nitroaniiine acenaphthene 24-dinitrophenol 4-nitrophenol dibenzofuran 2 4-dinitrotoluene 2 6-dinitrotoluene diethylphthalate 4-chlorophenyl phenyl ether fluorene 4-nitroaniline 4 6-dinitro-2-methylphenol N-nitrosodiphenylamine 4-bromophenyl phenyl ether hexachlorobenzene pentachlorophenol phenanthrene anthracene di-n-butyl phthalate fluoranthene benzidine pyrene butyl benzyl phthalate 33-dichlorobenzidine benzo(a )anthracene

10 10 10 10 10 10 10 10 10 E0 10 10 10 10 10 10 10 10 10 10 E0 10 B0 10 10 B0 10 B0 B0 10 10 10 10 10 10 50 50 10 10 10 E0 10 10 10 10 50 10 10 20 10

550 550 330 330 550 330 350 550 330 1E00 350 350 550 550 330 350 330 330 330 350 1G00 350 1E00 550 330 1600 330 1600 1600 330 330 350 330 330 330 1600 1600 330 350 550 1600 330 330 330 330 1600 330 330 660 330

Detection limits for soilsludge are based on wet weight

B-2

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER ltugl) SLUDGESOIL lt ugkg)

biElt2-e thy lhexyl p h t h a l a t e chrysene di-n-octyl phthalate benzoCb )fluorantbene benzo(k )fluoranthene benzo(a )pyrene indeno(1 2 5-cd )pyrene dibenzo(ah )anthracene benzo(g h i )perylene

PESTICIDESPCB

alpha-BHC beta-BHC delta-BHC gamma-BHC (lindane) heptachlor aldrin heptachlor epoxide endosulfan I dieldrin 44-DDE endrin endosulfan II 44-DDD endrin aldehyde endosulfan sulfate 44-DDT endrin ketone methoxychlor chlordane toxaphene AROCLOR-1016 AROCLOR-1221 AROCLOR-1232 AROCLOR-1242 AROCLOR-1248 AR0CL0R-12B4 AROCLOR-1260

INORGANICS

aluminum antimony arsenic barium beryllium cadmium

10 10 10 10 10 10 10 10 10

0B

0B

0E

0E

0E

0B

0B

0S 010 010 010 010 010 010 010 010 010 0 0 10 05 0B 05 05 05 1 0 1 0

200 60 10 200 5 B

350 550 550 550 550 550 550 550 550

20 20 20 20 20 20 20 0

4 0 4 0 4 0 40 40 40 40 40 40 200 200 400 200 200 200 200 200 400 400

20000 6000 1000 20000 500 B00

Detection limits for soilsludge are based on wet weight

B-3

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (UQ1) SLUDGESOIL ltugkg)

calcium chromium cobalt copper iron lead magnesium manganese mercury nickel potassium selenium silver sodium thallium tin vanadium zinc cyanide

5000 10 50 25 100 5

5000 15 02 40 5000 5 10

5000 10 40 50 20 10

500000 1000 5000 2500 10000 500

500000 1500 20 4000 500000 500 1000

500000 1000 4000 5000 2000 1000

B-4

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER ltugl) SLUDGESOIL lt ugkg)

biElt2-e thy lhexyl p h t h a l a t e chrysene di-n-octyl phthalate benzoCb )fluorantbene benzo(k )fluoranthene benzo(a )pyrene indeno(1 2 5-cd )pyrene dibenzo(ah )anthracene benzo(g h i )perylene

PESTICIDESPCB

alpha-BHC beta-BHC delta-BHC gamma-BHC (lindane) heptachlor aldrin heptachlor epoxide endosulfan I dieldrin 44-DDE endrin endosulfan II 44-DDD endrin aldehyde endosulfan sulfate 44-DDT endrin ketone methoxychlor chlordane toxaphene AROCLOR-1016 AROCLOR-1221 AROCLOR-1232 AROCLOR-1242 AROCLOR-1248 AR0CL0R-12B4 AROCLOR-1260

INORGANICS

aluminum antimony arsenic barium beryllium cadmium

10 10 10 10 10 10 10 10 10

0B

0B

0E

0E

0E

0B

0B

0S 010 010 010 010 010 010 010 010 010 0 0 10 05 0B 05 05 05 1 0 1 0

200 60 10 200 5 B

350 550 550 550 550 550 550 550 550

20 20 20 20 20 20 20 0

4 0 4 0 4 0 40 40 40 40 40 40 200 200 400 200 200 200 200 200 400 400

20000 6000 1000 20000 500 B00

Detection limits for soilsludge are based on wet weight

B-3

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (UQ1) SLUDGESOIL ltugkg)

calcium chromium cobalt copper iron lead magnesium manganese mercury nickel potassium selenium silver sodium thallium tin vanadium zinc cyanide

5000 10 50 25 100 5

5000 15 02 40 5000 5 10

5000 10 40 50 20 10

500000 1000 5000 2500 10000 500

500000 1500 20 4000 500000 500 1000

500000 1000 4000 5000 2000 1000

B-4

HSL CONTRACT REQUIRED DETECTION LIMITS

WATER (UQ1) SLUDGESOIL ltugkg)

calcium chromium cobalt copper iron lead magnesium manganese mercury nickel potassium selenium silver sodium thallium tin vanadium zinc cyanide

5000 10 50 25 100 5

5000 15 02 40 5000 5 10

5000 10 40 50 20 10

500000 1000 5000 2500 10000 500

500000 1500 20 4000 500000 500 1000

500000 1000 4000 5000 2000 1000

B-4