dupont- newport site reviewthe dupont-newport superfund site is located south of newport, delaware,...

DRAFT

DuPont- Newport Site Review

- Review of Ecological Concerns -

Prepared For:

Mr. Randy SturgeonU.S. Environmental Protection Agency, Region III

841 Chestnut StreetPhiladelphia, Pennsylvania 19107

Prepared By:

Dynamac Corporation53 Darby Road

Paoli, Pennsylvania 19301

Contract No. 68-W9-0005 (TES VIII)Work Assignment No. R03021

Project No. P041-C01December 31, 1991

Prepared By: , Reviewed By

Carol Macbeth Jan CuiteonSenior Toxicologist Manager jof Environmental

Sciences Division

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DRAFT DuPont Newport Site Review: Review of Ecological Concerns

TABLE OF CONTENTS

CHAPTER 1: INTRODUCTION

1.1 Report Obj ectives....................................... 11.2 Scope of Work........................................... 1

1.2.1 Components of a Proper Ecological Assessment....... 31.3 Site Location and Description........................... 31.4 Site History............................................ 3

CHAPTER 2: SUMMARY OP PREVIOUS SITE INVESTIGATIONS

2.1 Past Site Investigation Reports......................... 6

CHAPTER 3: CONTAMINANTS OF CONCERN

3.1 Introduction............................................ 83.2 General Discussion of Contaminants of Concern

Importance and Definition............................... 83.3 Contaminant of Concern Selection Rationale.............. 8

3.3.1 Cadmium.......................................... 93.3.2 Chromium......................................... 103.3.3 TCE, PCE, PAH.................................... 11

3.4 Conclusions............................................. 11

CHAPTER 4: REFERENCE CONDITION

4.1 Introduction............................................ 124.2 Use of Contaminated Site RS15 As Reference Condition.... 124.3 Use of RS15 as Reference condition for Biotic

Relative Abundance...................................... 154.4 Combined Use of RS15 and AS12 as Reference Condition in the

Sediment Triad Analysis................................. 154.5 Design Flaw in Sediment Triad Analysis.................. 164.6 Sediment Triad Analysis Interpretation.................. 174.7 Conclusions............................................. 18

CHAPTER 5: SITE ECOSYSTEM CHARACTERIZATION & IMPACTS

5.1 Introduction............................................ 185.2 Wetland Delineation..................................... 18

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5.3 Vegetative Stress: North & South Disposal Sites........ 195.4 Terrestrial & Sensitive Ecosystems...................... 19

5.4.1 Terrestrial Habitats............................. 195.4.2 Terrestrial Exposure to Lead..................... 195.4.3 Sensitive Habitats............................... 19

5.5 Fish Toxicity........................................... 215.6 Conclusions............................................. 22

CHAPTER 6: NATURE AND EXTENT OF CONTAMINATION

6.1 Introduction............................................ 246.2 Data Review............................................. 256.3 Impacts to the Christina River.......................... 266.4 Chemical Loading, Chemical Distribution and Data Gaps... 276.5 Sample Location Validity and Comparability.............. 276.6 Conclusions............................................. 27

CHAPTER 7t GENERAL CONCLUSIONS7.1 Contaminants of Concern.................................. 297.2 Reference Condition..................................... 307.3 Site Ecosystem Characterization and Impact.............. 307.4 Nature and Extent of Contamination...................... 30

CHAPTER 8s RECOMMENDATIONS8.1 Introduction............................................ 328.2 Reference Condition..................................... 328.3 Site Ecosystem Characterization and Impact.............. 338.4 Nature and Extent of Contamination...................... 35

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DRAFT DuPont Newport Site Review; Review of Ecological Concerns

Chapter 1INTRODUCTION

1.1 Report ObjectivesAt the request of the U.S. Environmental Protection Agency (EPA),Dynamac Corporation reviewed a number of pertinent documents andrelated agency comments for the DuPont-Newport Superfund Site(Site). The objective of this review was to evaluate Woodward-Clyde Consultants (WCC) study of the Site, and their subsequentconclusions as they relate to ecological impacts and potentialhuman health risks.

1.2 Scope of WorkDynamac reviewed the following technical reports developed fromthe previous studies:

1) Remedial Investigation Report (RI), (1991c);2) Environmental Evaluation Report (EE), (1991a);3) Wetlands Investigation (WI) Phase II, III and

Supplemental III, (1989, 1990, 1991e);4) Data Sufficiency Report (DSR), (1991e) and5) Risk Assessment (RA), (199la).

These documents were generated by Woodward-Clyde Consultants aspart of the Remedial Investigation/Feasibility Study (RI/FS)program in accordance with the July 22, 1988 AdministrativeConsent Order (AGO) executed by the U.S. Environmental ProtectionAgency (EPA) . Dynamac ascertained that Remedial Investigation(RI) activities began at the subject site during the summer of1987. A Summary of the documents listed above are included inChapter 2 of this report.

These documents were specifically evaluated for their content asthey relate to actual or potential impacts of chemicals to theecosystems at the Site and surrounding area. Thus, allaccessible and pertinent data associated with chemical releasesor measured chemical concentrations at the Site were appraised.Both qualitative and quantitative data were noted, compiled andcompared. Conclusions were made based on the nature, magnitude,and transience or permanence of observed or expected effects ofthe Site related chemicals on the ecosystems.

From the review of these documents, with ecological criteria offoremost examination,- five major areas of concern were identified

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The general areas of concern are as follows:

1) Contaminants of Concern, (Chapter 3)2) Reference Condition, (Chapter 4)3) Site Ecosystem Characterization, and (Chapter 5)4) Nature and Extent of Contamination. (Chapter 6)

In the areas where ecosystem impacts have been identified andinconsistent or erroneous conclusions have been drawn from thecollected data, or where apparent data gaps were observed,recommendations were made. General conclusions about the RI todate are made in Chapter 7. Recommendations are made in Chapter8 of this report.

1.2.1 Components of a Proper Ecological AssessmentThe primary goal of the RI/FS process is to gather sufficientinformation to support an informed risk management decision thatwill enable decision makers to select an appropriate remedialstrategy at a given site. A properly developed RI provides thebasic framework for site characterization activities, includinghuman health and ecological assessment.

Ecological assessment is a qualitative and/or quantitativeinvestigation of the actual or potential impacts of a site on theecosystem or parts of ecosystems within the site boundary andsurrounding areas. The terms 'ecological assessment' and'ecological evaluation', as used in this report, areinterchangeable.

Ecological Assessments evaluate pertinent ecological aspects of afacility in an applied scientific framework. These ecologicalaspects include, but are not limited to:

- Mapping Ecosystems within or near the site, [WCC coverage reviewed in Chapter 5 of this report]

- Establishment of a Reference Condition[WCC coverage reviewed in Chapter 4 of this report]

- Determination of a Healthy or Impacted Ecosystem[WCC coverage reviewed in Chapter 4 of this report]

- Effects of the site's contaminants on Impacted Ecosystem(s) ,[WCC coverage reviewed in Chapter 6 of this report]

To meet RI/FS goals, the delineation of wetlands, ecosystemmapping, and determination of Sensitive, Protected or Special

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Status Habitats and Threatened or Endangered Species isparticularly crucial due to the DuPont-Newport Site's locationbordering the Christina River. And, as with any RI/FS site, thechemical hazards must be identified and characterizedappropriately. This would include characterizing thecontaminants, the potential exposures, and the potentiallyexposed populations to determine what risks need to be reduced oreliminated and what exposures need to be prevented.

1.3 Site Location and DescriptionThe DuPont-Newport Superfund Site is located south of Newport,Delaware, and bisected by the Christina River. Figure 1 providesa map of the site location. Historically, the study area of theSite consisted of the following areas:

1) The Operations Area• The CIBA-GEIGY Newport Plant Area• DuPont Holly Run Plant

2) Two Inactive Landfills• North Disposal Site• South Disposal Site

3) The Associated Wetlands

4) The Associated Segment of the Christina River

5) The Potentially Impacted Groundwater

6) A Recreational Area Northwest of Operations Area(Ballpark)

1.4 Site HistoryThe Newport Plant is a pigment manufacturing plant now owned byCIBA-GEIGY. The plant was originally owned and operated (from1902 to 1929) by Heinrik J. Krebs for the manufacturing ofLithopone, an inorganic pigment containing barium and zinc. In1929, DuPont purchased the plant and continued to manufactureLithopone along with other materials, including organic andinorganic pigments. CIBA-GEIGY purchased the plant from DuPontin 1984. In 1948 the plant began manufacturing yellow copperphthalocyanine pigment (CPC). Quinacridone pigment (QA)production began in 1958. CPC was no longer produced after 1984,but QA is still being produced today by CIBA-GEIGY.

During plant operations, two portions of the Site bordering theChristina River were landfilled as a means of waste disposal.

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DRAFT DuPont Newport Site Review: Review of Ecological Concerns_________

Landfilling occurred in both the North and South Disposal Sites.The South Disposal Site operated from approximately 1902 to 1953;the North Disposal Site was capped in 1974. No information onlandfill liners was provided.

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Figure 1. Site Location Map

»• f-m - s »*•» X Qv\«

DUPONT NEWPORTcrrc A OCA

MAP SOURCE:USGS MAP7.5 MINURE SERES (TOPOGRAPHIC)W1MINGTON SOUTH. DELAWARENEW JERSEY QUADRANGLEPHOTOREV1SED 19»7

2000 4000 FT

rSCALE

SITE AREA - 1987DUPONT - NEWPORT ENVIRONMENTAL EVALUATION

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DRAFT DuPont Nevqport Site Review; Review of Ecological Concerns

Chapter 2SUMMARY OF PREVIOUS SITE INVESTIGATIONS

2.1 Past Site Investigation ReportsA number of reports were reviewed to ascertain the nature andextent of contamination, the potential impacts to human healthand the environment, and to compile the various data generated inthe various phases of investigation to determine the completenessand validity of the conclusions therein. A brief description ofthe reports that were reviewed for this report and previouslyutilized in the development of the Draft RI (dated November 1,1991) follows below:

(1) Proposed RI/FS Work Plan (Phase I): dated July 20, 1987,served as the initial phase (Phase I) of the remedialinvestigation. It was designed to collect data to determinethe need for a complete RI/FS program.

(2) Work Plan (Phase II), RI/FS, DuPont Newport Site, Volumes I,II, and III: dated July 28, 1988, presented the results ofthe RI Phase I and outlined an RI Phase II, an EndangermentAssessment, and a Feasibility Study. The Work Plan wasprepared to address the objectives of the RI/FS specified inthe Consent Order.

(3) Wetlands Investigation (Phase II), DuPont Newport Site:dated March 23, 1989, contained a summary of the resultsfrom an investigation of the sediment and surface waterchemistry, in the wetland areas associated with the DuPont-Newport Site. This investigation was conducted as part ofthe RI Phase II.

(4) Data Sufficiency Memorandum and Remedial Investigation-PhaseII: dated April 27, 1989, was designed to document theresults of the RI Phase II and evaluate the sufficiency ofthe RI data in accordance with Section 3.2 of the Work Plan.The data from both Phase I and Phase II were evaluated todetermine their completeness to support the EndangermentAssessment and the Feasibility Study.

(5) Data Sufficiency Supplement, Remedial Investigation, PhaseII DuPont Newport Site: dated November 1989, was developedby WCC in response to EPA review comments to the DataSufficiency Memorandum dated April 27, 1989 and the June 29,1989 meeting between the EPA and DuPont. The additional

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DRAFT DuPont Newport Site Review; Review of Ecological Concerns__________

study included a review of all available historical maps,files, and photographs to prepare a summary of historicalprocesses and materials handling at the Newport Plant.

(6) Phase III Wetlands Investigation, Technical Data SummaryReport, DuPont Newport Site: dated January 1990, containedthe findings of additional data collection completed toassess the potential biological impacts associated with theDuPont-Newport Site, and to further explain the datacollected in the Phase II wetlands study.

(7) Final Phase III Remedial Investigation Work Plan: datedFebruary 5, 1991, was prepared in response to earlierrequests by EPA from correspondence dated January 17 andMarch 8, 1990. The RI Phase III Work Plan discussedadditional investigations at the Ciba-Geigy Newport Plantarea, DuPont Holly Run Plant area, and the South Disposalsite, involving all of the potentially impacted groundwater,associated wetlands, and the associated portion of theChristina River.

(8) Phase III Remedial Investigation, Data Sufficiency Report,DuPont-Newport Site, Volumes 1 through 4: dated May 17,1991, represented the data collected during the Phase IIIRemedial Investigation conducted between April 1990 andApril 1991.

(9) Draft Risk Assessment Report (consisted of a two volumeassessment including a Human Health Evaluation): datedOctober 14, 1991 and an Environmental Evaluation dated July30, 1991. These evaluations were prepared to quantify thepotential risks to public health and the environment.

From review of the above reports, definitive conclusions aboutthe environmental findings, to date, were difficult. This wasdue primarily to the voluminous amounts of data that have beengenerated from the various portions of the RI program at theSite. Constant cross-referencing between the reports and datatables was unavoidable, and still with the amount of time spentfor this review, there are doubts present about what activitieshave been completed, and whether or not these activities arerepresentative of the Site ecosystems.

jThese points are critical since the Risk Assessment 'andEnvironmental Evaluation Report rely inherently upon the findingsand organization of the various ecological assessment data. Whenthese critical data are disorganized, disjointed andunmanageable, then the conclusions drawn from these data mayfollow suit, that is, the final conclusions may be erroneous.

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Chapter 3CONTAMINANTS OF CONCERN

3.1 IntroductionThis section begins with a definition of contaminants of concern(COCs). Following that is a critique of the rationale used forselection of COCs in the DuPont-Newport Environmental Evaluation(EE) .

3.2 General Discussion of Contaminants of Concern:Importance and DefinitionThe contaminants of concern selection procedure should bedesigned to identify the highest risk chemicals at a site so thatthe ecological assessment remains focused on an evaluation of thechemicals of greatest concern. The following chemicalcharacteristics are important factors in ranking chemicals in theCOCs selection process:

- quantity of chemical stored, disposed of on-site or released,- chemical toxicity,- measured chemical concentrations at the site,- mobility of chemicals through various exposure pathways,- bioavailability of the chemicals to the ecosystem, and- potential of the chemical to bioaccumulate.

3.3 COC Selection RationaleThe choice of COCs for the Environmental Evaluation (EE) weremade on the basis of a comparison between: 1) river and wetlandssediment concentrations and sediment quality criteria and 2)sediment chemical concentrations and field referenceconcentrations. Dynamac has several general reservations aboutthe selection procedure for COCs in the EE, which are outlinedbelow. A discussion of the failure to include cadmium, chromium,and organic compounds as COCs as a result of the selectionrationale follows.

It is not clear why WCC only considered sediment contaminationwhen choosing the COCs for the EE. Environmental exposure mediaat the site include surface soils, surface water, and biota;therefore the COCs should have been chosen with respect tocontaminant prevalence in these media as well.

In Section 5.1 of the EE, the following selection process bywhich metals were chosen as COCs was described:

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"If the lower of either the Threshold Value Guideline (USEPA,1985) or the Limit of Tolerance Level (OME, 1989) was exceeded byone order of magnitude in at least one sample and the metal waspresent in concentrations exceeding field referenceconcentrations, it was placed on the list of the sevenconstituents of concern for the Newport Site EE shown below. "

The requirement for metals concentrations to exceed EPA and OME(Ontario Ministry of the Environment) standards by an order ofmagnitude has not been justified. In response to EPA's requestfor a justification of the imposition of this criterion(Sturgeon, 9/14/91) WCC replied in part,

"Since there are no regulatory criteria and since severalguidelines were considered, the "order of magnitude criterion"was proposed in this investigation as a reasonable screeningtool".

Neither of these considerations is relevant to the plausibilityof the use of the order of magnitude criterion as a screeningtool. There is no mathematical operation in the derivation ofthe EPA Threshold Values or the OME Limit of Tolerance Levels,(from water quality standards, K 's, and overt sediment toxicitytests) that would provide a justification for imposition of arequirement for an order of magnitude excess (USEPA, 1985; OME,1989) . The apparently arbitrary order of magnitude criterion mayexclude metals from consideration that should be included in theEE. Specifically, Dynamac is concerned that cadmium and chromiumshould be included as COCs for all areas at the Newport site.

3.3.1 CadmiumCadmium was not included as a COG for the wetlands of the Northor South Disposal sites, although it was detected inconcentrations in excess of EPA threshold values in sediments ofthe North Disposal Site Pond, the South Disposal Site Pond, andthe South Disposal Site Drainageway (Phase III wetlandsinvestigation).

In Section 4.1 of the EE, cadmium is called a "site targetparameter" in the following excerpt:

"The constituents associated with wastes disposed at the NorthDisposal Site include the site target parameters barium, zinc andcadmium from Lithopone wastes, .. .Waste materials from theLithopone pigment process were also disposed at the SouthDisposal site.".

Furthermore, in Section 5-.2, the EE states:

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"Cadmium also occurred in high levels in samples from the Northand South Disposal Site Wetlands, but the levels did not exceedthe plus one order of magnitude greater than threshold valueguideline established above.".

Since according to the EE and previous WCC reports cadmium ispresent in site sediments at levels in excess of the EPAThreshold values and is considered by WCC (page 4-1) to be aconstituent of the Lithopone wastes buried in the North and Southdisposal site wetlands, the only criterion preventing cadmiumfrom being selected as a chemical of concern for the wetlands isthe arbitrary order of magnitude criterion.

3.3.2 ChromiumChromium was not included in the list of COCs for the South SiteDisposal wetlands although it was detected in sediments from theSouth Disposal Site Drainageway (at a maximum concentration of72.4 ppm) and in the South Disposal site pond'(maximumconcentration of 77 ppm) (Phase III Wetlands investigation).These levels are in excess of the EPA threshold value and OMELimit of Tolerance level, both equal to 25 ppm, but are muchlower than the concentration at RS15, the reference station.

It is inappropriate to use comparison to the contaminated RS15reference station as a criterion for selection of COC in thewetlands. Chromium concentrations are highly elevated in thesediments at station RS15 (RS15 concentrations are 141 ppm; 145ppm concentrations of chromium are strongly associated withadverse biological effects) (NOAA, 1990). Chromium from upstreamsources in the Christina River that are contaminating RS15 areundoubtedly not contributing to chromium levels in the SouthDisposal site wetlands.

The Biological Technical Assistance Group (STAG), (Sturgeon, 19919/14 letter, Comment 3) requested that WCC search the literaturefor reference values of contaminants for the site from a knownClean area. WCC responded in part:

"Clean is a relative term which makes response to this commentdifficult. As far as has been determined there is no area in thevicinity of the Site which represents a 'clean' freshwater tidalarea.".

Dynamac believes it is not necessary to make a comparison to afield station reference location in order to evaluate relativeenvironmental quality. In fact, WCC has not done so for surfacewater quality evaluations in the EE. Rather than present data onaverage background levels of chromium, WCC has provided in the EEbackground chromium concentrations "from industrial zone waters";


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no literature values of the average chromium concentrations inclean sediments are presented in the EE.

The exclusions of cadmium as a COC in the North and Southdisposal site wetlands and of chromium as a COC in the SouthDisposal site wetlands are not justified because theconcentrations present are clearly elevated and are clearly siterelated.

3.3.3 TCE, PCE, and PAHEvidence of TCE, PCE, and PAH contamination has been mentioned inprevious WCC documents. Sample data and a discussion of theextent of contamination by these organic compounds is missingfrom the EE; depending on the levels present, these could beadditional COCs for the EE.

3.4 Conclusions

o COC selection for the EE has been inappropriately basedon consideration of contaminant levels in sedimentswithout consideration of prevalence of contaminants insoil, surface water or biota;

o The "order of magnitude" selection criterion of the COCselection rationale has no apparent mathematical orscientific basis. Use of this criterion has led tofailure to include cadmium and chromium as COCs for allareas of the site.

o Neither the extent of PCE, TCE and PAH contamination atthe site nor their fitness as COCs is discussed in theEE.


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Chapter 4REFERENCE CONDITIONS

4.1 IntroductionWCC has used stations RS15 (a contaminated upstream riverstation) and AS12 (a wetlands station for which contaminationlevels were not given in the EE) as reference conditions for thesediment quality triad analysis and to reach other conclusionsabout the site. In this section, the validity of the reasoningbehind the choice of reference conditions, the errors in designof the sediment triad analysis, and the soundness of theconclusions drawn from the results of the sediment quality triadanalysis are discussed in detail.

4.2 Use of Contaminated Site RS15 as Reference ConditionDuPont has chosen a contaminated site. Station RS15, as itsreference station for the EE. A contaminated reference conditionis conceptually different from a pristine reference condition.Comparisons between impact sites and contaminated referenceconditions can only be used to draw a limited number ofconclusions. For example, a comparison between a contaminatedupstream reference station and downstream stations can be used todocument the incremental contribution of site contamination tothe degradation of near-site downstream stations; this may be ofinterest for setting remedial clean-up goals for the near-siteriver stations.

However, it is an inappropriate and invalid use of a contaminatedreference station to compare it to areas that are not subject tothe same sources of contamination. This is what theinvestigators have done in the EE. The upstream riverine stationRS15 has been used as a reference station not only for thesediments in the near-site Christina River, but also for those inthe North and South Disposal sites and their associated wetlandsand drainageways. Based on site historical data presented byDuPont in previous reports, all of the contamination at theselocations has been directly caused by the disposal of pigment-manufacturing process wastes and facility debris deposited thereby E.I. de Pont and de Nemours and Company, Inc. and theirpredecessors since 1902. There is no hydrological connectionbetween these areas and the background sources of contaminationin the Christina River. It is therefore inappropriate to attemptto account for any portion of the contamination in the sediments,surface water, or soils of the non-riverine areas of the site by


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comparisons to RS15.

On the fifth page of their response to EPA comments on the EE,(9/14/91; page 5), the investigators have made three inaccuratestatements regarding the use of RS15 as a reference station.These statements are reproduced below in italic type, followed byDynamac's observations on them.

1) "Based on the data collected to date, Station RS15 is 'clean'to the extent that it is out of the influence of the DuPont-Newport site and apparently reflects 'background' conditions asthey exist today. For this reason it is suitable as a basis forcomparison with other sites in the study area."

This statement is inaccurate because in fact RS15 only reflects"background" conditions in the Christina River and is thereforeonly suitable as a basis for comparison with near-site stationsin the Christina River.2) "Likewise, comparing site data to what would be expected tooccur in clean areas in the literature does not satisfy theobjectives of this EE".

If a comparison between conditions at the North and SouthDisposal sites, their associated wetlands and drainageways, andthe ballpark to literature reference values or pristine referencestations does not satisfy the objectives of the Newport-DuPontEE, then the objectives must be changed. By definition, theobjective of the EE is to characterize the extent of the adverseecological impacts caused by decades of discharge of chemical andsolid wastes into the environment on both sides of the ChristinaRiver at Newport, Delaware.

In response to the following EPA request (also on page 5,9/14/91):"compare the site to what would be expected in this vicinity ifno contamination existed",

Woodward-Clyde responded in part,

3) "Data on benthic communities which would be expected to occurin this system in pre-industrial times, while interesting, arenot considered germane to the context of this investigation".

This response is inaccurate because a comparison between the non-riverine contaminated areas at the Newport site and conditionsthat obtained there before manufacturing operations began at theturn of the century is not only "germane to the context" of theEE but it is in fact definitional of it. The contamination

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currently present in the disposal areas and associated wetlandsand drainageways is due solely to the historical operation of thefacilities at the DuPont -Newport site. An evaluation of theimpact of the facility on the surrounding ecosystem must consideras its baseline, the condition of the site before operationsbegan there.Furthermore, WCC's response to EPA's request attributesdisproportionate importance to benthic community data. Thetendency to place undue emphasis on the significance of benthiccommunity data is pervasive in the EE. An evaluation of site-impacted benthic community data, while critical, is notequivalent to and should not be confused with an ecologicalassessment.

4.3 Use of RS15 as a Reference Condition for Biotic RelativeAbundanceThe ratio of abundance of dipteran insect larvae to the abundanceof oligochaete worms at the highly contaminated river stationsRS07, RS11, RS12, and RS14 (EE, page 7-3) was shown in the EE tobe markedly reduced relative to the same ratio at referencestation RS15. Vis a vis these results, WCC makes the followingrather guarded interpretation:

the ratio of dipterans to oligochaetes is taken as an indexof pollutional stress (Howmiller and Scott, 1977: King and Ball,1964), data from these stations may suggest impacts.".

Since presumably WCC does consider this ratio an index ofpollutional stress, (or the ratio would not have been calculated)it appears that a much stronger conclusion can be drawn fromthese results, namely that the benthos of near- site riverinesediments are suffering from pollutional stress relative to thebenthos at RS15.

4.4 Combined Use of RS15 and AS12 as Reference Conditions in theSediment Triad Analysis

Station AS12 (located upstream in the North Disposal SiteWetlands) is used as the reference station for biotic abundancein the site wetlands. It is not clear from the data presented inthe EE whether or not AS12 is contaminated. WCC's use of thecomparison to AS12 in conjunction with a comparison to RS15 inthe sediment quality triad analysis may lead to misinterpretationof the resulting triaxial plots.

At least two of the three parameters in the sediment qualitytriad analysis were normalized by comparison to differingreference stations. The reference station for sediment


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contamination was RS15, the reference station for benthicabundance was AS12, and the reference station for sedimenttoxicity bioassay results was unspecified. (Dynamac disagreeswith the choice of RS15 as a reference station for site wetlandsstations for any of the three parameters; see Section 5.1 above).

Station AS12 is apparently less contaminated than RS15, sonormalization to levels at RS15 in the contamination arm of eachtriaxial plot results in plots for each wetlands station that areless skewed than if AS12 were the reference station for all threetriad parameters (Figures 6 and 7, EE). This alters the relativepositions of the triaxial plots for the wetlands sediments,making an accurate interpretation of their relative quality toAS12 impossible.

4.5 Design Flaw in Sediment Triad Analysis: Normalization ofSediment Contamination Data to Calcium Concentrations

Characterization of the physical/chemical characteristics ofsediments, such as sediment texture and total organic carbon, isan integral part of the sediment quality triad classificationscheme proposed by Long (1989). Differences in thephysical/chemical characteristics .of sediments can affect theoutcome of the triad analysis by affecting the bioavailability ofthe contaminants. For example, measured contaminantconcentrations are often normalized to total organic carboncontent to account for the tendency for generally higherretention and lower bioavailability of contaminants by highlyorganically enriched sediments (Long, 1989).

In the EE, sediment metal concentrations are normalized tocalcium concentrations rather than to either grain-size ororganic carbon content for the following reasons:

1) calcium is the "most conservative indigenous element found inthe sediment"

2) calcium is "the indigenous element with the least variationamong stations"

3) normalization to a single geochemical variable would betterserve the requirements of the sediment quality triad analysisthan would normalization to grain-size or organic matter.

Dynamac disagrees that normalization to calcium better serves therequirements of the sediment quality triad analysis. There is norelationship between either: 1) sediment physical/chemicalcharacteristics and calcium concentration, or 2) tendency forCOCs to become bioavailable and calcium concentration.

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Therefore, incorporation of calcium concentrations into the COCconcentrations is not informative. On the contrary,incorporation of relative calcium levels into the sediment triadby presenting the sediment contaminant parameter on the triaxialplot as an RTR based on calcium content undoubtedly obscures realtrends in contaminant behavior between stations.

In order to provide a contribution to the ease of interpretationof the sediment quality triad analysis, concentrations would haveto be normalized to a variable that is in some way related to thetendency of metals to be adsorbed, chelated, or otherwisesequestered in sediments. It should be noted that there is norule in the sediment triad approach that sediment contaminantlevels have to be normalized to anything (Long, 1989). WCCstates that they normalized COC data

"to improve resolution of the station to station differences inthe constituents of concern".

Improved resolution is a worthwhile goal, however, normalizationto calcium will not produce such a resolution. The lack ofresolution between stations could more reasonably be attributedto the failure to select a pristine reference station and to thecontamination present in all samples.

4.6 Sediment Quality Triad .Analysis InterpretationIn the original paper describing the sediment quality triadapproach to classification of sediments, Long (1989) makes thefollowing statements about conclusions that can validly be drawnfrom the triad data:

"The bioassay data provide direct evidence of whether or not thesediments are toxic to selected test organisms. If they aretoxic, it can be assumed that the chemical contaminants werebioavailable to the test organisms".

"Evidence of severely altered benthos coupled with evidence ofsediment toxicity provide a powerful argument that contaminatedsediments are biologically damaging".

Long does not state, and it is fallacious to assume, that thereverse of the statements is also true. That is, WCC has madethe assumption (EE, page 7-3) that because South disposal sitebenthic fauna was abundant despite high levels of almost allCOCs, it must follow that metals in the South' Disposal Sitewetlands are not bioavailable. This reasoning is fallaciousbecause the sediment bioassay could yield an apparent result ofno toxicity for reasons other than limited contaminantbioavailability (such as errors in the sampling for or


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DRAFT DuPont Newport Site Review: Review of Ecological Concerns__________

performance of the bioassay). In other words, while thedemonstration of sediment toxicity is necessary and sufficient toshow that contaminants are bioavailable, lack of demonstratedtoxicity is necessary but insufficient to show that thecontaminants are not bioavailable.

Only two stations were sampled for the sediment triad analysis ofthe South Disposal Site Wetlands. This number of samples isinsufficient to characterize the relative sediment quality ofthese wetlands.

4.7 Conclusionso WCC has used comparisons between RS15 (a contaminatedupstream reference station) and site wetlands to reachconclusions about sediment and benthic community quality inthe wetlands. These comparisons have been incorporated inthe sediment quality triad analyses for the wetlands (Figures6 and 7, EE). Use of RS15 to assess the quality of thewetlands is inappropriate because the wetlands anddrainageways are not subject to the upstream sources ofcontamination which are affecting RS15. Based on the sitehistory presented in the EE and related documents, allcontamination of the site wetlands is the direct result ofwaste disposal practices at the DuPont facility between 1900and 1974. Before operations began at the site in 1900, thearea was pristine. Therefore the wetlands and drainagewaysneed to be compared to a pristine reference condition; eitheran uncontaminated wetlands or literature values.

o An insufficient number of samples (two) were collected to ,characterize the quality of wetlands sediments using thesediment triad approach.

o Normalization of sediment contaminant levels to calcium is notinformative for the sediment triad analysis. The normalizationprocedure is designed to yield information about the relativebioavailability of contaminants in sediments. Since calciumconcentrations are unrelated to either the physical/chemicalnature of the sediments or to the relative bioavailability ofmetals in sediments, normalization to calcium will tend toobfuscate rather than elucidate sediment quality trends.

o Fallacious reasoning has led to the conclusion that metals inSouth Disposal Site soils are not bioavailable.


1R3I2I3I4


Chapter 5SITE ECOSYSTEM CHARACTERIZATION AND IMPACTS

5.1 IntroductionBiological communities (ecosystems) are visible indicators ofenvironmental health. Ecological integrity implies environmentalhealth, and as can be seen from many public health riskassessments, human health is directly related to ecologicalhealth. Therefore, a comprehensive environmental complianceprogram will include ecological impacts data, in addition to thetraditional chemical data collected to evaluate and correctchemical impacts to the environment.

5.2 Wetland DelineationWCC has provided maps depicting "Wetland Boundaries", however,these maps are qualified with "Note: Field Verification limitedonly to boundaries on the DuPont-Newport Site in the vicinity ofdisposal sites". There were no maps found in the EE or other RIreports that indicate where the "boundaries" of the Dupont-Newport Site are located, therefore, it was not known to whatextent this wetland field verification was conducted.

This wetland determination was "field verified" based on U.S.Fish and Wildlife Service - National Wetland Inventory Maps,which should be utilized only as a basis for preliminaryinformation. A field verification would include hydric soildeterminations and hydric soil mapping, plant transectidentification, indicator group (ie, OBL, FACW, FAC, and UPL) andnumber/types of plant occurrences along the transect,hydrological evaluations and other justification for wetlandboundary lines. There were no formal wetland delineation mapsgenerated to indicate actual wetland boundaries.

Infra-Red (IR) aerial photographs and topographical maps werereviewed to locate wetlands and water drainageways at and nearthe Site. This review revealed areas of wetlands and drainagepathways which historically and currently provide surfacedrainage from the Site. These areas are located southwest of theNorth Disposal Site and were not considered or delineated in thereports. There is an unnamed drainageway that meanders throughsome portions of the wet areas southwest of the North DisposalSite and appears to eventually drain into the Christina River.Sample locations AS-10 and AS-11 are located at least five-hundred (500) feet northeast of this area. Even if this area isnot considered Dupont-Newport property, it should becharacterized for off-site migration, since it appears to be anintegral part of the wetlands and drainageways associated with


SR3I2135


this investigation.

5.3 Vegetative Stress: North and South Disposal SitesFrom review of historical aerial photographs (most recentphotograph: 1988), there are a couple of areas that appear to bedisturbed, that is, there are obvious disruptions in thevegetation and bare soils can be seen. An area west of the NorthDisposal Area, located near AS-07, has visible areas of reducedvegetation. This area had some of the highest metalsconcentrations measured at the site, and extremely poor survivalin toxicity data. This suggests there may be a correlationbetween high metal concentrations and vegetative stress. Figure13 is a summary of the measured metal concentrations in the NorthDisposal Site Drainageway. Although this figure confirms thatAS-07 is clearly an area of high metals concentration, it alsoshows that there is a high probability that metals are beingassimilated into the wetlands.

There are data that indicate that some surface water meanderstowards AS-10 and AS-11, after passing AS-07. There were alsomeasurable metal concentrations at these points, which opens thepossibility that the area around RS-13 and RS-14 is not the onlydrainage pathway for the North Disposal Site.

An area located near the South Disposal Site exhibits somevegetative stress and exposed soils (Aerial Photograph of Sitedated June 1988). This disturbed area is just upgradient of AS-03 and AW-03, which are also areas of measurably high metalsconcentrations.

The toxicity test data, the metal concentrations in sediment, andthe water quality data for both of these disturbed areas (AS-07and AS-03) indicate that there may be a correlation between theseexposed areas exhibiting stressed vegetation and toxic metalconcentrations. This information presents further arguments formore comprehensive characterization of the wetlands downgradientfrom the North and South Disposal Site Drainageways.

5.4 Terrestrial and Sensitive EcosystemsA baseline survey map of the existing ecology, includingterrestrial ecosystems and ecotones between uplands and wetlands,at the site was not provided. Evaluation of the site withrespect to species diversity/abundance, as compared to areference or background condition, was not provided. .

5.4.1 Terrestrial Habitats5.4.1.1 Necessary Steps for Ecological Risk CharacterizationThe North and South Disposal Sites are terrestrial habitats atthe DuPont-Newport site. No terrestrial receptor risk assesment


SR312I36


has been conducted. A risk assessment includes the followingsteps:

1) receptor identification,2) exposure scenario development,3) quantitative or qualitative estimation of dose received,4) dose-response relationship characterization, and5) risk characterization.

WCC has undertaken none of the component steps of a terrestrialecological risk assessment. Nevertheless, several riskcharacterizations concerning terrestrial receptors appear in theEE, such as the following,

"Based on literature reviewed for cadmium (Eisler, 1985), copper(Moore and Ramamoorthy, 1984) and lead (Eisler, 1988), exposureby wildlife to levels of these constituents measured on the NorthDisposal site are not expected to result in toxicity."

In order to accurately characterize risk, the investigators mustsomehow consider the estimated dose of each toxicant that wouldbe received by target organisms by constructing hypotheticalexposure scenarios. Although "wildlife and birds" and "mammalsand birds which may utilize the area" (EE page 6-3, page 6-5) arementioned as receptors at the North and South Disposal sites, WCChas not constructed exposure scenarios for these receptors, andso has not estimated the dose of each toxicant that would bereceived by these receptors via direct contact with surface soilsor ingestion of contaminated forage following plant uptake ofcontaminants in surface soil.

There are some statements in the EE that may indicate areluctance to confront the potentially serious ecotoxicologicaleffects that could occur in the terrestrial habitats at theDuPont-Newport site given the surface soils concentrations oftoxicants reported. Cadmium concentrations as high as 65.7 mg/kghave been detected in surface soils. WCC reports in the EE that"in contaminated areas cadmium can result in toxic effects inmammals through ingestion of contaminated vegetation.Contaminated grass (9 mg/kg) was blamed for the death of ahorse". In the same paragraph, WCC states (without a reference),"investigations with terrestrial animals have siiown that undernatural conditions absorption (of cadmium) from thegastrointestinal tract is poor and hence, poisoning is unlikely".

5.4.2 LeadLead is an accumulative metabolic poison that causes a variety oftoxic and sublethal effects in mammals, birds, fish, andinvertebrates (Eisler, 1988) and is one of the COCs for the EE.


. flR3!2i37

DRAFT DuPont Newport Site Review; Review o£ Ecological Concerns__________

It has been detected in elevated concentrations in all siteexposure media (up to 2.7% in sediments of the North DisposalSite Drainageway) (EE, 1991). Lead concentrations of 1520 ppmhave been detected in South Disposal site surface soils. In thesummary of impacts section, WCC fails to mention the 1520 ppmlead levels, saying instead,"levels of" all constituents of concern except barium measured insoils within several feet of the surface of the South Disposalsite, are below levels which have been shown to produce toxiceffects in wildlife".No reference or rationale is provided for this statement. Incontrast to WCC's assertion, it is likely that wildlife exposedto 1520 ppm lead in soil will experience non-lethal toxiceffects. WCC has not presented any discussion of the sub-lethaleffects of lead in environmental receptors.

5.4.3 Sensitive HabitatsA comprehensive determination of Sensitive, Protected or Specialstatus habitats, and Threatened or Endangered species was notprovided. The Remedial Investigation report, Nov.1,1991, section3.2.4 Sensitive Habitats of the EE, uses a personal communicationwith a U.S. Fish & Wildlife employee as the completeinvestigation and determination. In the wetland areas, GreatBlue Heron, Black-Crowned Night Heron, Osprey and a Bald Eagle,listed on the Endangered Species List for Delaware, were observednear the site. The criteria used to determine if Sensitive,Protected or Special status habitats were present were notdefined. A valid conclusion cannot be drawn without aterrestrial habitat evaluation and ecosystem map of the projectimpact area. Information gathered from evaluations performed byDNREC Natural Heritage Program was not provided.

;5.5 Fish Sampling5.5.1 Inadequacy of Fish Contamination DatabaseThe extent of fish tissue contamination data is insufficient topermit an evaluation of the influence of site contamination onthe fisheries in the Christina River. Fish were collected fromonly two locations. Elevated concentrations of all of the metalsof concern in the EE have been detected in whole-fish samples ofpumpkinseed and silvery minnow collected near the site relativeto those collected at RS04, several miles upstream. Pumpkinseedfish and silvery minnow are unlikely to migrate significantdistances up or down the river. Thus the elevated levels of allthe site metals of concern in the whole-body samples of thesefish may be significant as an indication that the DuPont-Newportis contributing to fish contamination. In order to demonstratewhether or not the site is causing contamination of fish, WCCwould have to collect samples from a number of locations alongthe river.

Dynamac C o r p o r a t i o n ~21

AR3I2I38


5.5.2 Failure bo Consider Fish or Fish Predators as TargetOrganismsWCC has failed to evaluate the impact of the high metalconcentrations in whole fish samples. The only interpretation ofthe fish sampling data to appear in the EE is reproduced below:

"while all metals of" concern have been identified in whole fishtissues throughout the Christina River study area, they are notpresent in concentrations that would be considered toxic.Furthermore, it is important to note that lead was not foundabove the detection limit in any of the fish fillet samples".

It is not clear from this statement if WCC means the levels"would not be considered toxic" to humans, to the fish, or tonon-human predators. In the absence of any information on dose-response relationships exhibited by the COCs in fish and in theirpredators, no conclusions can be drawn about the metalconcentrations observed. All WCC has done in the EE is todemonstrate that exposure to the site COCs is occurring. Therehas been no adequate toxicity assessment or risk characterizationconducted for fish and avian target organisms.

5.5.3 Failure to Characterize Surface Water Quality of theChristina RiverChristina River surface water contamination data, which could beused to conduct an approximate evaluation of the quality of thenear-site Christina River as a fish habitat, were not provided inthe EE. Reference is made in Section 6 to two isolated watersampling events, in August of 1987 and October of 1990. Thesewater samples were apparently filtered prior to analysis, whichmakes them inappropriate for use in an ecological assessment.Furthermore, restriction of the water sampling to only onelocation (just downstream of the site) prevents an evaluation ofthe impact of the site on the water quality of the ChristinaRiver.

5.6 Conclusions

o No wetland delineation reports were provided.

o A baseline survey map of the existing ecology, includingterrestrial ecosystems and ecotones between uplands andwetlands, at the site was not provided. Evaluation of the sitewith respect to species diversity/abundance, as compared to areference or background condition, was not provided.

o The impacts to Wetlands/Water movement in Wetlands has not beendetermined.


AR3I2I39

DRAFT DuPont Newport Site Review: Review of Ecological Concerns__________

o No evaluation of exposure or risk for terrestrial receptors hasbeen conducted.

o Lead ecotoxicity is not considered.

o Wording in the EE tends to discount the potentially seriousecotoxicological effects associated with soil contamination inthe North and South Disposal site soils.

o Fish sampling data from the Christina River are inadequate topermit an evaluation of site impact on the river's fisheries.

o Neither fish nor their non-human predators are considered astarget organisms.

o Water quality of the Christina River has not been characterizedwith respect to potential site impairment. Water samples werefiltered prior to analysis, rendering them useless forevaluation of ecological effects.


AR3I2UO


Chapter 6NATURE AND EXTENT OF CONTAMINATION

6.1 IntroductionThe primary goal of the RI/FS process is to gather sufficientinformation to support an informed risk management decision thatwill enable decision makers to select an appropriate remedialstrategy at a given site. A properly developed RI provides thebasic framework for site characterization activities, includinghuman health and environmental evaluations. In order to meetthese goals, the chemical hazards must be identified andcharacterized at the site appropriately. This would includecharacterizing the contaminants, the potential exposures, and thepotentially exposed populations to determine what risks need tobe reduced or eliminated and what exposures need to be prevented.

As part of the chemical hazard characterization, the nature, rateand extent of contamination release at the site must beestablished. This would include chemical types, chemicalabundance, rates of chemical release, chemical locations, andtoxicological data for these chemicals.

In this case, the Environmental Evaluation report (EE) wasexamined in conjunction with known information about the diverseecosystems that are located at and near the Site. An exhaustivereview of the data tables from the various RI phases and EE wasconducted to compare surface water, sediment and biotic findings.However, this review evidenced no conclusive or comprehensivetables summarizing the chemical data findings from the various RIphases. Furthermore, there were no graphic representations ormaps of the locations and concentrations of these chemical data.

6.2 Data ReviewIn an effort to facilitate data review and interpretation, thedata from the various RI phases were compiled for each samplinglocation. The data sampling locations were divided into threebasic areas:

1) Sample Locations along the Christina (Table la),2) Sample Locations in the North Disposal Site (Table Ib), and3) Sample Locations in the South Disposal Site (Table lc).

As can be seen in the Christina River Sediment Samples, Table la,



there were no surface water samples associated with any of thesediment samples. There were also only a few sample sites wheresediment data could be compared between any two RI samplingphases. And in no case were there any data available for allthree sampling phases at a single sample location point.

With so few samples there was little statistical confidence inthe actual values that were presented. The conclusions from theRI and EE were often based on contaminant concentrations thatcame from a single sampling event for any given samplinglocation. Any statistically valid analysis would include aseries of measurements, taken over time, to better approximatethe actual release to surface waters and sediments, as opposed toa one-time grab sample. Further, these minimal sampling eventsdo not reflect any temporal variations, including bioticinfluences, hydrologic fluctuations, or seasonal uptakes andreleases of chemicals (especially metals in wetlands). Therefore,in the absence of statistically valid data, and in an effort toapproach or maintain the "most conservative" estimates forprotecting human health and the environment, it would fit thateven concentrations that approach these guidelines (ie; ThresholdValues) would be considered for future monitoring, sampling orremediation considerations.

6.3 Impacts to the Christina RiverEndless arguments can be presented for various guidelines,criteria or reference conditions to establish a reasonable andacceptable chemical concentration. However, the selection orelimination of the various chemicals has prompted the variousagencies reviewing these reports to provide innumerable argumentscommunicating that there is "reasonable doubt" about the chosenscreening processes that were used throughout theseinvestigations. The underlying factor still remains that theSite is impacting both the wetland ecosystems at and near thesubject property and also the Christina River.

Figure 5, Summary of Christina River: Surficial SedimentChemical Analysis, graphically illustrates the sediment samplinglocations directly adjacent to the Site have increasedconcentrations of metals. Arguments about the Christina Riverwatershed being impacted from non-Site related sources seem to beirrelevant when these data clearly indicate that the increasedmetal concentrations in sediments are directly associated withthe Site. It is not difficult to conclude that these sedimentconcentrations are attributable to effluent discharges or surfacewater runoff into the Christina River from the Site. Thisunknown association between chemical concentrations from thesite, the sediment and surface water loading is only compoundedby the lack of water quality data associated with these sediment


AR3I2U2


sample locations.

In addition to arguments about degraded conditions of theChristina River from other non-site sources, further argument ispresented about the lack of consistent pattern of contaminationin the Christina River. This might be attributed to a lack ofdata collection logic, data interpretation and organization ordata presentation. For it seems obvious from the sediment samplesummary (Figure 5 of this report), that there is a direct linkbetween sediment metal concentrations and the Site (Figures 6-21of this report provide further data on contaminant concentrationsin Christina River surficial sediments).

6.4 Chemical Loading, Chemical Distribution and Data GapsChemical concentration is only one factor that can determine therelevance of a chemical. Another factor that should beconsidered is chemical loading. It does not appear that loadingwas evaluated with respect to the release of receiving waters.Basing the evaluation solely on concentration may obscure theactual events. In addition, it is essential to quantify theindividual sources of contaminants and the relationships betweenmedia, as well as the loading found in the receiving water body,to effectively define the nature and extent of the contaminantrelease. These reports did not clearly define the distributionbetween sediment, biota and water columns. Tables la, Ib and Icof this report, present the vast data gaps in the sampling logicof the RI Phases. Furthermore, no readily apparent format ofthis relationship was presented in the RI or EE reports.

Dynamac disagrees with WCC's statement in the Executive Summaryof the RI (p. ES-4) that " the horizontal and vertical limits ofthe target parameters in the soils and groundwater at the Sitehave been sufficiently delineated". According to WCC's statementin the DSR, RI, Phase III, p. ES-3, "subsurface sediments fromseveral North Disposal Site stations showed a trend of increasingmetals concentration with depth". The recent soil samplingconducted during the Phase III, RI did not adequateley sample thesediment from 12- 18 " depth (refer to Table 2 of this report).Only three locations were sampled at this depth; two were riverlocations, one of which was the reference (RS15) and the thirdwas in the pond on the South Disposal Site. WCC states in theDSR Section 4.3.2 (p.4-11) "problems occurred in the field,"samples could not be retrieved from the 12 to 18" depth at anystation in the North Disposal Site due to the presence of asubsurface layer composed of hard clay". The report also states,"sediments from several stations showed a trend of increasingmetal concentrations with depth. Station AS09 had concentrationsof 19 out of 23 TAL metals (including all the metals of concern)were higher in the 6 to 12" sediment when compared to surficial


ftR3l2U3

TABLE la. SAMPLE LOCATIONS ALONG THE CHRISTINA RIVER

SAMPLINGSTATIONS

RS01

RS01d

RS02

RS03

RS04

RS05

RS06

RS07

RS08

RS09f

RS10

RS11

RS12

RS13«

RS14*

RS15

PHASE I*

SW SED

PHASE II

SW SEDb

X

X

X

X

X

X

PHASE III

SW BIO

X

X

X

X

X

X

X

SEDb

X

X

X

X

X

X

X

SUPP.PHASE III

SW

X

X

BIO

X

X

X

X

X

X

X

SEDe

X

X6

X

X

X

X

Xe

NOTES:

a. No Phase I data results were available.b. Sediments collected at depths of 0-6".c. RS01 relocated.d. Sediments collected at depths of 0-6" and 6-12" except where noted.e. Sediments collected at 3 depths: 0-6", 6-12", and 12-18".f. White Clay Creek Station.g. Wetland Stations.SW - Surface WaterSED - SedimentBIO - Biota

AR3I2UI*

TABLE Ib. SAMPLE LOCATIONS IN THENORTH DISPOSAL SITE WETLANDS

SAMPLINGSTATIONS

AS06

AS07

AS08

AS09

AS10

ASH

AS12

PHASE I*

SW SED

PHASE II

SW

X

X

X

SED

X

X

X

X

PHASE III

SW

X

BIO SED

X

X

X

X

SUPP.PHASE III

SW

X

X

BIO

X

X

X

X

X

SEDb

X

X

X

X

X

TABLE 1C. SAMPLE LOCATIONS IN THESOUTH DISPOSAL SITE WETLANDS

SAMPLINGSTATIONS

AS01

AS02

AS03

AS04

AS05

PHASE I*

SW SED

PHASE II

SW

X

X

X

SED

X

X

X

X

X

PHASE III

SW

X

X

BIO

X

X

SED

X

X

SUPP.PHASE III

SW

X

X

BIO SEDb

X6

X

X

NOTES:

a. No Phase I data results were available.b. Sediments collected at depths 0-6" and 6-12" except where noted.c. Sediments were collected at 3 depths: 0-6", 6-12", and 12-18".SW - Surface WaterSED - SedimentBIO - Biota

AR3I2U5

TABLE 2. SUPPLEMENTAL III SEDIMENT SAMPLE LOCATION DEPTHS

NOTES:

a. RS01 relocated.

SAMPLINGSTATIONS

RS01'

RS07

RS11

RS12

RS13

RS14

RS15

AS01

AS03

AS05

AS06

AS07

AS08

AS09

AS12

DEPTH OF SEDIMENT SAMPLES0-6" 6-12" 12-18"

X

X

X

X

XX

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

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Figure 2. Christina River Sampling Locations

'"Wk- ~.i»*'•*". r,•Ah&drt/.

*?/*-. w m

Map not to scaleLEGEND;

• RIVER SEDIMENT SAMPLING LOCATION

Woodward-Clyde ConsultantSAP SOURCE: (7 Sept 1 90)BASE MAP TAKEN FROM U.S.G.S. 7.5 MINUTE OUAOSERIES. -NEWARK. EAST DELAWARE - NEW JERSEY*DATED 1BS3. PHOTOREVISED 1985 AND *WILMINGTON,SOUTH. DELAWARE-NEW JERSEY* DATED 1967.PHOTO-REV.SED 1987. j»R 3 | 2 I 6 U

Figure 3. North Disposal Site Sampling Locations

DuPONTPROPERTY1 -10N

AC -4- . WETLAND SAMPLING STATIONSIAS-ii. -*_- - DuPONT - NEWPORT SITE

^. " NEWPORT, DELAWARE100 200 FT

-01 SURFACE WATER SAMPLING LOCATION SCALE

AS -01 SEDIMENT SAMPLING LOCATIONi

v SfSSKSmSS 10"" K°fvard;!;l e Consu1tants SR3I2I65

Figure 4. South Disposal Site Sampling Locations

VE LAND SAMPLING STATIONSuuPONT - NEWPORT SITENEWPORT, DELAWARE rv-

AW-01 SURFACE WATER SAMPLING I100 .200 FT i

AS-01 SEDIMENT SAMPLING LOCATIONI

FIELD CHECKED WETLAND BOUNDARY, ,. ,«^«v /* "N FJELD CHECKED WETLAND B0Woodward-Clyde Consultants (7 Sept 19SO) (___J (NORTH.ANOspurRSffa


sediments. Other stations where subsurface concentrations of themetals of concern are higher than those at the surface include:AS08, for Arsenic, Barium, Copper, Lead, Mercury, and Zinc; AS07for Barium, Cadmium, Copper, Lead, and Nickel; RS13 for Cadmium,Chromium, and Nickel; RS14 for Chromium and Nickel; and AS06 forBarium" (DSR Section 4.3.2, p.4-11).

The areal extent of contamination was never clearly defined inthe RI or EE reports. Chemical concentration maps presentingchemical concentrations and locations, or chemical concentrationcontour maps depicting gradients of the cited chemicals were notfound.

6.5 Sample Location Validity and ComparabilitySampling protocols, sample quality criteria, sampling locationdescriptions or photographs, and other pertinent quality controldaca were not readily available for review. Some generalitiesabout the sampling locations were included in the RI, however,the actual sampling point locations were never really describedor characterized in a manner that could be interpreted. It isknown that the EPA did approve of these sampling location points,however this does not dismiss the investigators from documentingand characterizing these areas in a manner that is normallyassociated with the Remedial Investigation protocol. Therefore,it could not be determined whether or not these sampling locationpoints were valid, which in turn does not impart the ability tocompare data results.

6.6 ConclusionsIt is generally incomprehensible as to how conclusions .can bedrawn from data that is so acutely disorganized. WCC haveprovided data that indicate surface waters, sediments and biotahave been impacted, but to what extent these media and biota havebeen impacted has not yet been determined. This is due primarilyto both the disorderly data presentation and data gaps.

From this review, it seems apparent that:

o There are enough data to indicate that the Site is contributingmetal concentrations to the Christina River above the degradedconditions associated with other non-Site sources locatedupstream,

o Completeness and adequacy of collected data is notsubstantiated by WCC,

o The summary and presentation of collected data is nearlyuninterpretable, and


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DRAFT DuPont Ne\qport Site Review; Review of Ecological Concerns______

o Sample data locations, constituents and frequency are notclearly justified or documented to characterize the natureextent and rate of chemical releases.



Chapter 7CONCLUSIONS

An integration of all previous environmental assessments andinvestigations is necessary to .fully characterize the ecologicalimpacts and to evaluate the potential human health risks at andnear the Site. Many studies and technical documents have beencompleted by WCC from the period of 1987-1991 addressing theextent of distribution and the source of the Site-relatedchemical constituents. However, the conclusions drawn by WCC inthe RI are not in complete concurrence with the latest reviewcomments made by EPA, STAG, U.S. Fish and Wildlife Service(USFWS), and Dynamac Corporation. The major concerns expressedby these groups are:(1) the choice of the reference station location,(2) identification of the site-related contaminants of concernand,(3) the need for further evaluation of the site-relatedimpacts to the biotic community and the associated human healthrisks from the contaminants of concern. These comments have beenincorporated into the appendices of this report and must beaddressed in a revised Remedial Investigation Report by WCC.

New conclusions will have to be developed by WCC based on a re-evaluation of the above criteria and its affect on the previouscharacterization of the site environmental and health riskassessments.

7.1 Contaminants of Concern(Chapter 3 of this report)

o COC selection for the EE has been inappropriately based onconsideration of contaminant levels in sediments withoutconsideration of prevalence of contaminants in soil, surfacewater or biota

\

o The order of magnitude criterion part of the COC selectionrationale for inclusion in the list of COCs has no mathematicalor scientific basis. Use of this criterion has led to failureto include cadmium and chromium as COCs for all areas of thesite.

o Discussion of the extent of PCE, TCE and PAH contamination atthe site is missing from the EE.


DRAFT DuPont Newport Site Review; Review of Ecological Concerns_______________________

7.2 Reference Condition(Chapter 4 of this report)

o WCC has used comparisons between RS15 (a contaminated upstreamreference station) and site wetlands to reach conclusions aboutsediment and benthic community quality in the wetlands. Thesecomparisons have been incorporated in the sediment qualitytriad analyses for the wetlands (Figures 6 and 7, EE). Use ofRS15 to assess the quality of the wetlands is inappropriatebecause the wetlands and drainageways are not subject to theupstream sources of contamination which are affecting RS15.Based on the site history presented in the EE and relateddocuments, all contamination of the site wetlands is the directresult of waste disposal practices at the DuPont facilitybetween 1900 and 1974. Before operations began at the site in1900, the area was pristine. Therefore the wetlands anddrainageways need to be compared to a pristine referencecondition; either an uncoritaminated wetlands or literaturevalues.

o An insufficient number of samples (two) were collected tocharacterize the quality of wetlands sediments using thesediment triad approach.

o Normalization of sediment contaminant levels to calcium is notinformative for the sediment triad analysis. The normalizationprocedure is designed to yield information about the relativebioavailability of contaminants in sediments. Since calciumconcentrations are unrelated to either the physical/chemicalnature of the sediments or to the relative bioavailability ofmetals in sediments, normalization to calcium will tend toobfuscate rather than elucidate sediment quality trends.

o Fallacious reasoning has led to the conclusion that metals inSouth Disposal Site soils are not bioavailable.

»

7.3 Site Ecosystem Characterization(Chapter 5 of this report)

o No wetland delineation reports.

o Impacts to Wetlands/Water movement in Wetlands not determined.

7.4 Nature and Extent of Contamination(Chapter 6 of this report)

It is generally incomprehensible as to how conclusions can be


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DRAFT DuPont Newport Site Review; Review of Ecological Concerns__________________

drawn from data that is so acutely disorganized. WCC haveprovided data that indicate surface waters, sediments and biotahave been impacted, but to what extent these media and biota havebeen impacted has not yet been determined. This is due primarilyto both the disorderly data presentation and data gaps.

From this review, it seems apparent that:

o There are enough data to indicate that the Site is contributingmetal concentrations to the Christina River above the degradedconditions associated with other non-Site sources locatedupstream,

o Completeness and adequacy of collected data is notsubstantiated by WCC,

o The summary and presentation of collected data is nearlyuninterpretable, and

o Sample data locations, constituents and frequency are notclearly justified or documented to characterize the natureextent and rate of chemical releases.



Chapter 8RECOMMENDATIONS

8.1 IntroductionThe following recommendations are based upon a review of thevarious RI phases of the Dupont-Newport site. They are derivedfrom the conclusions presented in the chapters above.

8.2 Recommendations specific to contaminants of concern(Chapter 3 of this document)

o Consider all exposure media in selecting COCs for the site (notsediments only).

o Compare contaminant levels to standards: drop arbitraryrequirement for order of magnitude excess of standards to beincluded on list of COCs.

o Evaluate PAH, TCE, and PCE as potential COCs.

o Be consistent throughout sampling media in establishment ofcriteria for contaminants of concern (COC). For example, anycompound above reference levels and guidelines would qualify asa COC.

o Consider the following factors, in addition to those detailedin the EE, in the discussion of the rationale behind selectionor rejection of each COC per sampling media: (1) mobility ofchemicals; (2) bioavailability; and (3) potential tobioaccumulate.

o Employ the criteria listed in Table 12 in the evaluation ofsediments throughout the EE.

o Include cadmium and chromium as contaminants of concern.

8.2 Recommendations specific to reference condition selection(Chapter 4 of this report).o Do not use the contaminated upstream river station RS15 as areference condition for non-riverine sediment stations for thesediment triad analysis or to support any other conclusionsexcept the incremental contribution of the DuPont site to rivercontamination.

o Justify use of AS12 as a reference condition for wetlands


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sampling stations.

o If AS12 is not contaminated, redo sediment triad analysis forwetlands stations using AS12 as the reference conditionthroughout.

o Redo sediment triad analysis without calcium normalization.Normalize sediment contaminant levels to a physical/chemicalcharacteristic of the sediments that is related to metalbioavailability; alternatively, do not normalize sedimentcontaminant concentrations.

o Refrain from attempts to downplay the significance of dataindicating .site-related toxic effects may be occurring, such asthe reduction in relative benthic abundances in near-riverstaions.

o Collect additional sediment triad samples from the SOuthDisposal site wetlands.

8.3 Recommendations specific to site ecosystem characterization(Chapter 5 of this report).

o Provide qualitative maps showing all past sampling locationsfor soil (surficial and subsurface), sediments, groundwater,surface water and biological sampling for the Site. It isrecommended that tables be prepared incorporating all thesampling parameters and analytical results in a concise manner.More comparison tables are needed to fully understand all dataacquired (see Table B-4). It is recommended that a siteecosystem map be developed incorporating topographical featureswith contour intervals, surface waters, wetlands, vegetationtypes, visual biotic stress, DuPont property line and adjoiningland uses (ie. wetland, industrial, residential, etc.).

o Investigate the possibility that the area around RS-13 and RS-14 is not the only drainage pathway for the North DisposalSite.

o Provide an ecological map indicating observable vegetativestress.

o Clarify to what extent field verification of wetlanddelineation was performed. Appropriate field verificationwould include hydric soil determinations and hydric soilmapping, plant transect identification, indicator group (ie,OBL, FACW, FAC, and UPL) and number/types of plant occurrencesalong the transect, hydrological evaluations and otherjustification for wetland boundary lines.



o Delineate and characterize for off-site migration areas fowetlands and drainage pathways southwest of the North DisposalSite which provide surface drainage from the site

o Provide a more comprehensive characterization of the wetlandsdowngradient from the North and South Disposal Sitedrainageways.

o Investigate bioaccumulation and bioconcentration in area westof North Disposal Site and surrounding wetland areas.

o Evaluate potential risks to terrestrial receptors from exposureto lead.

o Conduct a terrestrial ecological risk assessment for the Northand South disposal sites, including

1) receptor identification,2) exposure scenario development,3) quantitative or qualitative estimation of dose received,4) dose-response relationship characterization, and5) risk characterization.

o Collect fish samples from a number of locations along the riverin order to allow an evalxiation of site impacts on fishcontamination levels.

o Consider fish and their non-human predators as targets fortoxic effects of COCs.

o Collect unfiltered water samples from locations along theChristina River to facilitate evaluation of the contribution ofsite COCs to river contamination.



8.4 Recommendations specific to nature and extent ofcontamination(Chapter 6 of this report).

o Perform surface water sampling

o Clearly justify and document sample data locations,constituents and frequency.



REFERENCES

Biological Technical Assistance Group. (BTAG). 1991a. Letter fromRobert Davis, BTAG, to Randy Sturgeon, USEPA III. December 11,1991.

Biological Technical Assistance Group. (BTAG). I991b. Letter fromRobert Davis, BTAG, to Randy Sturgeon, USEPA III. December 5,1991.

Delaware Department of Natural Resources and EnvironmentalControl. 1991.

Delaware Department of Natural Resources and EnvironmentalControl. 1990. State of Delaware Surface Water QualityStandards, DNREC, Division of Water Resources, Dover, Delaware.

Delaware Department of Natural Resources and EnvironmentalControl. 1988a. Delaware Water Quality Inventory, Vol. IllTechnical Appendix.

Delaware Department of Natural Resources and EnvironmentalControl. 1988b. A Synoptic Report on Toxic SubstancesContamination of Red Clay Creek.

Delaware Department of Natural Resources and EnvironmentalControl. 1987.

Dynamac Corporation. 199la. Ecological Assessment GuidanceDocument. RCRA Facility Investigation/Corrective MeasuresStudy.

Dynamac Corporation. 1991b. Letter from Camille Costa, DynamacCorporation, to Randy Sturgeon, USEPA III. November 27, 1991.

Dynamac Corporation. 1991c. Letter from Camille Costa, DynamacCorporation, to Randy Sturgeon, USEPA III. November 6, 1991.

Eisler, R. 1987. Mercury Hazards to Fish, Wildlife, andInvertebrates: A Synoptic Review. U.S. FWS Biol. Rep.85(1.10).

Eisler, R. 1986. Chromium Hazards to Fish, Wildlife, andInvertebrates: A Synoptic Review. U.S. FWS. Biol. Rep.85(1-6) .



Greene, R. 1988. Delaware Department of Natural Resources andEnvironmental Control. Personal communications and unpublisheddata on file at Dover, Delaware.

Long, E.R. The Use of the Sediment Quality Triad inClassification of Sediment Contamination. IN ContaminatedMarine Sediments: Assessment and Remediation. National AcademyPress, 1989.

Lowe, T.P., T.W. May, W.G. Brumbaugh and D.A. Kane. 1985.National Contaminant Biomonitoring Program: Concentrations ofSeven Elements in Freshwater Fish, 1978-1981. Arch. Envl. Cont.and Tox. 14:363-388.

Ontario Ministry of the Environment. 1989. Development ofProvincial Sediment Quality Guidelines.

Shacklett, H.T. and J.G. Boerngen. 1984. Element Concentrationsin Soils and Other Surficial Materials of the ConterminousUnited States. U.S.G.S. Professional Paper 1270.

Simpson, R.L., R.E. Good, B.J. Dubinski, Pasquale, and K.R.Philipp. 1983. Fluxes of Heavy Metals in the Delaware RiverFreshwater Tidal Wetlands, Final Report; Center for Coastal andEnvironmental Studies, Rutgers, New Brunswick, New Jersey.

U.S. Army Corps of Engineers. 1976. Great Lakes Sediment AnalysesConducted for EPA Region IV.

U.S. Environmental Protection Agency, Region III. (USEPA III).1991a. Randy Sturgeon, USEPA III, to Joel Karmazyn, E.I. DuPontde Nemours and Company, Inc. December 16, 1991.

U.S. Environmental Protection Agency, Region III. (USEPA III).I991b. Randy Sturgeon, USEPA III, to Joel Karmazyn, E.I. DuPontde Nemours and Company, Inc. September 10, 1991.

U.S. Environmental Protection Agency, Region III. (USEPA III).I989a. Rapid Bioassessment Protocols for Use in Streams andRivers. Benthic Macro-invertebrates and Fish. Office ofWater. Washington, DC. EPA/440/4-89-001.

U.S. Environmental Protection Agency, Region III. (USEPA III).1989b. Risk Assessment Guidance for Superfund, Volume IIEnvironmental Evaluation Manual. Office of Emergency andRemedial Response. Washington, DC. EPA/540/1-89/001.

U.S. Environmental Protection Agency, Region III. (USEPA III).1986. Quality Criteria for Water. Office of Water Regulations


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and Standards. EPA/440/5-86/001

U.S. Environmental Protection Agency, Region III. (USEPA III).1985. National Perspective on Sediment Quality. Office of WaterCriteria and Standards. EPA Contract No. 68-01-6986.

Woodward-Clyde Consultants. 1991a. Draft Risk Assessment for theDuPont Newport Site. Volume I Environmental EvaluationReport. July 30, 1991. Volume II Human Health Evaluation.October 14, 1991.

Woodward-Clyde Consultants. 1991b. Letter from Ceil Mancini,Woodward-Clyde Consultants, to Randy Sturgeon, USEPA III.October 14, 1991.

Woodward-Clyde Consultants. 1991c. Phase III RemedialInvestigation for the DuPont Newport Site. May 17, 1991.

Woodward-Clyde Consultants. 1991d. Remedial Investigation forthe DuPont Newport Site. November 1, 1991.

Woodward-Clyde Consultants. 1991e. Supplemental Phase IIIWetlands Investigation for the DuPont Newport Site. May.

Woodward-Clyde Consultants. 1990. Phase III WetlandsInvestigation for the DuPont Newport Site. January.

Woodward-Clyde Consultants. 1989. Phase II WetlandsInvestigation for the DuPont Newport Site. March 23, 1991.


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dupont- newport site reviewthe dupont-newport superfund site is located south of newport, delaware,...

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