response to 2/20/07 comments on bedrock & … · 350 eagleview boulevard suite 200 exton, pa...

SDMS DocID 2091424

11 June 2007 Reference: 0057238

Kelley A. Chase, Remedial Project Manager Hazardous Site Cleanup Division Eastern Pennsylvania Remediation Branch (3HS21) U. S. Environmental Protection Agency, Region III 1650 Arch Street Philadelphia, PA 19103-2023

Re: Response to Comments North Penn Area 5, Operating Unit 2 (NP5 0U2)

Dear Ms. Chase:

On behalf of Stabilus and Honeywell International Inc. (Honeywell), Environmental Resources Management (ERM) has prepared the following response to the U.S. Environmental Protection Agency's (EPA's) 20 February 2007 comments on Bedrock and Bioremediation Memorandums dated 30 November 2006 for the North Penn Area 5 Operating Unit 2 (NP5 OU2). Additionally, included herein is additional information requested by EPA during a teleconference call on 20 March 2007 and a technical meeting at the site on 15 May 2007. The EPA comments/requests are listed below in bold italic text, followed by ERM's response in normal font.

Environmental Resources Management

350 Eagleview Boulevard Suite 200 Exton, PA 19341 (610) 524-3500 (610) 524-7335 (fax) www.erm.com

ffi ERM.

20 FEBRUARY 2007 COMMENT LETTER

Comment 1

AlthougJt our review has generated several comments, EPA finds that the proposed bedroclc investigation and the proposal regarding bioremediation of the overburden area generally reflect our discussions a t the August 10,2006 and September 20,2006 meetings. As discussed, any proposal to treat contamination in the overburden via enhanced bioremediation must provide adequate controls to assure that possible incomplete degradation of volatile organic compounds in the overburden does not result in an increase in vinyl chloride concentrations in the underlying bedrock aquifer.

AR304754

http://www.erm.com

Ms. Kelley Chase Environmental 0057238.0001 Resources 11 June 2007 Management

Vinyl chloride is a natural degradation product of bioremediation. Vinyl chloride will be generated during the bioremediation of its parent compoimd trichloroethene; however, bioremediation will not accumulate vinyl chloride in the subsurface. The results of the microcosm studies clearly demonstrate that vinyl chloride is expected to biodegrade to concentrations below its MCL. Vinyl chloride will be degraded, but may be slower then observed in the microcosm studies, but will still degrade within a natural setting. Accumulation of vinyl chloride is uncommon because it has numerous degradation mechanisms including both biotic arid abiotic oxidation in an aerobic environment and direct degradation or reductive dechlorination in an anaerobic environment (ITRC, December 2001). In addition to the above, generating a vinyl chloride plume capable of evolving on its own is not possible considering:

• Current TCE plume is stable or shrinking.

• Limited size of the area targeted for remediation.

• Amount of vinyl chloride generated by TCE biodegradation is approximately 50% of TCE mass.

As documented in the literature, if vinyl chloride reductase enzymes are present within the bioaugment material, vinyl chloride will not accumulate. As a precaution, the bioaugment material should be tested for the vinyl chloride and cis-l,2-dichloroethene reductase enzymes to ensure they are present prior to injection. Additionally, the aquifer should be analyzed for their presence prior to injection of the bioaugment material as well as after injection. Vinyl chloride should also be analyzed with the other degradation products from TCE (i.e., cis-l,2-dichloroethene, vinyl chloride, ethene, and ethane), as well as other parameters. Monitoring wells near the proposed remediation area in the downgradient directions should be monitored for these degradation products and one or two wells within the target remediation area should be analyzed for the cl2DCE and VC reductase enzymes. Further details of the contingency monitoring and steps to address an above anticipated observation or extended delay in degradation of vinyl chloride can be addressed in the work plan for the bioremediation remedy.

Comment 2

In considering issuance of a revised PRAP for OU2, in conjunction with the existing sampling data contained in the Site Administrative Record, EPA will evaluate all relevant information submitted by Stabilus and Honeywell, including information pertaining to the use of enhanced bioremediation, that

AR304755


was not available during preparation ofthe July 2002 Feasibility Study and subsequent PRAP. Specifically, the Superfund statute and regulations require EPA to assess potential remedies against the following criteria found in the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) at 40 C.F.R. §300.430(e)(9)(iii):

1. Protection of human health and the environment;

2. Compliance with applicable or relevant and appropriate requirements

(ARARs);

3. Short-term effectiveness;

4. Reduction of toxicity, mobility, and volume through treatment;

5. Long-term effectiveness and permanence;

6. Implementabllity;

7. Cost;

8. State acceptance; and

9. Community acceptance.

A considerable amount of work has been done by Stabilus and Honeywell subsequent to the preparation of the July 2002 Feasibility Study (FS) to support the selection of enhanced in situ bioremediation (EISB) as the best remedy. That work includes:

• Bioremediation Evaluation for 0112 letter dated 4 June 2003

• Ground Water Sampling Report - Task 1 ofthe Bioremediation Evaluation dated December 2003;

• Bioaugmentation Microcosm Study Report - Task 2 ofthe Bioremediation Evaluation dated June 2004;

• New Developments in Response to Roy Schrock's Letter on the Bioremediation Study letter dated 20 October 2004;

• Addendum to June 2004 Bioremediation Microcosm Study Report letter dated 12 November 2004;

• EPA Meeting: Bioremediation Discussion on 10 November 2004;

• Site Meeting with EPA and ERM on 21 July 2005;

• EPA Meeting: Project Update Meeting on 10 August 2006;

• Technical Meeting with EPA and ERM on 20 September 2006;

AR304756


• Bioremediation Memorandum dated 30 November 2006;

• Technical Teleconference Meeting with EPA and ERM on 20 March 2007; and

• Site Meeting with EPA and ERM on 15 May 2007.

The results of the studies performed by Stabilus and Honeywell were summarized during a presentation to EPA on 10 August 2006. In short, the studies showed:

• Tricloroethene and cis-1,2-dichloroethene converted to vinyl chloride and ethene < 100 days;

• After 118 days, vinyl chloride showed a clearly decreasing trend; and

• At 314 days, vinyl chloride undetectable.

As demonstrated to EPA during a presentation regarding bioremediation on 10 November 2004, the bioremediation remedy meets the above EPA Remedial Alternative Evaluation Criteria. The points presented in the 10 November 2004 presentation were presented as follows:

1. Protection of Human Health and the Environment

o Bioremediation will reduce the TCE concentrations and the potential risk to human health and the environment, and enhance ongoing natural attenuation.

2. Compliance with applicable or relevant and appropriate requirements (ARARs)

o Bioremediation will comply with applicable ARARs (designed to achieve MCLs in overburden groimd water in area targeted for remediation).

o Bioremediation and injection of biostimulants and bioaugments will comply with the requirements of a UIC permit. A permit equivalency submittal should not be necessary and is assumed that RPM approval is sufficient.

3. Short-Term Effectiveness

o Implementation of bioremediation will not increase the potential health risk to community and/or on-site workers.

o No environmental impacts are expected from bioremediation implementation.

AR304757


o Bioremediation is expected to achieve cleanup goals in targeted area within 5 years.

4. Reduction of Toxicity, Mobility, or Volume

o Bioremediation will reduce the toxicity, mobility, and volume of TCE and its daughter products.

5. Long-Term Effectiveness and Permanence

o Residual risk associated with treatment residuals in the area targeted for remediation is low considering bioremediation is a destruction technology and will achieve cleanup goals.

o For bedrock groimd water, there is no need for additional controls to protect community assuming the plume remains stable or decreases in size, property use remains nonresidential, and ground water not used as a potable water source.

6. Implementability

o Bioremediation using direct-injection method is readily implemental technology using commercially-available equipment and materials.

o Performance monitoring will be accomplished by routine ground water monitoring.

7. Cost

o Technology is cost effective compared to ground water pump and treat alternative.

8. State Acceptance

o No concerns anticipated.

9. Community Acceptance

o No concerns anticipated.

o Bioremediation identified by the public as potential technology at August 2002 public meeting.

AR304758


Comment 3

Please submit any supporting documentation, including cost estimates, that you believe should be considered in EPA's evaluation ofthe proposed remedy against the above criteria.

Per further discussion with EPA during a 20 March 2007 teleconference meeting, the EPA requested that the cost estimates within the PRAP for NP5 OU2 be updated to include bioremediation. As noted during the 15 May 2007 site meeting, these estimates are only for the overburden groundwater on the former Stabilus property and limited to a comparison of in situ chemical oxidation (ISCO) and bioremediation. As requested these costs were updated and the two technologies were estimated based on similar criteria. Table 1 is a summary of the results of the revised cost estimates. The remediation area for both scenarios was estimated to be 56,000 ft̂ based on the 100 ppb concentration contour as shown on Figure 7. Additionally, EPA had assumed a 10 year remediation horizon for ISCO. Though, bioremediation can be expected to meet the remedial objectives in 5 years, for the purposes of comparison and to be conservative, a 10 year horizon was also assumed for bioremediation. Based on these estimates bioremediation is the preferred remedy.

An example summary of the bioremediation remedy to be used in the PRAP is as follows:

The bioremediation alternative includes control/reduction measures for the area of maximum TCE concentrations in shallow groundwater. The goal of this is to reduce contaminants below relevant MCLs. It is estimated that contaminant levels will fall below MCLs within a period of 5 years.

In-situ control/reduction measures would be applied to the overburden/shallow aquifer system, in areas which contains the highest concentrations of TCE in the groundwater, and also includes associated soil contamination within the capillary fringe and shallow groundwater. The area where restoration remediation efforts will take place at the former Stabilus property is depicted on Figure 7. For this alternative, control measures for TCE in soil will be enhanced in situ bioremediation (EISB).

EISB systems designed to remediate chlorinated solvents in groundwater involve input of a biostimulant (e.g., organic source, nutrients, and electron acceptors) and a bioaugment (i.e., microbial cultures) to stimulate

AR304759


degradation. EISB systems may be used to remediate high concentrations areas within plumes or areas of elevated concentrations and to help provide containment of a chlorinated solvent plume. EISB converts the contaminants into the harrrJess byproducts of carbon dioxide and water. At the former Stabilus property, the EISB process should be designed to convert the pollutant TCE to carbon dioxide and water as it is degraded by the microbial cultures. EISB would involve three phases, a primary injection of biostimulant, a secondary injection of biostimulant and an injection of the bioaugment material.

20 FEBRUARY 2007 COMMENT LETTER - BEDROCK MEMORANDUM

Comment 1

Page 1. The cross-sections drawn do not have lithologic and fracture information and bedding correlations. This type of interpretation is import to the location and depth ofthe new wells. Please add this information to the cross-sections. Additionally, new cross-section should be created l)for the down-dip direction, and 2) for A-A' which is coincident with strike.

There is no disagreement that it would have been desirous to add more lithologic information to the cross-sections. However, this effort was significantly hindered by the Remedial Investigation Report (prepared for EPA by Tetra Tech) not having detailed geologic information from any of the RW-, MW-,A - and W- series wells available for review. As discussed in the 30 November 2006 memo, ERM reviewed PADEP files in an attempt to garner this information. However, well logs were not attached to the reports in PADEP files either. The only information available for these wells was total well depth, depth to bedrock, and well construction specs as provided on the tables attached to the RI Report. A summary table of the type of information available for each well at the former Stabilus or BAE facility (as well which wells were logged geophysically) is attached hereto as Table 2.

Available information was utilized where possible on the cross-sections, including the fracture information from the Rl-series wells and the geophysical report by USGS (for RI-1 to RI-20). But the large number of non Rl-series wells required to establish the cross-sections made meaningful correlation across any significant distance impossible.

AR304760


Cross-sections A-A' and B-B' are prime examples, as the majority of the bedrock wells along these sections (actually all for B-B') are non- RI series wells. For C-C, only RI-6, RI-9, and RI-27 have detailed geologic information. However, even in this case, meaningful lithologic correlation was not possible since, given the dip of the formation, the individual beds at each well location would stratigraphically project above or below the interval in which the next nearest well was set.

Based on the 20 March 2007 conference call with EPA, two new cross-sections have been provided and reviewed with EPA during the site visit of 15 May 2007. These include sections D'-D (along bedrock strike but further to the southeast of A'-A) and E'-E (directly along the maximum dip direction). In addition, all figures have been revised to show the area of maximum TCE concentrations in soil. These figures are included within Attachment B.

Comment 2

Page 2. It is stated here that bedrock data gaps may exist a t the former Stabilus facility in the potential down-gradient direction and in areas northeast and southeast of the former Stabilus facility. Please provide a rationale for the data gaps in areas northeast and southeast of the facility. Please explain the "potential" down-gradient direction.

As clarified with EPA during the 20 March 2007 teleconference, the bedrock data gaps described as being northeast and southeast of the former Stabilus facility should have been noted as being to the northwest and southwest. It is for this reason the new monitoring wells described herein are located in the positions as indicated on the attached drawings.

The term "potential down-gradient" refers to the fact that there are two interpreted ground water flow directions based on aquifer anisotropy. The USGS model predicts flow to the northwest (RI-33 and RI-27 well nests) and ERM's model predicts flow nearly due east (RI-34 and RI-35 well nests). The difference in the modeled ground water flow directions is due to the potential degree of aquifer anisotropy assumed for either model.

It is also stated here that RI-33I will be completed at a depth which corresponds to the estimated depth that a bedding plane would intersect this location. Please provide the significance of "a bedding plane".

AR304761


References to "a bedding plane" do not refer to any specific, known site feature. Rather, this refers to the fact that wells further away from the area of maximum TCE concentrations in soil will, if possible, preferentially be set to monitor the same bed intervals at locations further down-dip, provided that these can be identified. Bedding plane partings are common conduits of ground water flow in bedrock settings. USGS identified likely bedding plane partings as one of two main populations of fracture sets in the Aquifer test and GW Modeling report, and a number of water bearing zones were identified as likely being bedding plane partings. As discussed with EPA at the 15 May 2007 site meeting, ground water flow along these bedding planes will be preferred monitoring intervals for proposed wells RI-34S, RI-351, RI-33I, RI-271, and RI-37I, if possible based on actual site conditions. However, final screened intervals for these wells will need to be selected based on locations of water bearing zones and data from the geophysical and packer testing.

Comment 3

Page 3. The potential source area is referred to here. Please depict this area on the figures.

Per EPA's request the area of maximum TCE concentrations (greater than 1,000 jtig/kg) in soil concentration are shown on the accompanying figures. For the purposes of clarity on the figures, this area is depicted as extending vertically through the full thickness of the overburden material; however, the concentrations in actuality are variable and likely not uniform within the entire thickness of the soil column. While the area is referred to as a potential source area, please note that groundwater concentrations of similar magnitude have been historically measured in the present vicinity of the former Stabilus facility at the time that the facility originally commenced operation.

Comment 4A

Page 4. Although the proposed geophysical work is critical to determining the flow characteristics of the fractures in the borehole, it does not provide information regarding contaminant distribution. Thus, packer interval testing for the contaminants of concern should be added to the proposed work. The chemical data, in concert with the geophysical work, will provide the information necessary to determine where to screen the wells.

AR304762


It is agreed that discrete sampling of potential impacted ground water flow zones should be conducted via packer testing. As discussed during the 15 May meeting, the packer testing should be conducted on intermediate depth wells after these wells have been drilled to target depth and the geophysical testing has been completed. In general, the intermediate depth wells at each well nest location should be drilled to the target depths indicated on the cross-sections attached hereto. These have been selected to monitor both the shallow flow zones at each location and potential preferential flow pathways (bedding planes) considering the strike and dip of the Brunswick Formation at the site. A series of geophysical tests should then be conducted, such as caliper, riatural gamma ray, fluid resistivity, temperature, heat pulse flow meter (static and pumping conditions), and optical and acoustic televiewers. The details of proposed testing will be identified in the bedrock investigation work plan. Significant fracture intervals where water was observed to likely be entering the borehole can be targeted for discrete groundwater sampling using the packer system.

As discussed during the 15 May meeting, EPA will receive results as they become available during the drilling activities, and consultation with EPA should be conducted regarding the various testing activities. Specifically, flow zones for packer testing will be selected based on the geophysical results and drilling observations. All reasonable efforts to share this data with EPA and discuss the rationale for the selected packer testing intervals with EPA should be made before the testing is conducted. Also, the final screened interval for each well will be identified in consultation with EPA (when possible) once the data from the ground water sampling efforts have been received.

Comment 4B

The potential presence of DNAPL should be noted during drilling activities and a contingency plan for encountering DNAPL should be available. Packer testing will also provide information regarding the potential presence of NAPL.

During drilling, observations of the well cuttings and fluids will be made to identify potential indicators of DNAPL, such as strong odors, sheens or separate phase liquids, and discolored fluids. If DNAPL is suspected, drilling operations will be ceased and its presence can be confirmed with the use of a oilphilic dye such as Red-dye-O. If DNAPL presence is confirmed, further drilling will not be performed at that well location. Should the deeper intervals at this location still require monitoring, the nested well should be

AR304763


Steel cased to a point below where the DNAPL was encoimtered during installation.

Water confirmed to contain DNAPL should be containerized separately from the other well fluids. Disposal requirements for this water will be determined based on sampling of the containerized water at the close of the drilling operations.

Comment 5

Figures 1 and 5. I t would be very helpful if dip and strike were depicted on theses figures.

The requested information has been added to these figures.

General Comment

The information requested above (comments 1-3 and the figures) should be provided prior to finalizing the proposed locations ofthe new wells.

Per EPA's request, these figures were provided to EPA during a subsequent meeting on 15 May 2007. Based on the results of this meeting, the locations of the wells are now depicted on the attached Figures.

20 FEBRUARY 2007 COMMENT LETTER - BIOREMEDIATION MEMORANDUM

Comment 6

A comparison ofthe proposed area in ERM's November 30,2006 submittal to the area we discussed a t the September 20,2006 meeting indicates that the two areas are very similar. I t appears that the proposed area may be slightly less to the east than the area previously discussed in the meeting; however, this may be clarified using surveyed points and the 100 ppb concentration contour.

Agreed. Per EPA's request during the 20 September 2006 meeting, the 100 ppb concentration contour was used to estimate the potential zone of injection. As depicted within the 30 November 2006 submittal, the estimated zone varied slightly.

AR304764

Ms. Kelley Chase Environmental 0057238.0001 Resources

11 June 2007 Management

CLOSING

If you have any questions regarding this correspondence or any other site issues, please contact me at your convenience at (610) 524-3578.

Sincerely,

Derek W. Tomlinson Project Manager

pb /dwt

enclosures: Tables 1-2 Figures 1-7

cc: J. Bolstein, Esq. (FoxRothschild) B. Tierney (Stabilus) B. Israel, Esq. (Arnold Porter) C. French (Honeywell) R. Fender (ERM) P. Beyer, P.G. (ERM) File

AR304765

1

Figures

AR304766

tr FIGURE 1

CROSS-SECTION LOCATIONS NORTH PENN AREA 5 SITE COLMAR, PENNSYLVANIA

NOTE 1. DIMENSIONS AND LOCATION OF PARCEL ESTIMATED BASED IN THE FOLLOWING REFERENCE DRAWING: 'SITE DEVELOPMENT PLAN FOR COUNTY LINE LAND CORPORATION AND GAS SPRING CORP.', DRAWING NO. 20856 DATED 21 FEBRUARY 1979 (REVISION DATE), PREPARED BY CHARLES E. SHOEMAKER INC., ENGINEERS AND SURVEYORS OF ABINGTON, PA. \

LEGEND

VtHi^ — - —

•

(» e

A'

RAILROAD

CREEK

BEDROCK MONITORING WELL

OVERBURDEN MONITORING WELL

PROPOSED BEDROCK MONITORING WELL

CROSS.SECTION LOCATION

400 200 400

SCALE IN FEET

M L B / 0 4 - 0 9 - 0 7 ERM, INC.

AR304767

250 —

230

130/0 —

FIGURE 2 CROSS-SECTIONA'-A

NORTH PENN AREA 5 SITE COLMAR, PENNSYLVANIA

^MW.3

LocID MW3

Ma>«mum 10U

Mninnjm 10U

Average 10U

LEGEND

MONITORING WELL WITH SCREEN

J ^ _ SHALLOW BEDROCK POTENTIOMETRIC SURFACE (MAY 2003)

F FRACTURE OBSERVED BASED ON BOREHOLE GEOPHYSICS CONDUCTED BY USGS

OVERBURDEN

BRUNSWICK FORMATION (RED AND LIGHT GRAY SHALE AND SILTSTONE)

LOCATION INFERRED

HORIZONTAL SCALE IN FEET

VERTICAL EXAGGERATION IS 1SX

M L B / 0 4 - 0 9 - 0 7 ERM, INC.

AR304768

320 -1

300

260

240

i — 200

o p 180

120

100

80

60 -

40

20

MG.1B7

LocID RI23

Maximum 3600

Minimum 120

Average 16G4

AREA OF MAXIMUM TCE CONCENTRATIONS IN SOIL

FIGURE 3 CROSS-SECTION B'-B


LocID RI24

Maximum 10U

Minimum D5U

Average 6.83 U

LEGEND

MONfTORING WEa WITH SCREEN

J ^ _ OVERBURDEN WATER TABLE (MAY 2003)

' y SHALLOW BEDROCK POTENTIOMETRIC SURFACE (MAY 2003)


r I OVERBURDEN

I 1 NO LITHOLOGIC INFORMATION IS I I AVAILABLE, THIS INTERVAL IS ASSUMED TO

BE THE BRUNSWICK FORMATION

200 100

HORIZONTAL SCALE IN FEET VERTICAL EXAGGERATION IS 5X

200

MLB/04-1B-07 ERM, INC. AR304769

320

260

260

240

220

=• 200

i= 180

120

100 -

40

20

c RI-33S (PROPOSED) gTABILUS

RI.33I (PROPOSED) .̂ \ BUILDING

FIGURE 4 CROSS-SECTION C-C


C W.6

• :l

NP-75

RI-9

LocID RI9S

Maximum l O U

Minimum 10U

Average l O U

LocID RI9D

Maximum 10U

Minimum 10U

Average 10 Ll

— F

LEGEND

m MONITORING WELL WrrH SCREEN

. _ OVERBURDEN WATER TABLE (MAY 2003)

^ _ SHALLOW BEDROCK POTENTIOMETRIC SURFACE (MAY 2003)


OVERBURDEN

BRUNSWICK FORMATION (RED AND UGHT GRAY SHALE AND SILTSTONE)

200 100 200


LocID Ries

Maxr tx jn 10U

Wrimum OSU

Averaae 6.83 U

LocID RI6D

Maximum 10U

Minimum 0.5 U

Average 6B3U

LocID RI27S

Maximum 3800

Minimum 1100

Average 2033.3

/

/ . / /

/ , /

. / / /

APPARENT DIP IS CORRECTED FOR DIFFERENCE BETWEEN ORIENTATION OF

SECTION LINE vs. ORIENTATION OF MAXIMUM DIP ANGLE

Loo ID RI27D

MaMm^un 1

Minimum 0.91

Average 0.955

LocID W6

Maximum 10U

Minimum 10U

Average 10U

MLB/04-1B-07 ERM. INC. AR304770

LocID RI29

Maximum 0 5 U

Minimum 0.5 U

Average 0.5 U

LocID RI24

Maximum IGU

Minimum 05 U

Average 6.83 U

FIGURE 5 CROSS-SECTION D-D'


s

t

320-,

300-

280

260

240

220

200-

180-

160

140

m

100

D' w-12 W-10 W.9

w-17

LocID W17

Maximum 5B

Minimum 4J

Average 46

LocID W10

Maximum 10U

Minimum 10U

Average l O U

LocID W12

Maximum 10U

Minimum 10U

Average 10U

LocID

W9 MaMmum

2B Minimum

10U Average

LocID RI19S

Maximum I B

Minimum 0.6 U

Average 0.75

LEGEND


. _ WATER TABLE


] OVERBURDEN

BRUNSWICK FORMATION (RED AND LIGHT GRAY SHALE AND SILTSTONE)

NO LITHOLOGIC INFORMATION IS AVAILABLE, THIS INTERVAL IS ASSUMED TO BE THE BRUNSWICK FORMATION

>F

F

LocID RI19P

Ma>4mLin 10U

Minimim OSU

Average 6.83 U

LocID RW6S

Maximum 0.5 U

Minimum 0 5 U

Average 05 U

LocID RW6I

Maximum 05 U

Minimum 05 U

Average OSU

LocID RW6D

Maximum 0.5 U

Minimum 0.5 U

Average 05 U

40 FT. BREAK

LocID RI25

Maximum 2500

Minimum 68

Average 975.6

LocID RI18S

Maximum 120

Minimum 57

Average 894

LocID RI18D

Maximum 7 J

Minimum 0.5 U

Average 3 76

H >

— F

200 100 200

HORIZONTAL SCALE IN FEET VERTICAL EXAGGERATKJN IS 5X

MLB/04-09 -07 ERM. INC. AR304771

S20—,

2 6 0 -

220-

200 —

180-

AREA OF MAXIMUM TCE CONCENTRATIONS IN SOIL

LocID W6

Maximum lOU

Minimum 10U

Average lOU

FIGURE 6 CROSS-SECTION E'-E


LEGEND


WATER TABLE

OVERBURDEN

BRUNSWICK FORMATION (RED AND UGHT GRAY SHALE AND SILTSTONE)

100 SO 100


MLB/04-18 -07 ERM, INC. AR304772

FIGURE? PROPOSED BEDROCK MONITORING WELLS


SCALE IN FEET

MLB/04-03 -07 ERM. INC. AR304773

Tables

AR304774

TABLE 1 Overburden Groundwater Altemative Costs North Penn Area 5 Operable Unit 2 Colmar, Pennsylvania

Alternative

Operation Period Capital Cost Anrrual O&M Cost Present Worth Cost Cost Ranking (least to most expensive)

ISCO 20,000 ft̂

10 $1,550,000

$40,000 $2,050,000

2

ISCO 56,000 ft̂

10 $3,230,000

$40,000 $3,510,000

3

Bioremediation 56,000 ft̂

10 $1,580,000

$40,000 $1,860,000

1

AR304775

TABLE 2 Well Information Summary North Penn Area 5 Colmar, Pennsylvania

Well ID

A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-11 A-12 A-13 A-14 A-16 A-17 A-18 W-1 W-3 W-4 W-5 W-6 W-8 W-9 W-10 W-12 W-13 W-14 W-16 W-17 RW-1 RW-2 RW-3

RW-4S RW-41 RW-4D RW-5S RW-51 RW-5D RW-6S RW-61 RW-6D RMS RI-ID RI-2S RI-2D RI-3S RI-3D RI-4S RI-4D

Geophysics

X

X

X

X

X

X

X

X

X

X

X

Litholigic Description

X

X

X

X

X

X

X

X

Construction Information

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

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Well Depth (feet)

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

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

AR304776


Well ID

RI-5S RI-51 RI-5D RI-6S RI-61 RI-6D RI-7S RI-7D RI-8S RI-8D RI-9S RI-9D RI-1 OS RI-IOD RI-1 IS RI-1 ID RI-12S RI-12D RI-13S RI-13D RI-14S RI-14D RI-15S RI-15D RI-16S RI-161 RI-16D RI-17S RI-17D RI-18S RI-18D RI-19S RI-19D R!-20S RI-20D RI-21 Rl-22 RI-23 RI-24 Ri-25 RI-26

RI-26S RI-261 RI-26D RI-27

R!-27S RI-27D RI-28

Geophysics

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

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

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

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

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Well Depth (feet)

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

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

AR304777


Well ID

RI-29 RI-30 RI-31 MW-1 MW-2 MW-3 MWl MW2 MW4 BC-1

NP-12A NP-12B NP-12C NP-21 NP-75 NP-87 AV-1

MG-186 MG-187 MG-188

Geophysics

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

Well Depth (feet)

X

X

X

X

X

X

X

X

X

X,

X

X

X

X

AR304778

response to 2/20/07 comments on bedrock & … · 350 eagleview boulevard suite 200 exton, pa...

Documents