UNFTED STATES ENVIRONMENTAL PROTECTION AGENCYREGION III

841 Chestnut BuildingPhiladelphia!, Pennsylvania 19107-4431 i

i

JAN 12 1994Mr. Scott McEwen |CH2M Hill I. 'P.O. Box 4400 !.Reston, Virginia 22090-1483 j

Re: Comments on the draft RI/FS Work Plan(November 1993 Version) iNorth Penn Area 12 Superfund Site !Worcester, PA 1

!Dear Scott: |

Enclosed are comments on the latest draft RI/FS work planfor the North Penn Area 12 Superfund Site. Attached^ are commentsfrom Barbara Rudnick, EPA Geologist; Dawn loven, EPA|Toxicologist; and Barbara Bloomfield, Pennsylvania Department ofEnvironmental Resources (PADER) Site Manager. Listed below aremy questions and comments:

i

1. page 3-16, list on-site incineration as a possible treatmenttechnology for soil. Also, mention water treatment as apossible remedial technology to address possiblescontaminated surface water. j

t

2. page 3-17, because its been about two years since theresidential wells have been sampled, except for those thathave been retrofitted with carbon filters, we shouldconsidered a more comprehensive round of residential wellsamples.

3. page 4-5, 6th bullet item, will VOC analysis other than thatmentioned be accomplished using RAS requests?• • . • I .

4. page 4-11, 1st paragraph and page 4-12, 1st bullet item,these dates should be changed to be consistent with the newschedule dates. j . .

5. page 4-17, 1st paragraph, 5th line, change "reduced" to"receive".. i

6. Figure 4-2, wells 17-46, 17-52, and 15-3 (Bonkowski) shouldbe marked as wells that have been provided withj carbonfilters. Then reconsider if these wells shouldj be sampledsince it is stated that wells with carbon filters are not tobe sampled. !

i9. Table 4-4, the location of blocks No.11 and No.; 14A should

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be specified in Figure 4-2. !

10. page 4-26, will the portable GC specified for the soilsampling be used in conjunction with the ARCS mobile labunit? If so, specify that it is.

11. page 4-27, EPA has made arrangement with USGS to do thegeophysical well logging at wells MW-12 and T-e!. USGS willalso do the water level measurement survey of all themonitoring wells. i •

Ii

12 i pages 4-43 and 4-44, there appears to be some t!ext missingbetween these two pages.

13. page 4-44, last bullet, does the cost for the air stripperrental include the cost of carbon regeneration/disposal? Ifnot, include such in the cost estimate. \

'< ' 1i

14. page 4-47, 2nd paragraph, 2nd line, change "isdpach" to"isopleth".

15. Figure 5-1, those schedule items that represent EPA reviewshould be for a duration of 30 days. Adjust the scheduleaccordingly. [

Bob Davis, EPA Biologist and representatives from theDepartment of the Interior and Fish and Wildlife Service havereviewed the work plan and provided me with verbal comments.Written comments will be submitted in the near future and will bepassed on to you as soon they are received. In order to expeditethe revisions to this work plan, the comments that were conveyedto me are listed below: I

I . • ' : i

1. The surface water and sediment sampling should beconducted 2 to 3 days after a rain event rather thanduring the rain event. This will provide jbetterrepresentative samples and allow for easier planning.

2. Include grain size analysis as a parameter for thesediment sample. !

i •3. As part of Task Fl.FB, in addition to identification of

vegetation and soils, include the identification ofbiota as part of the wetlands reconnaissance effort.

4. During the pumping tests, observe and record the effectof such tests on the wetlands. i

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5. If the wetlands could be potentially affected by aproposed pump and treat remedial action, then allsensitive environs must be identified and ievaluated,not only endangered species.

AROOOU3:

EPA's comments on the proposed budget will be presented toCH2M Hill after all technical issues are resolved to avoidduplicate review effort. Please call me at your earliestconvenience to arrange a meeting to discuss the attachedtechnical comments at (215) 597-8257.

Sincerely,

Patrick McManusRemedial Project ManagerSoutheast PA Section

Enclosures

cc: Martin Kotsch, 3HW43Jim Clark, 3PM73Barbara Rudnick, 3HW13Dawn loven, 3HW13Bob Davis, 3HW13

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY•REGION III

841 Chestnut BuildingPhiladelphia, Pennsylvania 19107̂ 431

Mr. Scott McEwen •CH2M Hili ' . . . . . : •P.O. Box 4400 .Reston, VA 22090-1483 :

Re: North Penn Area 12 Superfund Site :RI/FS Work Plan ' .iBiological Technical Assistance Group Comments !

Dear Scott: '

As a follow up to my January 12, 1994 letter, please findattached the written comments from the biological technicalassistant group ("BTAG"). , The attached memo documents all thecomments made by the BTAG on the North Penn Area 12 york plan.Please consider these comments with the comments included in theJanuary 12 letter in amending the work plan. '

iIf you should have any questions concerning this matter,

please call me at (215) 597-8257. ; |

Sincerely,

Patrick McManusremedial Project Manciger

Enclosure

AROOOW5

UNITED STATES ENVIRONMENTAL PROTECTION AGENCYREGION III

841 Chestnut BuildingPhiladelphia, Pennsylvania 19107

SUBJECT: North Penn Area 12: RI/FS Work Plan DATE: 1-11-94(Revised)

FROM: Robert S. Davis, Coordinator (3HW13)Biological Technical Assistance Group

TO: Pat McManus, RPM (3HW62)

The BTAG has reviewed the subject document and offers the followingcomments for your use, on behalf of NOAA, FWS and EPA BTAG members.

We support the proposed phased approach of studying the .area withemphasis on determining first if terrestrial and aquatic environ-mental receptors are exposed to site contaminants. The order ofthe tasks appears logical and will, with adoption of BTAG's speci-fic comments, provide information for determining need and scope ofa detailed ecological characterization and assessment. Specificcomments on the proposed tasks are as follows:

/

• Subtask FI.FW. Surface Water and Sediment Sampling. Analysisof sediment samples "should include grain size along with theattached list of other parameters. It is noted that sampling isscheduled during storm events, but we prefer sampling be carriedout 2-3 days after a storm event. We do not believe that samplingduring a storm event can be representative of normal site condi-tions.

The work plan has stated there are four sampling locations. Duringthe January 5, 1994 BTAG meeting, you noted that more than foursamples could be taken if additional areas (e.g., 'seeps) poten-tially affected by site contaminants are identified during fieldverification of sample locations. BTAG members would be glad tohelp where they can in extablishing appropriate sampling locations.

• Subtask FI.FB. Preliminary Wetlands Assessment. The prelimi-nary wetland assessment should include fauna in addition to thevegetation and soil of the wetland identification task. This taskshould be tied to our comment above referring to additionalsampling that may be needed. For example, any seep areas identi-fied during this assessment task should be considered for samplingin addition to the surface sampling locations mentioned above.

• Subtask FI.P2. Water-Level Trend Monitoring and Pump Test.We are concerned that a pump and treat action often has aninfluence upon wetland areas (e.g., dewatering). Therefore, we

ARQOO<436

suggest this task include 'an effort to establish if there is arelationship between pumping of ground water (and impacts to thewetlands identified in the other tasks. ! j

• Task AR. Assessment of Risk. The basis for .th£ site's eco-logical risk assessment (ERA) should consider more thjan merely theresults/observations made during one day of surface water and sedi-ment sampling and three days of wetland assessment| Additionaltasks include 1) the potential for ground water to ponvey eithercurrent or past site contaminants to surface media; 2) the poten-tial for surface soil to harbor site contaminants jat levels ofconcern to environmental receptors; and 3) the potential that asite remedy, such as ground water pump and treat, mky impact anyhabitat (e.g., dewater wetlands). To fully address! these consi-derations the ecological risk assessment should proceed in a phasedapproach. l

; I

Further reason for conducting a phased ERA at this|site is thatpast field ecological studies done by a prior contractor appearedto concentrate on only "important" environmental jreceptors or"sensitive" areas. As neither "important" and "sensitive" aredefined, BTAG assumes from past experience that these terms referto threatened/endangered species and wetlands,;respectively. Suchemphasis is not considered an adequate scope for an E^A, especiallyin the initial screening phase for a RI. !

• \ • ij iWe recommend this assessment task, in keeping with the phasedapproached described in the work plan, be modifiedito provide athorough initial ecological characterization. An initial char-acterization should include a physical description; and detailedmaps of the site and surroundings. Terrestrial vegetative com-munities, surf ace water bodies, and wetlands on the site and in thevicinity should be discussed in the text and depicted, on the maps.Information regarding animal/bird species expected t!o inhabit thevarious vegetative communities on or near the site should be ob-tained (e.g., from state fish and game agencies or :other naturalresource agencies) as well as from any observations'. Biologicalsurveys are not expected in the initial RI study phase, especiallyif site contaminants are not known or expected to impact surfaceterrestrial and aquatic habitats. : [

This initial characterization should also 'include contacting thethe U.S. Fish and Wildlife Service in accordance with Section 7 ofthe Endangered Species Act of 1973 (87 Stat. 884, as amended; 16U.S.C. 1531 et seq.) for information on the presence of federallylisted or proposed endangered and threatened specifes within thearea potentially affected by site contamination1 or remedialactions. For sites in Pennsylvania write to: j• ti

Mr. Charles KulpU.S. Fish and Wildlife ServiceSuite 322, 315 South Alien'St.State College, PA 16801

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Thanks for the opportunity to comment, and if you have anyquestions contact Bob Davis on X3155.

AR0001438

UNITED STATES ENVIRONMENTAL PROTECTION AGENCYREGION III

841 Chestnut BuildingPhiladelphia, Pennsylvania 19107

SUBJECT: North Penn Area 12 \ DffTE: 1-3-94RI/FS Work Plan j(Revised November 1993) I

IFROM: Barbara Rudnick, Geologist

Technical Support Section (3HW13)

TO: Pat McManus, RPMSE PA Section, 3HW21 '

I have reviewed the above reference document arid have preparedthe following comments for your consideration. As th;e draft plandated June 1992 was reviewed for hydrogeologic :issues; by JayNewbaker and comments submitted July 22, 1992, I checked therevised report to see if the comments were addressed.; In readingthe plan, a few additional concerns seemed apparent and have beenincluded for your perusal. : j

All comments prepared by Jay were incorporated in the revisedplan with the exception of that f or, Subtask FS; Soil '.Investigation. Jay suggested that a soil gas survey at the formerNike Battery Control Area would reduce the number of ;soil samplesnecessary to define conditions at the site, and thereby reducecosts. Secondly, Jay recommended that past site operations andaerial photographs should be reviewed to aid in targeting areasof high industarial use and potential contamination. |As thesesuggestions were not incorporated, and seem relevant/ they couldbe mentioned again. !

. ' iA few additional points are: I

i - .1. The work proposed to analyze flow dynamics is somewhat

limited, but includes water-level monitoring and an aquiferpumping test (Subtask FI.P2; Water-Level Trend Monitoririgand Pumping Test, p. 4-41). Some things could be done toenhance the data collected during execution of these tasks.

The water-level trend monitoring was described by theprevious consultant (ERM) in section 3.1.3.6 Extended WaterLevel Test, p.3-10. It was proposed that monitdring beconducted at three locations over an eight-day period inorder to determine water-level trends and sources offluctuations. ERM proposed installation of recorders at thenested wells west of the site (MW-9, 10, 11, 12), MW-5 (westof the Rehab well), and T-3. . !

AROOCH39

I do not know if they will be able to correlate water-levelfluctuations with pumping at production wells with thesedata alone. First, it would be essential to get the pumpingschedule of the production wells (including on-site), withwater-level record, in order, to separate effects of pumpingactivities. It would be of help to be able to control thepumping schedule of the production wells, if co-operationcould be solicited. The production wells may be equippedwith continuous recorders, or the wells could be madeaccessible for manual measurement.

Information on the construction of the production wellswould be of great advantage. If the wells are permittedunder the Delaware River Basin Commission (DRBC),construction data as well as pumping test and localgroundwater level monitoring data may be available. Thiscould be investigated (or maybe it has already).

It would also seem wise to monitor wells at more than threelocations. Monitoring the proposed wells, in addition topoints closer to the production wells, could provide moresubstantial data. It is possible that the wells west of thesite will not show impact during an intermittent pumpingschedule, and no information would have been gleaned inregard to the direction of impact. I think the exercisecould be made very worthwhile, if a little more resourcewere put into it.

It was also noted that the title of the subtask in the CH2MHILL (p. 4-41), differs from that listed in the TechnicalApproach summary, p. 4-1 (reported in the list as SubtaskFI.P1; Monthly and Extended Water Level Monitoring andPumping Test).

2. Subtask FI.P2; Water-Level Trend Monitoring and Pumping Testincludes an aquifer pumping test to "determine ifgroundwater pumping is a viable remedial alternative for VOCrecovery". It is stated that the well used will be selected"on the basis of existing well data and pumping duringdevelopment of the seven new monitoring wells". Pumping todevelop the well, in addition to estimating yield as theysuggest, is important.

They could pick up some easy additional information abouthydraulic interconnection between wells by measuring waterlevel in the monitoring wells (manual or continuousrecorder) during pumping. This is "quick and dirty", not byany means a substitute for a pump test, but may yieldinformation of use in selecting a well for the pumping test(for instance, a well showing hydraulic interconnection tothe known contaminated wells) and to help define some of theflow dynamics. -

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It is uncertain if the extent of the plume can be defined bythe monitoring and existing residential and productionwells. Of particular concern is the vertical extent ofcontamination. Results of the packer test performed on T-6were not included in the reports. Additionally,1 MW-10, a"deep" well is 154 feet, and nested with a shallow well of •124 feet. As I have not seen the geologic and drilling log,nor well construction diagram, and do not know the depth orcontrol of the water zone, it is uncertain that the waterzones are not interconnected. I

MW-12 (to be constructed to be a depth of 211 feet) seemedto be of low yield. If its hydraulic interconnection is ofa very limited extent, it will be of limited use1 as amonitoring well. '

Additional, deep wells may be required at some p|oint in theinvestigation. I

i -'• • \Subtask FI.FR; Residential Well Sampling reviews results ofprevious sampling of domestic wells and proposes! additionallocations. It is unfortunate' that they did not include a mapindicating contamination levels for previous sampling eventsfor the residential wells. This would have been helpfulwith consideration to confirming additional samplinglocations, seeing correlation between contaminantconcentrations, and any changes over time. Some! informationcan be gleaned from Table 4-3 and Figure 4-2. It isindicated in Table 4-4 that 10 locations are yeti to beidentified.

In reviewing the data given, it may be appropriate for themto consider additional locations along strike (eg. Block17-6, if well location on the property is appropriate),further down dip (in Block 15 and 16), control jto thesoutheast (eg. Block 17 - 39, 40, 51), and to investigatechanges in concentrations over time by re-sampling some ofthe previously sampled wells. They may have thesse, orbetter ideas, in mind. j •

iCH2M HILL proposes to evacuate wells with a centrifugal orsubmersible pump, and collect samples with dedicated bailers(Subtask FI.FQ; Groundwater Sampling, p. 4-35). i Wellpurging and sampling has conventionally been don'e' in thismanner. Recent studies have indicated thcit low-jflow purging(pumping at very low rate, maintaining constant iwater levelin the well, and pumping from a section within tjhe screenedinterval), and in-line sampling, is very effective inacquiring representative samples (especially foif metals, butapplicable to VOCs). Region III is advising considerationof this method for current projects. Bailers are' beingdiscouraged for sampling in favor of in-line sampling. Ifbailers are used, care must be taken to allow slow release

'of sample from the check valve, and a double valve bailerused. In well evacuation, pumping the well dry is stronglydiscouraged.

cc: Eric JohnsonDawn IovenBob Davis

ARQOOH2

UNITED STATES ENVIRONMENTAL PROTECTION AGENCYREGION III

841 Chestnut BuildingPhiladelphia, Pennsylvania 19107

SUBJECT: Draft Work Plan DATE: 1-4-94North Penn Area 12 !

FROM: Dawn A. Ioven, Senior ToxicolegistTechnical Support Section (3HW13)

TO: Pat McManus, RPM ;Southeastern PA Section (3HW21) j

The draft Work Plan (WP) for the-North Penn Area 12 site wasreviewed for comprehensiveness and technical accuracy.Particular attention was focused on those aspects of; the reportrelated to toxicological concerns and human health issues. Inthis regard, the following comments are offered: |

i

On page 3-5 of the report, the exposure pathways expected to beevaluated in the Baseline Risk Assessment (BLRA) are presented.However, it appears that contaminated ground water wMinadvertently omitted as a pathway of concern. Please revise theWP to include ground water as an exposure pathway that will beassessed in the BLRA. j

According to page 3-5, Toxicological Profiles are "important forthe contaminants of concern to which no quantitative! RfDs orslope factors have been assigned". Please note, however, thatToxicological Profiles, although especially important forchemicals lacking toxicity criteria, should be provided in theBLRA for all contaminants of concern at the site.

iIn Table 3-4, an example of exposure parameters for Assessingdermal contact with chemicals in soil is presented. : It isimplied in this table that, in the absence of chemical-specificabsorption factors, 100 percent absorption will be assumed. Suchan assumption for contaminants bound to soil is grosslyconservative, however. If chemical-specific dermal absorptionfactors (for soil) are unavailable in the literature1, thefollowing default values should be used: organic compounds - 1percent; inorganics - 0.1 percent. |

On page 4-21 of the report, details of the proposed soilinvestigation are provided. It is not clear from this narrative,however, whether surface soil samples will be collected« Pleaseclarify the report, as necessary.

AROOoUci

-2-

. ̂ The proposed procedure for ground water sampling is presented on(̂ page 4-35 of the report. According to this discussion, for

inorganic analyses, both filtered and unfiltered monitoring wellsamples will be collected, as dictated by Regional policy.However, experts currently believe that the use of low-flow pumpsduring sample extraction may provide a'more representativepicture of ground water conditions, thus eliminating the need forfiltered and unfiltered sample collection and analyses. In thisregard, the hydrogeologist assigned to the site should beconsulted for further information.

,,• Proposed surface water and sediment sampling locations are(- presented in Figure 4-6. It is unclear, however, which of the

proposed samples is being collected from an upgradient location.Please provide this information in the report.

According to page 4-45, "up to 25 percent of the PRP's data" willbe validated to CLP standards. Please note, however, that forthe purpose of the BLRA, the minimum requirement for validationis Data Quality Objective (DQO) - Level 3. Therefore, unless theremaining PRP data are validated at DQO - Level 3 or greater,these data will not be useable for the BLRA.

Beginning on page 4-48 of the report, a discussion of theprocedure for conducting the BLRA is presented. In addition tothe guidance cited in this discussion, when preparing the BLRA,Region III Technical Guidance for selecting contaminants ofconcern, choosing monitoring well results, handling non-detects,etc., should be followed.

cc: Bob Davis (3HW13)Barbara Rudnick (3HW13)

'- • 1'UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III j841 Chestnut Building j

Philadelphia, Pennsylvania 19107

SUBJECT: North Penn Area 12: RI/FS Work Plan DATE: 1-11-94(Revised) "

FROM: Robert S. Davisl/, Coordinator (3HW13)Biological Technical Assistance Group

TO: Pat McManus, RPM (3HW62)

The BTAG has reviewed the subject document and offers the followingcomments for your use, on behalf of NOAA, FWS and EPA BTAG members.

\We support the proposed phased approach of studying the area withemphasis on determining first if terrestrial and aquatic environ-mental receptors are exposed to site contaminants. LThe order ofthe tasks appears logical and will, With adoption of BTAG's speci-fic comments, provide information for determining need, and scope ofa detailed ecological characterization and assessment. Specificcomments on the proposed tasks are as follows: |

.• Subtask FI.FW. Surface Water and Sediment Samplihq. Analysisof sediment samples should include grain sizealong with theattached list of other parameters. It is noted that sampling isscheduled during storm events, but we prefer sampling be carriedout 2-3 days after a storm event. We do not believe jthat samplingduring a storm event can be representative of normal site condi-tions. |

The work plan has stated there are four sampling locations. Duringthe January 5, 1994 BTAG meeting, you noted that more than foursamples could be taken if additional areas (e.g., seeps) poten-tially affected by site contaminants are identified: during fieldverification of sample locations. BTAG members would be glad tohelp where they can in extablishing appropriate sampling locations.

• Subtask FI.FB. Preliminary Wetlands Assessment. The prelimi-nary wetland assessment should include fauna in addition to thevegetation and soil of the wetland identification task. This taskshould be tied to our comment above referring to additionalsampling that may be needed. For example, any seep 'areas identi-fied during this assessment task should be considered for samplingin addition to the surface sampling locations mentioned above.

1 i• Subtask FI.P2. Water-Level Trend Monitoring and Pump Test.We are concerned that a pump and treat action often has aninfluence upon wetland areas (e.g., .dewatering). Therefore, we

suggest this task include an effort to establish if there is arelationship between pumping of ground water and impacts to thewetlands identified in the other tasks.

• Task AR. Assessment of Risk. The basis for the site's eco-logical risk assessment (ERA) should consider more than merely theresults/observations made during one day of surface water and sedi-ment sampling and three days of wetland assessment. Additionaltasks include 1) the potential for ground water to convey eithercurrent or past site contaminants to surface media; 2) the poten-tial for surface soil to harbor site contaminants at levels ofconcern to environmental receptors; and 3) the potential that asite remedy, such as ground water pump and treat, may impact anyhabitat (e.g., dewater wetlands). To fully address these consi-derations the ecological risk assessment should proceed in a phasedapproach.

Further reason for conducting a phased ERA at this site is thatpast field ecological studies done by a prior contractor appearedto concentrate on only "important" environmental receptors or"sensitive" areas. As neither "important" and "sensitive" aredefined, BTAG assumes from past experience that these terms referto threatened/endangered species and wetlands, respectively. Suchemphasis is not considered an adequate scope for an ERA, especiallyin the initial screening phase for a RI.

We recommend this assessment task, in keeping with the phasedapproached described In the work plan, be modified to provide athorough initial ecological characterization̂ . An initial char-acterization should include a physical description and detailedmaps of the site and surroundings. Terrestrial vegetative com-munities, surface water bodies, and wetlands on the site and in thevicinity should be disdussed in the text and depicted on the maps.Information regarding animal/bird species expected to inhabit thevarious vegetative communities on or near the site should be ob-tained (e.g., from state fish and game agencies or other naturalresource agencies) as well as from any observations. Biologicalsurveys are not expected in the initial RI study phase, especiallyif site contaminants are not known or expected to impact surfaceterrestrial and aquatic habitats.

This initial characterization should also include contacting thethe U.S. Fish and Wildlife Service in accordance with Section 7 ofthe Endangered Species Act of 1973 (87 Stat. 884, as amended; 16U.S.C. 1531 et seq.) for information on the presence of federallylisted or proposed endangered and threatened species within thearea potentially affected by site contamination or remedialactions. For sites in Pennsylvania write to:

Mr. Charles KulpU.S. Fish and Wildlife Service

\ Suite 322, 315 South Alien St.State College, PA 16801

Thanks for the opportunity to comment, and. if you have anyquestions contact Bob Davis on X3155. I

SURFACE WATER AMD SEDIMENT CHARACTERIZATION

CHEMICAL AMD PHYSICAL PARAMETERS:

The following parameters are considered to be the minimumrequired to characterize a site. In some cases, other parametersmay be specified where endangerment is suspected and additionalwork may shed light on the situation.

Surface water:

Field Parameters

TemperatureDissolved oxygen (DO)PHConductivitySalinity (for marine and estuarine systems only)Flow

Laboratory parameters

Total suspended solids (TSS)AlkalinityHardnessOptional (BOD, COD, total dissolved solids,

non-settleable solids)

Sediment:

Field Parameters

TemperatureEh (see EPA 9045 for methods)PHConductivityColor (Munsell)

Laboratory Parameters

Total organic carbon (see EPA 415.13, combustionmethodology; report as % organic carbon)

Grain size (ASTM hydrometer method or Emery tube)Moisture (report as %) (Routine Analytical Services)Solids (report as %) ( » " " )

COMMONWEALTH OF PENNSYLVANIADEPARTMENT OF ENVIRONMENTAL RESOURCES

LEE PARKSUITE 6010

555 NORTH LANECONSHOHOCKEN, PA 19428

December 21, 1993

Patrick McManusRemedial Proj ect ManagerUS EPA841 Chestnut BuildingPhiladelphia, PA 19107-44311

Re: North Penn Area 12 Superfund Site,Worcester, PAPA DER Comments on Draft Final Work Plan

Dear Patrick: |

I have read the North Penn Area 12 RI/FS submitted to youby CH2MHill and find it to be a clearly written an<jl thoroughdocument: However, I do have a few comments which are listedbelow. j

1. Page 3-3, Table 3-1 ' . ,The Extended Water Level Test is shown as Subtask FI.P2.

This is probably a typographical error, because this task islisted as Subtask FI.P1 in Section 4. iii

2. Page 3-13, Table 3-6 :. - | .Please include the PA DER Ground Water Protection

Strategy which specifies that ground water must be| cleaned upto background (as defined under 25 PA Code Chapter; 264,Sections 97 and lO'O) , or as close to background asj feasible,without causing greater environmental harm. |ii

3. Page 3-13, Table 3-6 . j . ' .

An Equal Opportunity/Affirmative Action Employer - - j Recycled Paper ,5

Include DER soil cleanup standards that apply to thegroundwater protection strategy. These standards are levelsof contaminants, which, if left in the soil at the end of thecleanup activities, will not have.a harmful impact ongroundwater above MCLs, or background, whichever is morestringent, if they did migrate to groundwater. The Summersmodel is commonly used for the purpose of modeling soilcontaminant concentration levels protecive of groundwater.This model could be included in the FS.

4. Page 4-27, Subtask FI.FPIf the caliper, sonic, and natural gamma ray logs are not

found, will these tests be redone on wells six through 11?

Yours truly,

Barbara BloomfielcHydrogeologistEnvironmental Cleanup Program, HSCA Section

copies: T. SheehanG. DanyliwR. Day-LewisB. Beitler

ftRO-QOl*50

COMMONWEALTH OF PENNSYLVANIADEPARTMENT OF ENVIRONMENTAL RESOURCES

LEE PARK !SUITE 6010 1

555 NORTH LANECONSHOHOCKEN, PA 19428

December 22, 1993

Patrick McManusRemedial Project ManagerUS EPA841 Chestnut BuildingPhiladelphia, PA 19107-44311

Re: North Penn Area 12 Superfund Site,Worcester, PAPA DER Comments on Draft Final Work Plan

Dear Patrick:I

I am sending you this letter in order to correct one ofthe comments in the letter which I sent you yesterdayconcerning North Penn Area 12. The revision concerns commentthree which is changed as follows: !

Page 3-13, Table 3-6 !Include DER soil cleanup standards that apply,to the

groundwater protection strategy. These standards!are levelsof contaminants, which, if left in the soil at th^ end of thecleanup activities, will not have a harmful impact on groundwater. DER uses the CREST Model as the basis of soil cleanupstandards.

Yours truly,

Jarbara BloomfieldHydrogeologistEnvironmental Cleanup Program, HSCA Section

copies: T. SheehanG. DanyliwR. Day-LewisB. Beitler

ARDUOUS!An Equal Opportunity/Affirmative Action Employer Recycled Paper