Record of Decision Amendment to Change Groundwater …change the remedy at the Conrail Site fundamentally altered the basic features of the selected remedy, and this necessitated the

Record of Decision Amendment to Change Groundwater Remedy

Elkhart, Indiana/ ' • , " • * " "

Introduction I £ *- ^

Reasons for a Change in Remedy

Norfolk-Southern (formerly Conrail) and American Premier Underwriters (formerly PennCentral) are currently performing the remedial actions for the Conrail Superfund Site inElkhart, Indiana (the Conrail Site or the Site). The United States EnvironmentalProtection Agency (USEPA) is the lead enforcement agency on this site with theIndiana Department of Environmental Management (IDEM) as the support agency foroversight of the remedial action at the Site under the authority of the ComprehensiveEnvironmental Response, Compensation and Liability Act (CERCLA), as amended, 42U.S.C. § 9601, et seq. In September 1994, USEPA issued a Record of Decision (1994ROD) which outlined the remedy selection process and selected the cleanup actions forthe contaminated media at the site, including groundwater. The State concurred withthe selected remedy. During Remedial Design (RD), information has come to lightwhich necessitates modifications to aspects of the portion of the remedy related to theground water cleanup. This document provides the background information as to whythe modifications are necessary and outlines what modifications to the selected remedyare being adopted. On February 3, 2000, the Settling Defendants submitted a revised"Petition for a Technical Impracticability (Tl) Waiver and Request for RemedyReconsideration" (the Petition) to USEPA asking that the Agency amend the 1994 RODto change the ground water remedy. In this document, the Settling Defendants broughtto USEPA's attention largely new information that substantially supports the need tosignificantly alter the remedy. This information is summarized below:

1) Using current technology, it is not technically feasible to clean up the two densenon-aqueous phase liquid (DNAPL) source areas on the rail yard property withina reasonable time frame; thus, the Settling Defendants are requesting a TlWaiver for these two areas.

2) Given the above information, the source areas should be hydraulically contained.Modeling submitted by the Settling Defendants indicates that, with the exceptionof the Drag Strip area, once the source areas are contained, pumping andtreating ground water will not result in a significant decrease in the amount oftime it will take for contaminant levels to reach the Maximum Contaminant Levels(MCLs); thus, the Settling Defendants recommended that the dissolved portionsof the plumes be cleaned up through natural gradient flushing. The Drag Stripground water source area would need to be remediated since the presence ofthis contamination would significantly extend the amount of time needed for thedissolved portions of the County Road 1 plume to flush naturally.

USEPA agrees with the above conclusions and is making these changes to the 1994

ground water remedy through this ROD Amendment. In accordance with the RemedialDesign/Remedial Action Consent Decree for the Conrail Site, execution of this RODAmendment constitutes the Agency's decision with respect to the Petition.

Procedure for Changing the Remedy

Under Section 117(c) of the Comprehensive Environmental Response, Compensationand Liability Act (CERCLA), 42 U.S.C. § 9617 and Section 300.435(c)(2)(ii) of theNational Oil and Hazardous Substances Contingency Plan (NCP), if USEPA proposesto fundamentally alter the basic features of the selected remedy with respect to scope,performance, or cost, the Agency shall publish the proposed amendment, receivecomments, and provide an opportunity for a public meeting. The decision by USEPA tochange the remedy at the Conrail Site fundamentally altered the basic features of theselected remedy, and this necessitated the issuance of a new proposed plan and anamended ROD.

Accordingly, a proposed plan was issued in May 2000, and the public was invited tocomment on the alternative remediation methods proposed in the proposed plan . A 30day public comment period was initiated and a public meeting to discuss the proposedchange in the remedy was held on May 11, 2000 at 7:00 pm at the Harley HolbenElementary School in Elkhart, Indiana.

This proposed plan is part of an administrative record which is available for publicinspection at the Elkhart Public Library in Elkhart, Indiana. This amended ROD also willbecome part of the administrative record for the site. The administrative record mayalso be reviewed at USEPA Region 5, 77 West Jackson Boulevard, Chicago, Illinois.The most recent update to the administrative record comprises Appendix A to this RODAmendment.

After reviewing the current status of the Site and comparing remedial alternatives,USEPA believed that the request made by the Settling Defendants to amend theremedy for the contaminated ground water at the Conrail Site had merit and should beevaluated. Consequently, USEPA proposed to amend the ground water portion of the1994 ROD to change the previously selected remedy. After reviewing the publiccomments, USEPA has determined to change the selected remedy for ground waterfrom pump-and-treat to MCLs to hydraulic containment of DNAPLs on the rail yard andnatural gradient flushing of the dissolved portion of the ground water contaminationplumes, with cleanup of the Drag Strip source areas. This amended remedy willinclude the following major components: hydraulic containment of DNAPL sourceareas; natural gradient flushing; Drag Strip source area remediation; ground watermonitoring, and contingency remedy.

I. Site Location and Description

The rail yard began operations in 1956 as part of the New York Central Railroad, and

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continued as a subsidiary of the Penn Central Transportation Company (now known asAmerican Premier Underwriters) until 1976. From 1962 to 1968, numerous citizencomplaints regarding oil discharges from the rail yard to the St. Joseph River via theCrawford Ditch were filed with state and local authorities.

In 1976, operations at the rail yard were transferred to the Consolidated Rail YardCorporation (Conrail). From 1976 to the present, spills and releases of oil, diesel fuel,hydrochloric acid, caustic soda, and various petroleum-related substances haveoccurred there. Reports also indicate that a track-cleaning substance (the chemicalcomposition of which is unknown) and engine degreasers were used and disposed of atthe rail yard.

The Conrail Site is partially located within the southwestern city limits of Elkhart,Indiana. The remainder of the Site extends into St. Joseph County to the west. TheSite encompasses the 675-acre Elkhart Yard of Conrail (now operated by NorfolkSouthern), and the area to the north to the St. Joseph River, most of which isresidential. Areas of ground water contamination extend from within the Conrail RailYard in two directions, north and northwest, into residential areas, designated as theCounty Road 1 area, the LaRue Street area, the Vistula Avenue area, and the CharlesAvenue area (see Figure 1). Contaminants detected in samples collected from privatewells in these areas include carbon tetrachloride (CCI4), trichloroethylene (TCE), andother volatile organic compounds (VOCs).

Based upon sampling performed by EPA representatives in 1986, bottled water wasprovided to residents whose wells were affected by the contamination. Either carbonfilters or water main connections were later installed in residences to ensure safedrinking water.

II. Site History and Enforcement Activities

EPA also conducted an inspection of the Conrail Site in 1986. The results of thatinspection revealed TCE concentrations as high as 5850 parts per billion (ppb) andCCI4 concentrations as high as 117 ppb in soil samples. Based on these results, thelocation of TCE- and CCI4-contaminated private wells down gradient from the rail yard,and the history of waste handling practices at the rail yard, the Conrail Site was placedon a roster of sites proposed for inclusion on the National Priorities List (NPL) in June1988.

The first phase of the Remedial Investigation (Rl) was completed in January 1990, anddetailed in the April 1990 Preliminary Evaluation Report, as well as being summarizedin a June 1990 fact sheet. During the Rl, various investigations were undertaken,including a soil gas survey as well as soil and ground water sampling.

Further investigations were conducted at the Conrail Site, and the final RemedialInvestigation report summarizing the results of these investigations was completed in April1994.

Collectively, the results from the various investigations indicated that:

- Based on soil sampling data, there were two well-defined source areas on the Conrailfacility, a CCI4 source area in the eastern section of the classification yard and a TCEsource area in the western section of the classification yard, approximately 1900 feet westof the eastern straight-a-way between tracks 65 and 66;

- A third potential source area with lower levels of contamination was identified in theeastern portion of the Conrail rail yard; and

- There were two identified ground water contaminant plumes coming from the Conrailfacility, the County Road 1 plume and the LaRue Street plume. Refer to Figure 2 for thelocations and approximate extent of these contaminant plumes.

SCOPE OF INTERIM REMEDIAL ACTION

The Record of Decision (ROD) for interim ground water remedial action at the Conrail Sitewas signed in June 1991. On July 7, 1992, ERA issued a Unilateral Administrative Orderfor Remedial Design and Remedial Action (Order), which required Conrail and AmericanPremier Underwriters (APU) to perform the following remedial activities (only Conrailcomplied with this Order):

• Approximately 460 residences were hooked up to the Elkhart municipal watersupply between August 1994 and February 1996. Residential wells wereabandoned at all residences that received a hookup. Approximately 25 residentsrefused the hookup;

• A quarterly ground water monitoring program was established; and

• The ground water extraction, treatment, and discharge system outlined in the RODwas not constructed since the final ROD included a provision for a more extensiveground water pump-and-treat system.

SCOPE OF FINAL REMEDIAL ACTION

The ROD for the final Remedial Action at the Conrail Site was signed on September 9,1994. In May 1995, EPA issued a second UAO to Conrail and APU to connect an

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additional 675 residences to the alternate water supply. This work was performed byConrail from August 1995 to December 1996. Approximately 35 residents refused thebackup In Nnvejnhej; 1997., EPA entered into a Consent Decree with Conrail and APU.Under the terms of the Consent Decree, Conrail and APU were to perform the followingwork:

• Further sampling of a small area of the rail yard for VOCs, and if needed, cleanupof this soil using soil vapor extraction;

• Investigations of the Dense Non-Aqueous Phase Liquids (DNAPLs) source areason the rail yard and the Osceola Drag Strip;

• Sampling, and if necessary, cleanup of VOC vapors in residential basements; and

• Performance of an Ecological Study on the St. Joseph River to determine if rail yardcontamination was having an adverse impact on aquatic life in the river.

The rail yard soil sampling indicated that there were no samples that exceeded applicablecleanup levels in the area that was previously found to have a high concentration of TCE.Thus, no cleanup was necessary for rail yard soils.

The source investigations indicated that a source of CCI4 contamination exists in thesouthwestern portion of the Osceola Drag Strip property. Additionally, the sourceinvestigations supported the conclusions of previous EPA studies with respect to DNAPLson the rail yard. A CCI4 DNAPL area exists in the track 69 area of the classification yard,and a likely TCE DNAPL area exists in the track 65/66 area.

Initial vapor sampling was conducted in 16 homes in site areas which were more likely tohave vapor problems (i.e., high water table, highly contaminated shallow ground water).After two rounds of sampling, an area near the Osceola Drag Strip was identified as havingdetectable levels of CCI4 in residential homes, primarily in the basements. Thoroughtesting of the Ash Road-Lehman Street-Vistula Avenue area indicated that six homesexceeded EPA's level of concern for CCI4 for the Conrail Site, and 5 more homes haddetectable levels of CCI4 but below the level of concern. A plan was generated by Dames& Moore, Conrail's and APU's contractor, to remediate the six homes and continue tomonitor the five additional homes. EPA approved this plan, and all six homes have beenprovided with soil gas depressurization units. Testing of the units that have been installedindicates that CCI4 has been effectively reduced to non-detectable levels or to aconcentration that is below the level of concern for CCI4.

III. Community Relations History

The proposed ROD Amendment was issued to the public on May 11, 2000. This begana 30 day public comment period on the proposed amendments. A public meeting to

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discuss and receive comments on the proposed ROD amendment was held at theHarley Holben Elementary School in Elkhart on May 11, 2000. The comment periodended on June 12, 2000. See Section 111 of the 1994 ROD for the community relationshistory prior to this ROD Amendment.

IV. Scope and Role of Operable Unit

USEPA has organized this project into two operable units- the interim remedial actionand the final remedial action. See the discussion above for details regarding thecomponents of the remedies for the two operable units.

V. Site Characteristics

See 1994 ROD for complete description. Additional post-ROD information regarding sitecharacteristics is summarized in the February 2000 Petition.

VI. Site Risks

See 1994 ROD for complete description. In 1998, an ecological study was performed inthe St. Joseph River. The area where the ground water is discharging to the river waslocated, and biota samples were collected upstream, downstream, and within thedischarge area. The conclusions of the ecological study were that the site contaminantsentering the river did not cause a noticeable impact on the biological communities in theriver.

VII. Remedial Action Objectives

For ground water contamination at the Conrail Site, the cleanup objectives are the MCLs forthe following compounds: trichloroethylene (TCE), carbon tetrachloride (CCI4), 1,1-dichloroethene, 1,2-dichloroethene, chloroform, tetrachloroethylene, and vinyl chloride.A Tl Waiver for the DNAPL source areas on the rail yard will serve to waive theseremedial action objectives within the area to which the Tl Waiver applies. Instead,hydraulic containment will be required for these DNAPL source areas.

VIII. Development of Remedial Action Alternatives

Four alternative cleanup methods were evaluated. Alternative 1 was the no furtheraction alternative, as required by the National Contingency Plan (NCP). Alternative 2consisted of hydraulic containment of the DNAPL areas, natural gradient flushing,remediation of the Drag Strip source area, ground water monitoring, and a contingencyremedy (if the containment and/or natural gradient flushing failed). Alternative 3 was

the same as Alternative 2, except that additional wells were to be installed in thedissolved portion of the ground water contaminant plumes to accelerate the cleanup ofthe plumes. Alternative 4 was the original ROD remedy, pumping and treating groundwater to the drinking water standards throughout the contaminant plumes. This sectiondescribes these alternative cleanup strategies. These alternatives are described ingreater detail in the Petition.

Alternative 1: No Further Action

The no further action alternative includes no remedial actions for ground waterremediation. Therefore, in compliance with the NCR, the no further action alternative isdeveloped and evaluated to serve as a baseline for comparison with other alternatives.Under the no further action alternative, no efforts would be made to mitigate the effectsof or control the migration of ground water contamination identified at the Conrail Site.

Estimated Cost: $0Estimated Design/Construction Time Frame: 0 Months (No O&M)

Alternative 2: Hydraulic Containment of DNAPL Source Areas; Natural GradientFlushing; Drag Strip Source Area Remediation; Ground Water Monitoring andContingency Remedy

This alternative includes a measure to contain the source areas (see Figure 3). A lineof extraction wells would be installed, as indicated on Figure 3, to hydraulically containthe DNAPL source areas. Contaminated ground water that is extracted would betreated using air strippers, with the treated water discharged to Crawford Ditch, subjectto a demonstration that such discharge will not have an adverse impact on CrawfordDitch and the St. Joseph River. Exhaust from the air strippers would be treated byvapor phase carbon adsorption prior to emission. Spent carbon would be disposed ofproperly.

The dissolved portion of the contaminant plumes would be allowed to flush naturally. Aground water monitoring program would be established to determine the effectivenessof the source containment and natural gradient flushing, as well as furthercharacterizing the contaminant plume emanating from the Track 69 area and someoff-rail yard areas where TCE levels may be increasing. A contingency remedy wouldbe developed to address failure of the hydraulic containment system to adequatelycontain the DNAPL sources and/or inadequate performance of natural gradientflushing.

The Drag Strip area would be further investigated and remediated. Investigationactivities could include geophysical investigations, such as magnetometer surveys orground penetrating radar, excavation of test pits, and/or further ground water

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monitoring. Remedial action at the Drag Strip area could include removal of soil and/ordrums, tanks, and containers and off-site disposal, soil vapor extraction, and/orhydraulic containment of the source area on the Drag Strip property.

Estimated Cost: $4,800,000Estimated Design/Construction Time Frame: 20-23 Months (O&M 30 Years)

Alternative 3: Hydraulic Containment of DNAPL Source Areas; Natural GradientFlushing Enhanced By Ground Water Extraction; Drag Strip Source AreaRemediation; Ground Water Monitoring and Contingency Remedy

This alternative includes all of the provisions of Alternative 2, with the addition of five off-railyard extraction wells to speed up the cleanup of the dissolved portion of the contaminantplumes.

Estimated Cost: $11,400,000Estimated Design/Construction Time Frame: 3-4 Years (O&M 30 Years\

Alternative 4: Groundwater Containment Beneath Facility, Groundwater RestorationOff-facility. (Selected Remedy in 1994 Record of Decision)

The groundwater extraction/treatment system for this alternative is similar to that forAlternative 2, differing in that extraction of groundwater down gradient from the facilitywould be expanded to actively restore to cleanup goals those portions of the aquiferoutside of the facility boundary. Alternative 4 includes a total of 8 extraction wells on andoff the facility, to contain the contamination at the facility and clean up the dissolvedportions of the contaminant plumes by emphasizing the cleanup of hots spots off the railyard facility.

Estimated Cost: $10,900,000Estimated Design/Construction Time Frame: 3-4 Years (O&M 30 Years)

IX. Evaluation of Alternatives

A. Evaluation Criteria

EPA's evaluation of remedial alternatives is based on the nine criteria set forth in theNational Contingency Plan (NCR), 40 CFR Part 300. These criteria are describedbelow.

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A remedial alternative is first judged in terms of the threshold criteria of protectinghuman health and the environment and complying with Applicable or Relevant andAppropriate Requirements (ARARs). If a proposed remedy meets these two criteria, itis then evaluated against the balancing and modifying criteria in order to arrive at a finalrecommended alternative.

Threshold Criteria

1. Overall protection of human health and the environment: USEPA determineswhether an alternative adequately protects human health and the environment fromunacceptable risks posed by hazardous substances, pollutants, or contaminantspresent at the site.

2. Compliance with ARARs: USEPA evaluates whether an alternative attainsapplicable or relevant and appropriate requirements under federal environmental lawsand state environmental or facility siting laws or provides grounds for invoking a waiver.

Balancing Criteria

3. Long-term effectiveness and permanence: USEPA considers the ability of analternative to maintain protection of human health and the environment over time, andthe reliability of such protection.

4. Reduction of contaminant toxicity. mobility, or volume through treatment: USEPAevaluates the degree to which an alternative uses treatment to address the principalthreats posed by the site.

5. Short-term effectiveness: USEPA considers the length of time needed toimplement an alternative and the risks the alternative poses to workers, residents, andthe environment during implementation.

6. Implementabilitv: USEPA considers the technical and administrative feasibility ofimplementing the alternative, such as relative availability of goods and services.

7. Cost: USEPA estimates an alternative's capital and O&M costs and calculatestoa ^esarrf.wytb. cost. piraaftHvato, c«sfc '&*frfc tetefc tsaft tfi -an ̂ ItemEtiwe over%ne :mterms of today's dollars.

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Modifying Criteria

8. State acceptance: USEPA considers any concerns the state has raised withrespect to the preferred alternative, other alternatives or with ARARs or ARAR waivers.

9. Community Acceptance: USEPA considers which components of the alternativesinterested persons in the community support, have reservations about, or oppose.

B. Application of the Evaluation Criteria to the FourCleanup Alternatives

1. Overall Protection of Human Health and the Environment

Alternatives 2 and 3 would provide adequate protection of human health and theenvironment. Since nearly all of the residents downgradient from the Site were hookedup to the Elkhart City water supply, the risk pathway of ingestion and inhalation of TCEand CCI4 vapors from drinking water has been almost fully addressed. In 1998, anecological study was performed in the St. Joseph River. The area where the groundwater is discharging to the river was located, and biota samples were collectedupstream, downstream, and within the discharge area. The conclusions of theecological study were that the site contaminants entering the river did not cause anoticeable impact on the biological communities in the river; thus, there are currentlyno unacceptable ecological impacts at the Site. Alternative 1 would not address thesource areas on the rail yard; thus, this contamination would continue to feed thecontaminant plumes for hundreds of years. Alternatives 2 and 3 would provideadequate containment of source areas on the rail yard, with Alternative 3 providing aquicker reduction of contaminant levels in the dissolved portions of the contaminantplumes. Alternative 4 would probably not provide adequate containment of the sourceareas, but would provide accelerated cleanup of the dissolved portion of thecontaminant plumes. Alternatives 2 and 3 would provide adequate protection ofresidents from CCI4 vapors in basements by cleaning up or containing the source areason the Drag Strip property; whereas, Alternatives 1 and 4 may not. Although fivehomes have been provided with vapor venting units to reduce CCL4 vapor levels intheir homes to acceptable levels, there are several residents in the potentially impactedarea which have not granted access for vapor testing. Since there are no provisions forcleaning up or containing the Drag Strip source areas included in Alternatives 1 and 4,these alternatives may not be as protective-of human health as Alternatives 2 and 3.

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2. Compliance with ARARs

Although all four alternatives would eventually meet the cleanup objectives (drinkingwater standards) for the chemicals of concern, the time required to achieve theseARARs would vary greatly. Alternatives 1 and 4 would probably take hundreds of yearsto achieve ARARs. Alternatives 2 and 3 would meet ARARs much more quickly, byproviding a Tl Waiver for and adequate containment of the rail yard source areas.Containment of DNAPL source areas is an essential element of accelerating the groundwater cleanup at the Conrail Site. Alternative 3, by including extraction wells in thedissolved portion oVfhe coritam'marit plumes, would achieve KRWRs more quic'rtiyfnanAlternative 2; however, modeling performed in the Petition indicated that this differencewould not be significant.

3. Long term effectiveness

Alternatives 1 and 4 would not be effective in the long-term since neither alternativecontains any provisions to address the Drag Strip source areas. This may result infuture exposure of residents to unacceptable vapor levels of CCI4 now and in thefuture. Alternatives 2 and 3 would provide long-term effectiveness since bothalternatives include provisions for cleaning up or containing the Drag Strip sourceareas. Alternatives 2 and 3 also include a contingency remedy in the event that theDNAPL ground water source areas on the rail yard are not adequately contained, and,for Alternative 2, that natural gradient flushing is not effective in reducing contaminantlevels in the dissolved portion of the contaminant plumes

4. Reduction of Toxicity, Mobility or Volume through Treatment

Alternatives 2 and 3 would provide a much greater level of reduction of mobility andvolume via containment of the DNAPL source areas on the rail yard and remediation orcontainment of the CCI4 source areas at the Drag Strip.

5. Short-term effectiveness

Alternative 1 (No Further Action) would provide the greatest level of short-termeffectiveness. Alternatives 3 and 4 may create more short-term impacts due to theinstallation and operation of extraction wells off the facility.

6. Implementability

All four alternatives are implementable. Alternatives 2, 3, and 4 all use effective,proven technologies.

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7. Cost

The total present worth costs for the alternatives is as follows: Alternative 1- $0;Alternative 2- $4,800,000; Alternative 3- $11,400,000; and Alternative 4- $10,900,000.Alternative 1 is the least costly, and Alternative 2 is significantly less costly thanAlternatives 3 and 4.

8. State Acceptance

State concurrence with the ROD Amendment is anticipated.

9. Community Acceptance

A few comments were received orally and in writing. These comments are addressedin the attached responsiveness summary. One change to the recommended alternativethat was made as a result of an oral comment was that rather than requiring thattreated ground water from the containment wells to be discharged to Crawford Ditch,subject to a demonstration that such discharge will not have an adverse impact on theSt. Joseph River, this component of the selected remedy now reads: "Treated water willbe discharged in a manner that will not adversely impact Crawford Ditch and the St.Joseph River."

Results of Comparison Using the Nine Criteria

Only Alternatives 2 and 3 meet the two basic, threshold criteria: they both wouldprovide for protection of human health and the environment; and they would meet stateand federal ARARs. Alternative 3 would meet ARARs for the dissolved portion of theplume more quickly than Alternative 2.

Considering the balancing criteria, Alternative 2 is superior in terms of short termeffectiveness and cost. Alternative 2 would cost $6.6 million less than Alternative 3.

The final step in the comparison is to consider the two modifying criteria: state andcommunity acceptance. Based on comments received from the Indiana Department ofEnvironmental Mangement and the public, USEPA has concluded that the state andcommunity support the change in the remedy. There is no preference indicated foreither Alternative 2 or 3, based on the public comments received by USEPA. USEPAhas therefore decided to change the ground water component of the remedy for the

ra/i 'Ste by cfrrrerrtifng'frie "i'Sfe^ f\C/D and setetfrng Wfternal'ive 2.

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X. The Selected Remedy

The ground water remedy for the Conrail Site is Alternative 2 - hydraulic containment ofDNAPL source areas; natural gradient flushing; drag strip source area remediation;ground water monitoring; and contingency remedy. The components of this remedy areas follows:

o Waiver of ground water ARARs in the area on the rail yard indicated on Figure 3;

o Installation of a line of extraction wells to hydraulically contain the DNAPL sourceareas on the rail yard;

o Air stripping of contaminated ground water that is extracted, with subsequentdischarge of treated water in a manner that will not adversely impact CrawfordDitch and the St. Joseph River;

o Treatment of exhaust from the air strippers with vapor phase carbon adsorptionprior to emission, with proper disposal of spent carbon generated by the process;

o Natural gradient flushing of the dissolved portion of the contaminant plumes;

o Establishment of a ground water monitoring program to determine theeffectiveness of the source containment and natural gradient flushing, as well asfurther characterization of the contaminant plume emanating from the Track 69area and some off-rail yard areas where TCE levels may be increasing;

o Development of a contingency remedy to address failure of the hydrauliccontainment system to adequately contain the DNAPL sources and/orinadequate performance of natural gradient flushing. The contingency remedyfor inadequate performance of natural gradient flushing would be to install andoperate additional extraction wells off the rail yard, as outlined in Alternative 3.For inadequate containment of DNAPLs, the contingency remedy would be toincrease the pumping rate of some or all of the extraction wells on the rail yardand/or installation and operation of additional extraction wells; and

o Further investigation and remediation of the Drag Strip area. Investigationactivities could include geophysical investigations, such as magnetometersurveys or ground-penetrating radar, excavation of test pits, and/or furtherground water monitoring. Remedial action at the Drag Strip area could includeremoval of soil and/or drums, tanks, and containers and off-site disposal, soilvapor extraction, and/or hydraulic containment of the source areas on the Drag

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Strip property.

XI. Statutory Findings

Section 121 of CERCLA requires the Agency to select remedies that:

1. Protect human health and the environment;

2. Comply with ARARs (or meet the conditions necessary to justify a waiver);

3. Are cost effective;

4. Utilize permanent solutions and alternative treatment technologies to the maximumextent practicable; and

5. Satisfy a preference for treatment as a principal element of the remedy.

The implementation of the amended remedy at the Conrail Site satisfies theserequirements as follows:

1. Protection of Human Health and the Environment

Hydraulic containment of DNAPL source areas on the rail yard, natural gradient flushingof the dissolved portion of the ground water contaminant plumes, and remediation ofthe Drag Strip source areas will be protective of human health and the environment.

2. Attainment of Applicable or Relevant and Appropriate Requirements

The selected remedy includes a provision for an ARARs waiver for the DNAPL sourceareas on the rail yard. The selected remedy will attain ARARs for the dissolvedportions of the ground water contaminant plumes. A complete list of ARARs is includedin the 1994 ROD for the Conrail Site; the ARARs for ground water, those associatedwith operation of extraction wells and discharge of treated water, and, if implemented atthe Drag Strip, those for removal of contaminated soils and/or containers apply to thisROD Amendment.

a. Chemical-specific ARARs

Maximum contaminant levels (MCLs) established pursuant to the Safe Drinking Water

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Act are ARARS for the Conrail Site. The cleanup levels established for groundwater inthis ROD for specific chemicals are consistent with these criteria. The area of the Sitewhere ARARs have been waived is shown on Figure 3. The specific ARARs that havebeen waived in this area of the Site are the MCLs for the following compounds:

carbon tetrachloride 5 ug/dl1,1 -dichloroethene 7 ug/dltrichloroethylene 5 ug/dl1,2-dichloroethene 70 ug/dltetrachloroethene 5 ug/dlchloroform 6 ug/dlvinyl chloride 2 ug/dl.

b. Action-specific ARARs

Air Emissions

The requirement for vapor phase carbon adsorption for the air discharge from the airstrippers meets or exceeds applicable federal and state law for the prevention ofsignificant deterioration of air quality.

Water Discharge

The treated water discharged from the air strippers will meet all applicable federal andstate requirements for such discharge.

3. Cost Effectiveness

Alternative 2 will cost $6.6 million less to implement than Alternative 3. Alternative 2also provides better short-term effectiveness than Alternative 3. Alternative 3 will meetARARs in less time than Alternative 2 (approximately 70 years versus approximately125 years).

Given the facts that all but three residences with levels of contaminants that exceed theapplicable drinking water standards are hooked up to the Elkhart City water supply(these three residences have been supplied with filters) and that the cost of Alternative2 is significantly less than that of Alternative 3, with only a one-third increase in theremediation time frame, ERA feels that Alternative 2 is the most cost effective remedythat meets the threshold criteria of overall protectiveness of public health and theenvironment and compliance with ARARs.

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4. Utilization of Permanent Solutions and Alternative Treatment Technologies orResource Recovery Technologies to the Maximum Extent Practicable

The preamble to the current version of the NCP discusses how to evaluate thepracticability of treatment:

Cost differences must also be considered in the context of all otherdifferences between alternatives to reach a conclusion as to whichalternative, all things considered, provides the most appropriate solutionsfor the site or site problem. It is this judgement that determines themaximum extent to which permanent solutions and treatment arepracticable for the site or site problem being addressed. (54 FR 8729)

In this case, the Tl Waiver was sought by the Potentially Responsible Parties due to thefact that it is impracticable to clean up DNAPLs at the Site in a reasonable time frame.Therefore, containment is the appropriate remedy for the DNAPL source areas.Alternative 2 includes the provision of treatment of extracted ground water via airstripping. Thus, for the Conrail Site, permanent solutions, alternative treatmenttechnologies, or resource recovery technologies have been used to the maximumextent practicable.

5. Preference for Treatment as a Principal Element of the Remedy

In comparing alternatives, USEPA did give preference to treatment. That is, USEPAassigned greater weight to the treatment criterion than to the other balancing criteria.However, because of the impracticability of cleaning up the DNAPL source areas todrinking water standards in a reasonable time frame, it was not possible to includetreatment as a principal element of the remedy. However, treatment of the extractedground water via air stripping is included in the selected remedy. Because this remedywill result in hazardous substances remaining on-site during extraction/treatment, areview of the status of the remedy will be conducted within five years of commencementof the remedial action to ensure that the remedy continues to provide adequateprotection of human health and the environment.

^ .1———___________________f/kf/-

William E. Muno, Director DateSuperfund Division

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APPENDIX A

ADMINISTRATIVE RECORD INDEX

U.S. ENVIRONMENTAL PROTECTION AGENCYREMEDIAL ACTION

ADMINISTRATIVE RECORDFOR

CONRAIL RAILTARD SUPERFDND SITE

NO. DATEPAGES

00/00/00

03/01/96

AUTHOR

Schuver, H.,U.S. EPA

West, F.,GroundwaterTechnology

UPDATE #9JULY 31, 2000

RECIPIENT

Van Leeuwen,P., U.S. EPA

Bradley, B.,U.S. EPA

TITLE/DESCRIPTION

FAX Transmission re: 14Groundwater Contaminationand Indoor Air Impacts

Letter re: Construction 6Completion Report for theInterim Water Supply forthe Conrail Railyard Sitew/ Attachments

12/01/97 Dames &Moore

U.S. EPA

12/01/97 Dames &Moore

U.S. EPA

01/26/98 Bradley, B.,U.S. EPA

Menzies, E.,Dames &Moore

09/00/98 Dames &Moore/HSIGeoTrans

U.S. EPA

First Remedial Design/ 101Remedial Action Work Planfor the Conrail RailyardSite: Volume 1 of 2(Text, Tables, Figuresand Appendices A-C)

First Remedial Design/ 441Remedial Action Work Planfor the Conrail RailyardSite: Volume 2 of 2(Appendices D-E)

10Letter re: U.S. EPA'sApproval, with Modifica-tions, of the December 1,1997 Draft First RemedialDesign/Remedial ActionWork Plan for the ConrailRailyard Site

DRAFT First Remedial 222Design/Remedial ActionPreliminary Design Report:Volume I (Text, Tables,Figures and Appendix A)for the Conrail RailyardSite

Conrail Railyard ARUpdate #9

Page 2

NO.

7

DATE

09/00/98

AUTHOR

Dames &Moore/HSIGeoTrans

RECIPIENT

U.S. EPA

IIPTION PAGES

DRAFT First Remedial 1122Design/Remedial ActionPreliminary Design Report:Volume II (Appendix B)for the Conrail RailyardSite

09/00/98 Dames &Moore/HSIGeoTrans

U.S. EPA

12/04/98

10 01/07/99

West, F.,FluorDanielGTI

Tetra Tech,Inc.

11 00/00/99 Dames &Moore

Epps, V.,U.S. EPA

U.S. EPA

U.S. EPA/IDEM

12 01/14/99 Bradley, B.,U.S. EPA

Menzies, M.,Dames &Moore

DRAFT First Remedial 403Design/Remedial ActionPreliminary Design Report:Volume III (Appendix C)for the Conrail RailyardSite

Data Evaluation/Valida- 13tion Report for theThird Quarter 1998 FinalResidential AnalyticalResults at the ConrailRailyard Site

Report: Draft Phase 2 763Benthic MacroinvertebrateInvestigation in theVicinity of the ConrailRailyard Superfund Site

Monthly Progress Reports 54for the Period January-November 1999 for theFirst Remedial Design/Remedial Action WorkPlan for the ConrailRailyard Site

Letter re: U.S. EPA's 2Approval, with Modifica-tions, of the December22, 1998 Draft VaporMonitoring Work PlanAddendum for the ConrailRailyard Site


Page 3

NO. DATE AUTHOR

13

14

01/28/99 . Menzies, E.,Dames &Moore

02/08/99 Wallace, J.,CLEAN,Inc.

RECIPIENT



15

16

02/11/99

02/15/99

17 02/15/99

18 02/17/99

Menzies, E. &G. Armstrong;Dames & Moore

West, F.,ITCorporation

West, F.,ITCorporation

Waters, W.,IDEM



Waters, W.,IDEM

Bradley, B.,U.S. E PA

TITLE/DESCRIPTIONPAGES

FAX Transmission re: 2Additional Vapor Monitor-ing Program Schedule forthe Conrail Kailyard Site

Letter re: CLEAN's 2Comments on the December23, 1998 Addendum to theFirst Remedial Design/Remedial Action andPreliminary DesignReport

Letter re: Revised Vapor 5Monitoring Work PlanAddendum for the ConrailRailyard Site

Data Evaluation/Valida- 12tion Report for theFourth Quarter 1998 FinalGroundwater AnalyticalResults at the ConrailRailyard Site

Data Evaluation/Valida- 10tion Report for theFourth Quarter 1998 FinalResidential AnalyticalResults at the ConrailRailyard Site

Letter re: IDEM's 2Comments on the Addendum tothe First RemedialDesign/Remedial ActionPreliminary Design Reportfor the Conrail RailyardSite


Page 4

NO. DATE AUTHOR RECIPIENT TITLE/DESCRIPTIONPAGES



Letter re: U.S EPA'sComments on the Addendumto the First RemedialDesign/Remedial ActionPreliminary Design Reportfor the Conrail RailyardSite

20 03/02/99 Menzies, E. &G. Armstrong;


Moore

Letter re: SettlingDefendants' Response totl-.S.- EJ2S.' s, CommffJDJ-Js. 0,0.Addendum to the FirstRemedial Design/RemedialAction (RD/RA) PreliminaryDesign Report for theConrail Railyard Site





23 03/17/99 Menzies, E. &G. Armstrong;Dames &Moore


Letter re: U.S. EPA'sApproval of an Extensionfor Submittal of the FinalAddendum to the FirstRemedial Action Prelim-inary Design Report

Letter re: U.S. EPA'sApproval of the January7, 1999 Draft Phase 2-Benthic MacroinvertebrateInvestigation in theVicinity of ConrailRailyard Document withComments on FutureEcological Sampling

Letter re: Round 3 VaporMonitoring Results andRound 4 AdditionalAddresses for the FirstRemedial Design/RemedialAction at the ConrailRailyard Site


Page 5

NO. DATE AUTHOR RECIPIENT TITLE/DBSCRIPTIONPAGES



25 03/23/99 Wallace, J.,CLEAN,Inc.


Letter re: U.S. EPA's(I) Transmission of VaporSampling Results toResidents, (2) Approvalof Round 4 Vapor Monitor-ing in April 1999 and{3} Approval of ProposedList of Additional Resi-dences to be Sampledin Round 4

Letter re: CLEAN'sClarification on Commentsand Concerns on the Decem-ber 23, 1998 Addendum tothe First Remedial Design/Remedial Action and Pre-liminary Design Reportfor the Conrail RailyardSite





Letter re: Schedule for 1Settling Defendants'Response to U.S. EPA'sComments on the Addendumto the Preliminary DesignReport for the FirstRemedial Design/RemedialAction at the ConrailRailyard Site

Letter re: Settling 4Defendants' Response toU.S. EPA's Comments onthe January 7, 1999Ecological Phase 2Assessment Report forthe First Remedial Design/Remedial Action at theConrail Railyard Site


Page 6

AUTHOR


29 05/06/99 Menzies, E. &G. Armstrong;Dames & Moore

RECIPIENT




Letter re: Various Issues (Discussed at the April 7,1999 Meeting Concerning theConrail Railyard Sitew/Attached April 1999Clean Water News (Volume2, Issue 4)

Cover Letter Forwardingthe Revised Addendum tothe Preliminary DesignReport for the FirstRemedial Design/Remedial&n.tvi_o_o- f.o,r. tjxe ConrailRailyard Site w/AttachedTable of Revisions

30 05/07/99 HSI GeoTrans U.S. EPA Preliminary Design.Report Addendum for the

214

31 05/11/99

32 05/2S/99


Wallace, J.,CLEAN,

33 05/28/99 ITCorporation



U.S. EPA

FAX Transmission re: 2Conversion Calculationsfor Carbon Tetrachlorideand Trichloroethene forthe Conrail Railyard Site

Letter re: CLEAN's 2Comments on the May 7,1999 Preliminary DesignReport Addendum for theConrail Railyard Site

Data Evaluation/Valida- 20tion Report for theFirst Quarter 1999 Ground-water Sampling Eventat the Conrail RailyardSite


Page 7

NO. DATE AUTHOR RECIPIENT TITLE/DESCRIPTIONPAGES

34 05/28/99 ITCorporation



U.S. EPA



Data Evaluation/Valida-tion Report for theFirst Quarter 1999 Resi-dential Sampling Eventat the Conrail RailyardSiteLetter re: Vapor Monitor-ing Program w/AttachedSummary of AnalyticalResults for Round 4 forthe Conrail Railyard Site

Letter re: U.S. EPA'sApproval, with Modifca-tions, of the May 6, 1999Preliminary Design ReportAddendum for the ConrailSite w/Attached Site Map

45







Letter re: UpcomingMonitoring and AbatementActivities at the ConrailRailyard Site

Letter re: Results ofVapor Monitoring (Round4) at the Conrail Rail-yard Site

Letter re: SettlingDefendants' Response toU.S. EPA's June 23, 1999Concerning Vapor Issuesat the Conrail RailyardSite


Page 8

NO. DATE AUTHOR RECIPIENT [PTION

G. Armstrong;Dames &Moore

U.S. EPA

41 08/00/99 CLEAN,Inc.

Public

"re":Defendants' Response toU.S. EPA's Comments onthe Preliminary DesignReport Addendum for theFirst Remedial Design/Remdial Action (RD/RA)at the Conrail RailyardSite w/Attached Replace-ment Pages

Clean Water News (Volume2, Issue 5)

42 08/]0/99 Menzies, E. &G. Armstrong;Dames &Moore


Letter re: PreliminaryDesign Concept for VaporMitigation System at10204 Vistula Road forthe Conrail RailyardSite

27

43 08/27/99 Aceto, F.,ITCorporation



45 09/23/99 Muno, W.,U.S. EPA

46 09/28/99 Wallace, J. ,CLEAN,Inc.

Lambert, P.BinghamDana

U.S. EPA


Data Evaluation/Valida- 11tion Report for theSecond Quarter 1999Groundwater SamplingEvent at the ConrailRailyard Site

Letter re: U.S. EPA's 1Conditional Approval forNorfolk Southern toPerform Future Work atthe Conrail Railyard Site

Five Year Review Report 5for the Conrail RailyardSite

Letter re: CLEAN's 25Comments on the Petitionfor a Technical Imprac-ticability Waiver andRequest for RemedyReconsideration for theConrail Railyard Site


Page 9

NO. DATE

47

49

09/28/99

10/00/99

11/04/99

AUTHOR

Menzies, E. &G. Armstrong;Dames &Moore

CLEAN,Inc.


50 11/22/99 Menzies, E.,URS Dames &Moore

51 11/29/99 Aceto, F.,ITCorporation

52 12/07/99 Menzies, E. &G. Armstrong;URS Dames &Moore

RECIPIENT


Public



Bradley, B.,U.S. EPA &K. Herron,IDEM


TITIi*- /DESCRIPTIONPAGES

Vapor Monitoring Progress 23Report for the ConrailRailyard Site w/ AttachedCover Letter

Clean Water News (Volume 42, Issue 6)

Letter re: U.S. EPA's 6Approval, with Modifica-tions of the Vapor Moni-toring Progress Report/60% Design for the ConrailRailyard Site w/ AttachedCLEAN, Inc. Comments

Letter re: Settling 3Parties' Response to U.S.U.S. EPA's Comments on theVapor Monitoring Report/60% Design for the FirstRemedial Design/RemedialAction (RD/RA) for theConrail Railyard Site

Data Evaluation/Valida- 13tion Report for theThird Quarter 1999 FinalResidential AnalyticalResults and GroundwaterAnalytical Results at theConrail Railyard Site

95% Design Report for 22the Conrail Railyard Sitew/ Attached Cover Letter


Page 10

NO. DATE AUTHOR


RECIPIENT


54 00/00/00 URS Dames &Moore

U.S. EPA/IDEM

55

56

57

01/23/00

02/00/00

02/02/00

Menzies, E.,URS Dames &Moore

CLEAN,Inc.

HSI GeoTrans,Inc./Dames &Moore


Public

U.S. EPA


Letter re: U.S. EPA's 5Comments on the August13, 1999 Petition for aTechnical ImpracticabilityWaiver and Request forRemedy Reconsiderationfor the Conrail RailyardSite

Monthly Progress Reports 10for February and March2000 for the FirstRemedial Design/RemedialAction Work Plan for theConrail Railyard Site

Letter re.: Action for 44Spring Street Propertiesw/ Attached ResidentialSampling Results

Clean Water News (Volume 42, Issue 7)

Petition for a Tech-nical ImpractacabilityWaiver and Request forRemedy Reconsiderationfor the Conrail RailyardSite

138

58 02/03/00 Menzies, E.,URS Dames &Moore


Cover Letter Forwarding 2Revised Groundwater RemedyReconsideration Requestand Technical Impractica-bility Waiver Petitionfor the Conrail RailyardSite

59 02/08/00 Van Leeuwen,P., U.S. EPA


Memorandum re: IndoorAir Action Levels forVolatiles at the ConrailRailyard Site


Page 11

NO. DATE AUTHOR

60 02/24/00 Dames &Moore


RECIPIENT

U.S. EPA

U.S. EPA


Residential and Monitor- 17ing Well Groundwater DataReport for the FourthQuarter 1999 at theConrail Railyard Site

Memorandum re: CLEAN'S 1Comment on the February3, 2000 Petition for aTechnical ImpracticabilityWaiver and Request forRemedy Reconsiderationfor the Conrail RailyardSite

62 03/06/00 Herron, K.,IDEM


Letter re: IDEM's 5Comments on the Petitionfor a Technical Impractica-bility Waiver and Requestfor Remedy Reconsiderationat the Conrail RailyardSite

63 04/L4/00 Bradley, B.,U.S. EPA

Menzies, E.,URS Dames &Moore

64 05/00/00 U.S. EPA

65 07/31/00 U.S. EPA

66 00/00/00 U.S. EPA

Public

Public

Public

Letter re: U.S. EPA'sComments on the February3, 2000 Petition for aTechnical ImpracticabilityWaiver and Remedy RequestConsideration for theConrail Railyard Site

Proposed Plan for theConrail Railyard Site

Responsiveness Summaryfor the Conrail RailyardSite

Record of Decision Amend-ment for the ConrailRailyard Site (PENDING)

APPENDIX B

RESPONSIVENESS SUMMARY

The public comment period for the proposed amended ground water remedy for theConrail Superfund Site in Elkhart, Indiana began on May 11, 2000 and ended on June12, 2000. EPA held a public meeting regarding this proposed remedy change on May 11,2000. Oral comments were received during the public meeting, and four written publiccomments were received by EPA subsequent to the public meeting.

The comments, both oral and written, are addressed below:

COMMENT: One commenter stated that soil extraction should be used on the drag strip.

EPA RESPONSE: The cleanup remedy for the drag strip has not yet been decided, andsoil vapor extraction will be considered along with other possible alternatives, such asexcavation and off-site disposal and hydraulic containment.

COMMENT: One commenter asked for unlimited testing of the leading edges of theground water contaminant plumes.

EPA RESPONSE: Periodic testing (monitoring) of the ground water is included in theselected remedy; however, unlimited testing is not necessary since the plume boundariescan be determined fairly accurately with the monitoring system that is already in place.

COMMENT: One commenter requested that a meeting be set up with local real estateagents so that prospective property buyers in the area of the Conrail Site would be madeaware of the fact that it is a Superfund site and the contamination that is present.

EPA RESPONSE: EPA is willing to participate in any such meeting. Currently, in ElkhartCounty, newly-constructed homes are required to be hooked up to the city water supply,and the builders/developers are required to collect vapor samples in the basements ofthe new homes so that any potential contaminant vapor problems will be identified.

COMMENT: One commenter wanted Crawford Ditch to be tested before any treatedwater was discharged to it.

EPA RESPONSE: EPA has written the portion of the selected remedy dealing withdischarge of treated water as "treated water will be discharged in a manner that will notadversely impact Crawford Ditch and/or the St. Joseph River". The original language,which specifically stated that discharge was to be to Crawford Ditch, was changed inresponse to public comments, including this one, and this new language addresses the

-2-

commenters' concerns.

COMMENT: One commenter asked if the owner of the drag strip will be held accountablefor the pollution that is found on the drag strip.

ERA RESPONSE: The way that the legal agreement between Conrail, American PremierUnderwriters (formerly Penn Central), and EPA is structured, Conrail and AmericanPremier Underwriters (APU) will be responsible for performing any cleanup activitiesrequired at the drag strip; however, Conrail and APU are free to take any actions they sodesire to recover any costs of the drag strip cleanup from the current owner of the dragstrip.

COMMENT: The Citizen's League for Environmental Action Now (CLEAN) submitted thefollowing comments to the proposed Alternative 2:

Comment A: CLEAN suggested that a full characterization of Crawford Ditch bedone before its potential use as a discharge conveyance for treated ground water.

EPA Response: With the language change in the selected remedy that does notspecify that treated ground water must be discharged to Crawford Ditch, but ratherin a manner that does not adversely impact Crawford Ditch and the St. JosephRiver, this comment may be moot. However, if treated ground water ultimatelydoes get discharged to Crawford Ditch, EPA is requiring that the ResponsibleParties demonstrate that such discharge will not adversely affect Crawford Ditch orthe St. Joseph River. This demonstration will be included as part of the designpackage for the ground water remedy, and CLEAN can raise this issue at that timevia their design comments.

Comment B: CLEAN expressed concern that the boundaries of the ConrailSuperfund Site not be changed, and used the LaRue Street plume as an exampleof an area of the Site that had not been addressed for some time.

EPA Response: The definition of the Superfund Site is contained in the legalagreement (Consent Decree) between Conrail, APU, and EPA. This definition willnot be changed. The LaRue Street plume is included within this site definition,and monitoring of the LaRue Street plume will continue as part of the ground watermonitoring program for the Site.

Comment C: CLEAN stated that contingency plans should include additional vaportesting, especially in the area of the proposed containment wells since theextraction may create local changes that may actually increase vapor levels.

-3-

EPA Response: The vapor testing program implemented by Conrail was designedto address the homes with the highest risk of having vapor problems. Thesehomes had high levels of contamination in the ground water, had basementsand/or crawl spaces, and/or were located in an area with a shallow water table.The testing indicated that a vapor problem (carbon tetrachloride) existed only in asmall area around Lehman, Vistula, and Ash Roads. Coupled with the results ofsoil gas testing on the drag strip, EPA has concluded that the drag strip is likelythe main source of the carbon tetrachloride vapors found in these homes.

EPA does not feel that the ground water containment system on the rail yard willimpact vapor levels in the homes immediately north of U.S. Highway 33. First,these homes are several hundred feet away from the proposed containment wells,and the cones of depression may not reach that far. Second, the extraction ofground water would tend to lower, not increase, contaminant concentrations in theshallow zone of the aquifer.

Given the vapor results to date, and the results of other vapor tests that have beenconducted by CLEAN, EPA does not feel that additional vapor testing outside ofthe area downgradient from the drag strip is warranted at this time.

COMMENT: The St. Joseph River Basin Commission (SJRBC) submitted the followingcomments to the proposed alternative 2:

Comment A: The SJRBC recommended that enough monitoring wells be installedto thoroughly assess the potential movement of contaminants at the Site,especially in the area around track 69, and that a schedule of monitoring bedeveloped to allow timely detection of any breach in the containment system.

EPA Response: All of the SJRBC's recommendations are addressed by theselected remedy. Ground water monitoring will continue under the selectedremedy, with approximately three well nests being added in the area immediatelydowngradient from track 69. Also, the selected remedy requires that acontingency plan be developed to prescribe action in the event that thecontainment system does not perform adequately. The monitoring schedule willbe finalized during the remedial design for the selected remedy, and EPA willwelcome any comments regarding the frequency of monitoring at that time.

Comment B: The SJRBC recommended that containment wells also be placed atthe eastern contaminant plume (La Rue Street plume) and that hydrologicmodeling be performed regarding the discharge of treated ground water toCrawford Ditch. The SJRBC also brought up the possibility of allowing infiltrationof the treated ground water on the rail yard, rather than discharge to CrawfordDitch.

-4-

EPA Response: Since there are no Dense Non-Aqueous Phase Liquids (DNAPLs)in the eastern (LaRue Street) contaminant plume, there is no need to placecontainment wells in this area. The selected remedy contains language that isdifferent than that in the proposed plan, which allows treated ground water to bedischarged in a manner that will not adversely impact Crawford Ditch and/or theSt. Joseph River. Thus, the suggestion of the SJRBC regarding infiltration, is anoption that could be used for disposition of treated ground water. If this water isdischarged to Crawford Ditch, hydrologic monitoring would be performed in theRemedial Design phase.

Comment C: The SJRBC encouraged continued investigation and remediation ofthe Drag Strip area, with a goal of eliminating this area as a possible source ofground water contamination.

EPA Response: EPA appreciates the statement of support for selected remedy,which includes the provision for cleanup of the Drag Strip.

Comment D: The SJRBC suggested that, upon periodic review, all new technologyoptions for remediation of the site be considered that would increase and hastensuccessful elimination of the contamination at the Conrail Site.

EPA Response: A provision for trying out some promising new technologies for theDNAPL areas is included in the Petition for a Technical Impracticability Waiver thatwas written by the Settling Defendants, and EPA will look at issues such as theone raised here during its periodic five-year reviews for the Site, which arerequired for any site where wastes are left in place. The next five-year review isscheduled for 2004.

Documents

Record of Decision Amendment to Change Groundwater …change the remedy at the Conrail Site fundamentally altered the basic features of the selected remedy, and this necessitated the