SECOND FIVE-YEAR REVIEW REPORT

JACKSON TOWNSHIP LANDFILL SITE

JACKSON TOWNSHIP, OCEAN COUNTY, NEW JERSEY

Prepared By:U.S. Environmental Protection Agency

Region IINew York, New York

September 2005

Executive Summary

The September 1994 Record of Decision (ROD) for the JacksonTownship Landfill Site provided for ‘No Further Action withMaintenance and Monitoring’ to be conducted at the Site pursuantto CERCLA. The ‘No Further Action with Maintenance andMonitoring’ remedy was based upon EPA’s and NJDEP’s determinationthat conditions at the Site posed no current or potential threatto human health and the environment. In addition to the NoFurther Action with Maintenance and Monitoring remedy, the RODprovided for the closure of the landfill as required by NewJersey regulations. Actions necessary to comply with NJDEP SolidWaste Landfill Closure requirements included; installation of asand and gravel cap; detention basins, and post-closuremonitoring of groundwater and air.

The trigger for this second five-year review was the completionof the first five-year review in September 1999. The assessmentof this second five-year review found that the remedy iscontinuing to function as intended and is protective of humanhealth and the environment.

Five-Year Review Summary Form

SITE IDENTIFICATION

Site name (from WasteLAN): Jackson Township Landfill

EPA ID (from WasteLAN): NJD980505283

Region: 2 State: NJ City/County: Jackson Township, Ocean County

SITE STATUS

NPL status: G Final O Deleted G Other (specify)

Remediation status (choose all that apply): G Under Construction O Constructed O Operating

Multiple OUs?* G YES O NO Construction completion date: September 1994

Has site been put into reuse? G YES � NO G N/A

REVIEW STATUS

Lead agency: G EPA � State G Tribe G Other Federal Agency

Author name: Mary Anne Rosa

Author title: Rem edial Project Manager Author affiliation: EPA

Review period:** 9/1999 to 7/2005

Date(s) of site inspection: January 12, 2005 and June 29, 2005

Type of review:

� Post-SARA G Pre-SARA G NPL-Removal onlyG Non-NPL Remedial Action Site G NPL State/Tribe-leadG Policy G Regional Discretion

Review number: G 1 (first) � 2 (second) G 3 (third) G Other (specify)

Triggering action:

� Actual RA Onsite Construction at OU #1 9 Actual RA Start at OU# 1

9 Construction Completion � Previous Five-Year Review Report

9 Other (specify)

Triggering action date (from WasteLAN): 9/14/1999

Does the report include recommendation(s) and follow-up action(s)? � yes G no

Is the remedy protective of the environment? O yes G no

* [“OU” refers to operable unit.]** [Review period should correspond to the actual start and end dates of theFive-Year Review in WasteLAN.]

Five-Year Review Summary Form (continued)

Remedy Assessment SummaryAccording to the data reviewed and the site inspection, theremedy is functioning as intended by the ROD and the JudicialConsent Order (JCO). The landfill cap prevents direct exposure;the gate and fencing restrict access to the site. The fence andgate are in good condition and restrict unauthorized access tothe site. There are no drinking water wells within thecontaminated plume. There have been no changes in the physicalconditions of the site that would affect the protectiveness ofthe remedy.

Issues, Recommendations, and Follow-Up ActionsAs a result of this review, EPA has determined that althoughNJDEP has been providing oversight of this site, pursuant to theJCO, the last round of groundwater data collected was inSeptember 1999. Therefore, there is not sufficient groundwaterdata available to accurately assess the presence of constituentsin groundwater at this time. In order to characterize thecurrent nature and extent of the contamination associated withthe site, the Township, with NJDEP oversight, should conduct thefollowing activities:- perform a well assessment to determine which wells still existand which are serviceable. It is possible that new wells willhave to be installed. - conduct an annual groundwater monitoring program including allavailable wells and analyze for Target Compound List (TCL)volatiles and semi-volatiles, Target Analyte List (TAL) metals,sulfate, chlorides and water levels (pursuant to the JCO); - properly dispose of the barrels of Investigation-Derived Waste(IDW) remaining from the installation of the methane flaringwells; and- the methane gas monitoring program should also continue tomonitor and assess the methane gas migration from the landfill,under NJDEP oversight. The Township should continue to managethe operation and maintenance program for the landfill, includingthe quarterly site inspections, routine cap maintenance and fenceinspection.

Protectiveness StatementThe selected remedy, ‘No Further Action with Maintenance andMonitoring’ protects human health and the environment in the shortterm. However, in order for the remedy to be protective in thelong term, additional groundwater monitoring is required. Thereare no exposure pathways that could result in unacceptable risksand none expected as long as the New Jersey Department ofEnvironmental Protection (NJDEP) properly enforces its Stateauthorities, and Jackson Township properly maintains and monitorsthe landfill. In order to assure that the remedy is protective inthe long term, additional groundwater monitoring will need to beperformed and the data evaluated.

Table of Contents

I. Introduction . . . . . . . . . . . . . . . . . . . . . . . 1II. Site Chronology . . . . . . . . . . . . . . . . . . . . . 1III. Background . . . . . . . . . . . . . . . . . . . . . . . . 2

Site Location and Description . . . . . . . . . . . . . . 2Geology/Hydrology . . . . . . . . . . . . . . . . . . . . 3Land and Resource Use . . . . . . . . . . . . . . . . . . 3History of Contamination . . . . . . . . . . . . . . . . . 3Initial Response . . . . . . . . . . . . . . . . . . . . . 3Basis for Taking Action . . . . . . . . . . . . . . . . . 4Enforcement Activities . . . . . . . . . . . . . . . . . . 4

IV. Remedial Action . . . . . . . . . . . . . . . . . . . . . 4Remedy Selection . . . . . . . . . . . . . . . . . . . . . 4Remedy Implementation/Landfill Closure Plan . . . . . . . 5Operation and Maintenance . . . . . . . . . . . . . . . . 5Landfill Gas Monitoring . . . . . . . . . . . . . . . . . 5

V. Progress since last Five Year Review . . . . . . . . . . . 6VI. Five-Year Review Process . . . . . . . . . . . . . . . . . 6

Administrative Components . . . . . . . . . . . . . . . . 6Community Notification and Involvement . . . . . . . . . . 6Document Review . . . . . . . . . . . . . . . . . . . . . 7Data Review . . . . . . . . . . . . . . . . . . . . . . . 7Groundwater Monitoring . . . . . . . . . . . . . . . . . . 7Landfill Gas Monitoring . . . . . . . . . . . . . . . . . 7Site Inspection . . . . . . . . . . . . . . . . . . . . . 8Interviews . . . . . . . . . . . . . . . . . . . . . . . . 9Institutional Controls . . . . . . . . . . . . . . . . . . 9

VII. Remedy Assessment . . . . . . . . . . . . . . . . . . . 10Question A: Is the remedy functioning as intended by the

decision documents? . . . . . . . . . . . . . . 10Question B: Are the exposure assumptions, toxicity data,

cleanup levels, and remedial action objectives(RAOs) used at the time of the remedy selectionstill valid? . . . . . . . . . . . . . . . . . . 10

Question C: Has any other information come to light that couldcall into question the protectiveness of theremedy? . . . . . . . . . . . . . . . . . . . . 16

Remedy Assessment Summary . . . . . . . . . . . . . . . . 16VIII. Issues, Recommendations and Follow-Up Actions . . . . . . 16IX. Protectiveness Statement . . . . . . . . . . . . . . . . 17X. Next Review . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 1 - Site Map . . . . . . . . . . . . . . . . . . . . . 18Appendix A - List of Documents Reviewed . . . . . . . . . . . 19Appendix B - List of Acronyms . . . . . . . . . . . . . . . . 20

I. Introduction

The U.S. Environmental Protection Agency (EPA), Region II, hasconducted a Five-Year Review of the remedial actions implementedat the Jackson Township Landfill Superfund Site (Site), located inJackson Township, Ocean County, New Jersey. This five year reviewwas conducted pursuant to Section 121 (c) of the ComprehensiveEnvironmental Response, Compensation, and Liability Act (CERCLA),as amended, 42 U.S.C. §9601 et seq. and 40 CFR 300.430(f)(4)(ii),and in accordance with the Comprehensive Five-Year ReviewGuidance, OSWER Directive 9355.7-03B-P (June 2001). The NewJersey Department of Environmental Protection (NJDEP) is the leadAgency for this Site. This Five-Year Review report documents theresults of the review.

This is the second five-year review for the Jackson TownshipLandfill. The triggering action for this review is the date ofthe first Five-Year Review, which was completed on September 14,1999.

II. Site Chronology

Table 1 summarizes Site-related events from discovery to thepresent.

TABLE 1 - Chronology of Site Events

Event Date(s)

Jackson Township purchases the property from theGlidden Corporation

1972

Jackson Township begins accepting municipal wastes atthe landfill

April 1972

Citizens complain about quality of water (i.e., taste,smell, clarity, rashes)

1977

NJDEP investigates and determines several domesticwells contaminated

1977

NJDEP orders Jackson Township to stop disposing ofliquid wastes at the landfill

1978

Citizen lawsuit results in a municipal water systemextension to properties affected

1980

Landfill closed by order of Superior Court of NewJersey

February 1980

Groundwater sampling in twenty-two monitoring wellsand eight residential wells

December 1981, February 1982

Site placed on the National Priorities List December 1982

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Remedial Action Master Plan completed 1984

NJDEP issues a New Jersey Pollution DischargeElimination System permit (NJPDES) in order to monitorgroundwater affected by the site

1985

Another round of groundwater sampling conducted 1985

Judicial Consent Order (JCO) between NJDEP and JacksonTownship (Township to reimburse NJDEP $110,000 and toconduct an investigation and remediation of thelandfill)

1988

Township conducts Remedial Investigation 1989 - 1990

Final Remedial Investigation approved 1991

Jackson Township conducts Risk Assessment 1993

Groundwater sampling and air/gas monitoring conducted October 1993

Proposed Plan issued March 3, 1994

NJDEP, with EPA concurrence, issues a “No FurtherAction with Maintenance and Monitoring” Record ofDecision

September 1994

Jackson Township Landfill Closure Plan June 1995

EPA deletes the Site from the NPL September 1995

Closure and Post-Closure Plan approval by NJDEP February 1996

First Five-Year Review completed September 1999

Jackson Township’s contractor submits groundwaterand air monitoring data

January 2000

Revised Closure and Post-Closure Plan approval byNJDEP authorizing the construction of the LandfillGas collection system improvements

September 2004

III. Background

Site Location and Description

The Jackson Township Landfill Site (see Figure 1) is located offLakehurst Avenue in Jackson Township, Ocean County, New Jersey. The landfill is situated on 135 acres of land in a regionalreserve known as the New Jersey Pine Barrens, or Pinelands. Ofthis area, approximately 20 acres were previously used for thedisposal of various liquid, semi-liquid, and solid wastes. Thelandfill is surrounded by residential properties to the north,south and west. To the east, the landfill borders large sand

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piles and a quarrying operation.

Geology/Hydrogeology

The geology/hydrogeology at the Site consists of sands which gradeto silty sand and clay at increasing depth within the major waterbearing formation, the Cohansey Formation. The Cohansey Formationhas two integral water bearing zones in the area of the landfill,the Upper and Lower Cohansey Formation. Groundwater flow in theUpper Cohansey is generally in a south-southwesterly direction. Lower Cohansey Formation water flow is generally toward the south.

History of Contamination

Glidden Corporation owned the property comprising the Site, andconducted surface mining operations within the property limits from 1961 to 1972 to recover the mineral ilmenite which is used asa pigmentation agent. In 1972, Glidden Corporation sold theproperty to Jackson Township. Jackson Township then beganaccepting municipal wastes at the landfill under a State permit toreceive sewage sludge, septic tank wastes and solid wastes. Landfill operations commenced in the western portion of theproperty with the landfill accepting bulk liquid and semi-liquidcoffee wastes, household refuse, tree stumps, construction debris,junked cars and liquid septage. Much of the liquid waste disposedof in the landfill contained volatile organic contaminants (VOCs)such as methylene chloride.

Initial Response

In 1977, there were multiple complaints associated with the use ofarea groundwater. Subsequent analysis of area groundwater orderedby the New Jersey Department of Environmental Protection concludedthat a segment of the Cohansey aquifer and several domestic wellshad been contaminated by the landfill. Contaminants detected inon-site monitoring wells and off-site potable wells includedbenzene, chloroform, methylene chloride and 1,1,1-trichloroethylene. In 1978, NJDEP ordered Jackson Township tostop disposing of liquid wastes at the landfill. In 1980, thelandfill was closed by order of the Superior Court of New Jersey. Furthermore, in 1980, a citizens lawsuit resulted in a municipalwater system extension to residents affected or potentiallyaffected by the landfill. The Site was proposed to be included onthe National Priorities List (NPL) on December 30, 1982 and wasincluded on the NPL on September 8, 1983.

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Basis for Taking Action

A Remedial Action Master Plan (RAMP) for the Site was completed inNovember 1984. The RAMP concluded that since no soil, surfacewater, sediment or biota sampling had been conducted at the Site,and because of discrepancies in groundwater sample handlingprocedures and sample handling methods, additional investigationof the Site was necessary.

Enforcement Activities

In 1988, the NJDEP and Jackson Township entered into a JudicialConsent Order (JCO). Pursuant to this JCO, Jackson Township wasrequired to conduct further site investigation and remediation ofthe landfill, as necessary. In 1989 and 1990, Jackson Townshipconducted a Remedial Investigation (RI) at the Site. The Final RIReport was approved by NJDEP and EPA in 1991. Results of the RIindicated that groundwater contaminant levels had declinedsignificantly since the landfill had been closed.

In addition, Jackson Township performed a Risk Assessment. TheFinal Risk Assessment Report was approved by NJDEP and EPA in July1993. It determined that the Site did not present an unacceptablethreat to human health or the environment.

Based upon the results of the RI and the findings of the RiskAssessment, NJDEP signed a “No Further Action with Maintenance andMonitoring” ROD for the Site, with EPA’s concurrence, on September27, 1994. Subsequently, EPA and NJDEP deleted the Site from theNPL on September 13, 1995.

IV. Remedial Action

Remedy Selection

In the September 1994 ROD, the NJDEP selected the No FurtherAction with Maintenance and Monitoring remedy for the JacksonTownship Landfill Site. Based on the findings of the RI and RiskAssessment, the NJDEP and EPA determined that conditions at theSite posed no current or potential threat to human health and theenvironment.

Pursuant to the 1988 JCO, and the 1994 ROD, the final landfillclosure would be conducted in a manner consistent with the NJDEPSolid Waste Landfill requirements; thereby satisfying allnecessary regulatory requirements for the Site. Actions necessaryto comply with NJDEP Solid Waste Landfill Closure requirementsincluded; installation of a soil cap and detention basins, andpost-closure groundwater and air monitoring.

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Because groundwater samples collected at the Site containedconstituents at concentrations which exceeded NJDEP’s Ground WaterQuality Standards in a few instances, a Five-Year Review wasconducted pursuant to CERCLA and the NCP.

Remedy Implementation/Landfill Closure Plan

In June 1995, Jackson Township’s consultant, GeoSystems, Inc.,submitted the Jackson Township Landfill Closure Plan to the NJDEP,pursuant to the State’s landfill closure requirements. InFebruary 1996, NJDEP Approved the Closure Plan. The LandfillClosure Plan included, but was not limited to, the design andimplementation of the following:

- installation of final cover;- a soil erosion and sediment control plan;- groundwater monitoring;- landfill gas monitoring;- a methane gas venting or evacuation system;- installation of a facility access control system (i.e.,

fence); and- post-closure operation and maintenance activities.

Operation and Maintenance(O&M)

Jackson Township is responsible for conducting operation andmaintenance activities at the Site, under oversight of the NJDEP. Since 1995, the Township has conducted landfill post-closuremaintenance activities which include visually inspecting the capand runoff drainage channels, inspecting locks and casings ofmonitoring wells, clearing vegetation from the cap and drainagechannels, and performing sampling and analysis for the long-termgroundwater and methane gas monitoring program. Monthly SiteInspection reports are submitted to the State pursuant to the 1988Judicial Consent Order between the Township and NJDEP.

Site inspections are conducted by the Township’s contractor and/orTownship personnel to ensure that the fence is in good repair andto look for signs of trespass. Any deficiencies which may benoted, such as plant growth requiring clearing and grubbing orremoval of debris and minor fence repair, are addressed quickly bythe Township.

Landfill Gas Monitoring

As part of the 1995 Landfill Closure Plan, permanent monitoringlocations were constructed to monitor methane gas which couldmigrate laterally from the landfill. Methane gas surveys were tobe performed on a quarterly basis, in accordance withN.J.A.C.7:26-2A.8(h)9, at the fixed monitoring well locations

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around the perimeter of the landfill. If landfill gas is detectedoff-site at or above 25% of the lower explosive limit (LEL), thena corrective action plan, including a time table forimplementation, shall be implemented.

Since 1995, Jackson Township’s consultant has been performingquarterly monitoring of methane levels at the landfill. Since2000, the concentrations of methane gas in the southwest corner ofthe Site have increased and have begun to migrate off-site in alateral direction. Jackson Township conducts monthly Landfill GasSurveys which include methane gas sampling at 39 locations.

V. Progress Since the Last Review

The first five-year review was conducted in September 1999,pursuant to OSWER Directives 9355.7-02 (1991), 9355.7-02A (1994)and 9355.7-03A (1995). The first Five-year Review recommendedthat the on-site monitoring program continue. Routine O&Mactivities have been ongoing, under NJDEP oversight; however, thelast round of groundwater samples was collected six years ago. Itis now recommended that sampling of the monitoring wells beconducted annually and analyzed for the parameters listed in theJCO for the next five years. This five-year review concluded thatthe implemented remedy protects public health and the environmentin the short term; however, additional groundwater monitoringshould be conducted to ensure that the remedy is protective in thelong term.

VI. Five-Year Review Process

Administrative Components

The five-year review team consisted of Mary Anne Rosa, RemedialProject Manager; Grant Anderson, Hydrogeologist; Julie McPherson,Risk Assessor; and Kevin Psarianos, NJDEP; Pat Seppi, CommunityInvolvement Coordinator.

Community Notification and Involvement

EPA notified the community of the initiation of the five-yearreview process by publishing a notice in the Asbury Park Press onMay 14, 2005. The notice indicated that EPA would be conducting afive-year review of the remedy at the Jackson Township Landfill toensure the remedy remains protective of public health and isfunctioning as designed. The notice included the RPM’s addressand telephone number for questions related to five-year reviewprocess. In addition, the notice indicated that once the five-year review is completed, the results will be made available tothe public at the Jackson Township Municipal Building located at

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RD 4, Box 1000, Jackson, New Jersey 08527 and EPA Records Center.The RPM has not been notified of any concerns about the Site basedupon this public outreach. Document Review

The list of documents, data, and information which were reviewedin completing this second five-year review are found in AppendixA.

Data Review

The data reviewed included the data from the first five-yearreview and subsequent monitoring data.

Groundwater Monitoring

As part of NJDEP’s Solid Waste Landfill Closure Requirements, agroundwater sampling event was conducted at the Site in September1999. Samples were collected from nine groundwater monitoringwells. The results of this sampling event, submitted to NJDEP inJanuary 2000, indicate that aluminum, iron, lead, manganese,cadmium, arsenic and chromium are still present in groundwater atlevels which exceed NJDEP’s Ground Water Quality Standards (GWQS). However, the Risk Assessment determined that exposure to theelevated levels of aluminum, iron, manganese, cadmium, arsenic andchromium present at the Site is unlikely to result in an elevatedhuman health risk.

Lead was detected at elevated levels in one well (MW-202) which islocated upgradient of the former disposal areas at the Site andone downgradient well (MW-305S).

In 1997, mercury was detected above its GWQS in two wells (MW-303Dand MW-304D) screened in the deep aquifer downgradient of theSite. The 1999 data indicates that the mercury contamination hasdecreased in these two wells to levels at or below the GWQS level. It should be noted that mercury was not detected at elevatedlevels in on-site groundwater samples or in soil samples collectedduring the RI, and is not believed to be related to the Site. Methylene chloride was detected at an estimated concentrationabove its GWQS in one on-site well, but was not detected in otheron-site or off-site wells.

Landfill Gas Monitoring

Since 2000, the concentrations of methane gas in the southwestcorner of the site have increased and have begun to migrate off-site in a lateral direction. Jackson Township’s consultant, T&M

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Associates, conducts monthly Landfill Gas Surveys which includemethane gas sampling at 39 locations: 23 gas monitoring wells, 14slam bar sampling locations, and two flare locations. Gasmonitoring wells are generally located along the propertyboundary. Slam bar samples and the flares are located along thesouthwest border of the landfill.

Methane gas in excess of 25% LEL was detected in seventeen on-sitegas sampling locations. The number of gas monitoring wells andgas sampling points with methane gas exceeding 25% LEL hasincreased since October 2004.

Off-site gas sampling was performed from the landfill propertyboundary in a southerly direction toward Lakehurst Avenue untilzero percent methane was detected. Methane gas in excess of 25%LEL was detected in nine on-site gas monitoring wells located inthe southwestern corner of the landfill. It has been determinedthat methane gas has migrated approximately 80 feet from thelandfill property. The Township will continue to perform on-siteand off-site testing periodically. Trenches to collect andmitigate the methane gas release may be constructed if the methanelevels increase. The Township is working with NJDEP to determinethe appropriate measures to address the methane gas problem.

Site Inspection

The Site inspections were conducted on January 12, 2005 and June29, 2005, by EPA representatives, the Jackson Township Director ofPublic Works, and a representative from the Township’s consultantfirm, T&M Associates. The purpose of the Site inspections was toassess the protectiveness of the remedy. The fence surroundingthe Site remains intact and there are no visible signs oftrespassing onto the Site. The landfill cap is properly maintained. No significant soil erosion was evident at the Site.

All the engineering controls appear intact and in good condition. Jackson Township’s consultant, T&M Associates, has been conductingquarterly inspections of the landfill and performing the quarterlymethane gas monitoring program. The inspection activities includea description of the landfill cover, condition of the drainage anddetention basins, conditions of monitoring well caps and casings,and perimeter fence condition. The inspection reports aresubmitted to the NJDEP.

As a result of this review, EPA determined that the last round ofgroundwater data collected was in September 1999. However,pursuant to the JCO, the Township under NJDEP oversight, shouldhave been collecting groundwater data annually. EPA believes, andwill recommend to NJDEP, that the groundwater monitoring program

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be implemented immediately and that the Township conduct aninventory of residential areas in the vicinity of the Site toverify connection to the municipal water supply.

With the permission of Jackson Township, a model airplane clubutilizes a small area in the southeastern corner of the landfillcover for its aeromodeling activities. This use of a portion ofthe landfill cover is consistent with the selected remedy whereprotective measures remain in place.

Interviews

The Site remedy was discussed with State program representativesand Jackson Township representatives. The requirements ofensuring the protectiveness of the Site by maintaining thelandfill cap, perimeter fence and monitoring was discussed withthe Director of Public Works for Jackson Township.

NJDEP and Jackson Township are aware that the groundwatermonitoring program has lapsed during the last five years and haveindicated that the groundwater monitoring program would beginagain shortly.

Institutional Controls

The 1994 ROD, issued by NJDEP with EPA concurrence, selected "NoFurther Action with Maintenance and Monitoring" as the remedy. This remedy relied on the containment remedy and the continuedmaintenance and monitoring of the landfill, under State programauthorities, to protect public health and the environment. In1988, the NJDEP and Jackson Township entered into a JudicialConsent Order. Pursuant to the 1988 JCO and the 1994 ROD, thefinal landfill closure was conducted in a manner consistent withthe New Jersey Solid Waste Management Act (NJSWMA) requirements;thereby satisfying all necessary regulatory requirements for theSite.

While institutional controls were not included in the ROD, severalSite controls are in place that assure that the selected remedyremains in place. First among these non-CERCLA controls are thelandfill closure requirements implemented under NJSWMA, whichdirected the appropriate closure methods for the landfill andstill serves as a controlling regulatory authority for post-closure decisions. The Post-Closure Monitoring and MaintenancePlan is being implemented to satisfy the requirements of theNJSWMA.

The landfill property is owned and maintained by Jackson Township. As part of this Five-Year Review, EPA evaluated the conditions of

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the JCO and concluded that it was still in place and served as anacceptable enforcement tool to assure the continued operation andmaintenance of the remedy.

The ROD did not require groundwater use controls, and reliesinstead on a monitoring program to identify groundwatercontaminant migration that may threaten public health. JacksonTownship indicated to EPA that residences in the vicinity of thesite are supplied by the public water system. VII. Remedy Assessment

Question A: Is the remedy functioning as intended by the decisiondocuments?

Yes, the remedy appears to be functioning as intended in the ROD.The landfill was closed in 1995, pursuant to State regulations andthe JCO. Currently, the land use downgradient of the Site isprimarily residential. All residents downgradient of the Site areconnected to the municipal public supply; therefore, the exposurepathway has been interrupted.

Question B: Are the exposure assumptions, toxicity data, cleanuplevels, and remedial action objectives used at the time of theremedy still valid?

Based on current information, potable water is supplied by amunicipal water supplier. Therefore, no exposure pathways forgroundwater are complete.

A fence is present around the perimeter of the Site to restrictaccess. In addition, a soil and washed gravel cap covers theSite. The remedy remains protective since routes of exposure(i.e., ingestion, inhalation and dermal contact with contaminatedsoil) have been interrupted to potential receptors.

Some exposure pathways were not evaluated in the original riskassessment (1993). However, it is not anticipated that thesechanges would affect the remedy. Some chemical-specific toxicityvalues have changed since the Site was originally assessed. Inorder to account for changes in toxicity values since the baselinehuman health risk assessment was performed, the maximum detectedconcentrations of the contaminants of concern (COCs) identifiedduring the 1999 groundwater sampling event were compared to theirrespective Region 9 Preliminary Remediation Goals (PRGs) - TapWater Criteria, New Jersey Groundwater Quality Standards (NJGWQS)and their respective National Primary Drinking Water StandardMaximum Contaminant Levels (MCLs). The MCL is the highest levelof contaminant that is considered protective in drinking water.

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MCLs are promulgated standards that apply to public water systemsand are intended to protect human health by limiting the levels ofcontaminants in drinking water. PRGs are a human health risk-based value that is equivalent to a cancer risk of 1 x 10-6 or ahazard index of 0.1. This analysis indicates that maximumdetected concentrations of Arsenic, Lead, Mercury, Aluminum,Cadmium, Chromium, Iron, Manganese and Vanadium exceeded theirrespective MCLs or PRGs in 1999 (Table 1). A groundwater sampling event was conducted at the Site inSeptember 1999. Samples were collected from nine groundwatermonitoring wells. Aluminum was detected above its respective MCLand NJGWQS in all of the sampled monitoring wells during thisevent; however, the concentrations did not exceed the non-cancerthreshold (HI=1).

Arsenic was detected above its NJGWQS standard in only one well(MW-305S), which is the furthest downgradient sampling locationincluded in this sampling event. Arsenic was not detected at anyother sampling location during this sampling event.

Cadmium was detected above its respective MCL and NJGWQS at onlyone sampling location during this sampling event (MW-305S). Theconcentrations of cadmium detected in the other monitoring wellsat Jackson Township did not exceed the respective MCL or PRG(HI=1) for cadmium during this sampling event.

Chromium was detected above its respective MCL and PRG at only onesampling location during this sampling event (MW-305S). Chromiumwas only detected in two other monitoring wells at levels whichdid not exceed its respective MCL or PRG.

Iron exceeded its respective MCL and PRG in several monitoringwells. The MCL for iron is a secondary MCL and is not based onhealth end points but rather on aesthetic qualities. Thesecriteria are not promulgated. The maximum detected concentration,which was detected at sampling location MW-305S, is equivalent toa HI of 13 based on the EPA Region 9 PRG.

Lead was detected in MW-202, located in the upgradient portion ofthe Site, and MW-305S located in the downgradient portion. Leadwas not detected at any other sampling location during thissampling event.

Vanadium was only detected in MW-305S during this sampling event. The concentration detected at this sampling location is equivalentto an HI of 2. There is not a MCL or NJGWQS for Vanadium.

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It should be noted that the concentrations of Chromium, Iron andVanadium have increased since the original risk assessment, andare exceeding their respective risk-based criteria (PRG) and MCL.

The soil vapor intrusion exposure pathway which based on theconservative (health protective) assumption that buildings arelocated above the maximum detected concentration of thecontaminants of concern in the groundwater was not previouslyevaluated. The health-based screening criteria provided in theDraft Guidance for Evaluating the Vapor Intrusion to Indoor AirPathway from Groundwater and Soils (USEPA, 2002) was used toinitially evaluate this exposure pathway. This guidance providescalculations of concentrations in groundwater associated withindoor air concentrations at acceptable levels of cancer risk andnoncancer hazard. This review compared the maximum detectedconcentrations of the chemicals of potential concern with thevapor intrusion screening criteria (Table 2). The maximumdetected concentrations of the volatile chemicals detected duringthe 1999 groundwater sampling event did not exceed the vaporintrusion screening criteria. Based on the results of the 1999sampling event, vapor intrusion does not appear to be of issue atthe Site.

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Table 1 - Comparison of Maximum Detected Concentrations (ug/l)(1999) to the Region 9 Preliminary Remediation Goals (PRGs),National Primary Drinking Water Standards (MCLs) and the NJDEPGroundwater Criteria - Monitoring Wells

Chemicals ofPotential Concern

MaximumDetected

Concentration(ug/l)

Preliminary Remediation

Goals (PRGs) (ug/l)

NationalPrimaryDrinkingWater

Standards (MCL)(ug/l)

NJDEPGroundwaterStandards(ug/l)

Location

Cancer Risk=1x10-6HI = 1

Methylenechloride

0.002 4.3 (c) 30 304D

TBA(tert-butylalcohol)

0.024 303D

Chlorobenzene 0.016 110 (nc) 100 4 101R

1,4-Dichlorobenzene

0.003 0.5 (c) 75 75 101R

Dichlorofluoromethane

0.012 390 (nc) 304D

Naphthalene-d8 0.21 6.2 (nc) 101R

Anthracene-D10 0.041 1800 (nc) 2000 105R

Dimethyldiglucocarbonate

0.008 105R

Diethyltoluamide 0.012 303D

Propanic acid, 2-methyl-heptyl

0.004 303D

Acenaphthene 0.039 370 (nc) 400 304D

Perylene-d12 0.024 202

Arsenic* 13 0.045 (c) 10 8 305S

Lead* 73 15 10 202

Mercury 2 3.6 (nc) 2 2 304D

Aluminum* 8540 36000 (nc) 50 200 202

Barium 108 2600 (nc) 2000 2000 303D

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Cadmium* 7 18 (nc) 5 4 305S

Chromium* 860 110 (nc) 100 100 305S

Cobalt 16 730 (nc) 202

Copper 42 1500 (nc) 1300 1000 305S

Iron* 137000 11000 (nc) 300 300 305S

Manganese* 134 880 (nc) 50 50 101R

Nickel 19 730 (nc) 100 202

Vanadium* 78 36 (nc) 305S

Zinc 184 11000 (nc) 5000 5000 202

Sources:S Preliminary Remediation Goals (PRGs) are used for screening

purposes. Refer to http://www.epa.gov/Region9/waste/sfund/prg/files/02table.pdf

S Primary Drinking Water Standards (MCLs) are legallyenforceable standards. Refer to: http://www.epa.gov/safewater/mcl.html#inorganic

Footnotes:S nc –> non-cancer endpointS c –> cancer endpointS * –> the contaminant of concern has exceeded the cancer

risk range or the non-cancer hazard threshold and/or itsrespective MCL.

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Table 2 - Comparison of the Maximum Detected Concentration of theVolatile Chemicals Detected in the Groundwater during the 1999Sampling Event with Vapor Intrusion Screening Criteria

Chemicals of PotentialConcern

MaximumDetected

Concentration

(ug/l)

Vapor IntrusionScreening Value

(ug/l)

Vapor IntrusionScreening Value

(ug/l)

Cancer Risk=1*10-6

Non-cancer hazard=1Cancer Risk = 1*10-4

Non-cancer hazard=0.1

Methylene chloride 0.002 58 (c) 0.58 (c)

TBA(tert-butylalcohol)

0.024

Chlorobenzene 0.016 390 (nc) 39 (nc)

1,4-Dichlorobenzene 0.003 8200 (nc) 820 (nc)

Dichlorofluoromethane 0.012 14 (nc) 1.4 (nc)

Naphthalene-d8 0.21 150 (nc) 15 (nc)

Anthracene-D10 0.041

Dimethyldiglucocarbonate

0.008

Diethyltoluamide 0.012

Propanic acid, 2-methyl-heptyl

0.004

Acenaphthene 0.039

Perylene-d12 0.024

Sources:1 - Vapor Intrusion Screening Values are used for screeningpurposes. Refer to: http://www/epa.gov/correctiveaction/eis/vapor.htm

Footnotes:S nc –> non-cancer endpointS c –> cancer endpoint

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Question C: Has any other information come to light that could callinto question the protectiveness of the remedy?

According to the 1996 Closure and Post-Closure Plan, groundwatersampling is to be conducted annually. This has not been done. Thelast round of groundwater samples was collected six years ago. Itis recommended that sampling of the monitoring wells be conductedannually and analyzed for the parameters listed in the JCO for thenext five years. Remedy Assessment Summary

- The soil and washed gravel cap appears effective;

- The fence around the Site is generally in good condition;

S Groundwater monitoring wells were last sampled in 1999 andEPA is recommending that groundwater be sampled annuallyfor the next five years;

S The methane gas sampling and monitoring program is active;and

S There is no significant evidence of trespassing, vandalismor damage at the Site.

This Site has ongoing operation and maintenance activities conductedby Jackson Township.

VIII. Issues, Recommendations and Follow-Up Actions

As a result of this review, EPA has determined that although NJDEPhas been providing oversight of this Site, the last round ofgroundwater data collected was in September 1999. Therefore, thereis not sufficient groundwater data available to accurately assessthe presence of constituents in groundwater at this time. In orderto characterize the current nature and extent of the contaminationassociated with the Site, the Township, pursuant to the JCO and withNJDEP oversight, should conduct the following activities:

S perform a well assessment to determine which wells still existand which are serviceable. It is possible that new wells willhave to be installed. The June 1995 Landfill Closure Planspecifies that the wells 105R, 202, 214,and WD-1 are to bemonitored however, the integrity of these wells will have to beassessed by the Township prior to implementing the groundwatersampling and monitoring plan;

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S conduct an annual groundwater monitoring program including allavailable wells and analyze for Target Compound List (TCL)volatiles and semi-volatiles, Target Analyte List (TAL) metals,sulfate, chlorides and water level (pursuant to the JCO); and

S properly dispose of the barrels of Investigation-Derived Wasteremaining from the installation of the methane flaring wells.

In addition, the methane gas monitoring program should also continueto monitor and assess the methane gas migration from the landfill,under NJDEP oversight. The Township should continue to manage theoperation and maintenance program for the landfill, including thequarterly Site inspections, routine cap maintenance and fenceinspection.

IX. Protectiveness Statement

The selected remedy, ‘No Further Action with Maintenance andMonitoring’ protects human health and the environment in the shortterm. However, in order for the remedy to be protective in the longterm, additional groundwater monitoring is required. There are noexposure pathways that could result in unacceptable risks and noneexpected as long as the New Jersey Department of EnvironmentalProtection properly enforces its State authorities, and JacksonTownship properly maintains and monitors the landfill. In order toassure that the remedy is protective in the long term, additionalgroundwater monitoring will need to be performed and the dataevaluated.

X. Next Review

The selected remedy requires a five-year review to assure completecompliance with CERCLA and the JCO. The five-year review processwill require documentation to confirm that the groundwater and airmonitoring programs are in place and that the remedy providesadequate protection of human health and the environment. EPA willconduct another Five-Year review by September 2010.

Approved:

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Figure 1 - Site Map

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APPENDIX A

List of Documents Reviewed

S Revised Closure Plan Approval-Minor Modification, Methane GasVenting System, dated September 16, 2004; by NJDEP

S Monthly Landfill Gas Survey Results, December 27, 2004,prepared by JCA Associates

S Record of Decision, EPA, September 27, 1994

S Groundwater Monitoring Data, January 2000

S Five-Year Review Report, September 1999

S Remedial Investigation Data

S Site Maps

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APPENDIX B

List of Acronyms

ARAR Applicable or Relevant and Appropriate Requirement

CERCLA Comprehensive Environmental Response, Compensation, andLiability Act

CFR Code of Federal Regulations

EPA United States Environmental Protection Agency

JCO Judicial Consent Order

MCLs Maximum Contaminant Levels

NJDEP New Jersey Department of Environmental Protection

NCP National Oil and Hazardous Substances PollutionContingency Plan

NPL National Priorities List

O&M Operation and Maintenance

PQL Practical Quantitation Levels

PRGs Preliminary Remediation Goals

RA Remedial Action

RAO Remedial Action Objective

RCRA Resource Conservation and Recovery Act

RD Remedial Design

RI/FS Remedial Investigation/Feasibility Study

ROD Record of Decision

SARA Superfund Amendments & Reauthorization Act

VOC Volatile Organic Compound