SDMS Document

SUPERFUND RECORD OF DECISION

90569

LANDFILL & DEVELOPMENT COMPANY SITE

EASTAMPTON, MOUNT HOLLY, AND LUMBERTON TOWNSHIPS

BURLINGTON COUNTY NEW JERSEY

Prepared by: N.J. Department of Environmental Protection Site Remediation and Waste Management Program Bureau of Case Management September 2004

DECLARATION FOR THE RECORD OF DECISION

SITE NAME AND LOCATION

Landfill and Development Company Superfund Site Mount Holly, Eastampton, and Lumberton, Burlington County, New Jersey

STATEMENT OF BASIS AND PURPOSE

This Record of Decision (ROD) documents the selection by the New Jersey Department of Environmental Protection (NJDEP) of the remedial action for the Landfill and Development Company site (the Site) in accordance with the requirements of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended (CERCLA), 42 U.S.C. §9601 et seq. and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 Code of Federal Regulations (CFR) Part 300. An administrative record for the Site, established pursuant to the NCP, 40 CFR §300.800, contains the documents that are the basis for NJDEP's selection of the remedial action (see Appendix I).

The United States Environmental Protection Agency (EPA) has been consulted on the planned remedial action in accordance with CERCLA §121(f), 42 U.S.C. §9621(f), and it concurs with the selected remedy (see Appendix In. ASSESSMENT OF THE SITE

The response action selected in this ROD is necessary to protect public health or welfare or the environment from actual or threatened releases ofhazardous substances from the Site into the environment.

DESCRIPTION OF THE SELECTED REMEDY

The Selected Remedy represents the comprehensive remedial action for the Site. It addresses ground water contamination and site security. Ground water will be remediated to the Ground Water Quality Standards through active remediation of the landfill contents in Cell 9 of the landfill.

The major components of the Selected Remedy include:

• Construction and operation of a ground water extraction system in the Middle Wenonah aquifer in the Central Area to provide hydraulic containment,

• Construction and operation of Enhanced Aerobic Treatment (Cell 9), whereby leachate and ground water would be re-circulated into the landfill along with appropriate air injection to enhance contaminant degradation. Excess water would be discharged to the POTW for treatment if necessary,

• Long-term monitoring for ground water exceeding the remedation goals, including in the Flank Areas not targeted for active extraction and treatment,

• Continued maintenance of the existing final cover system on the landfill,

• Continued landfill leachate and'gas monitoring, collection, and disposal,

• Decommissioning of residential water-supply wells downgradient of the landfill, and,

• Continued maintenance of the site security.

Burlington County is in the process of acquiring properties along Rabbit Run and Hand Lane. The County would like to acquire these properties for various reasons, including:

• The dwellings are served by on-site septic systems located in the floodplain or adjacent to Rancocas Creek. These septic systems may be responsible for the exceedance of the water quality standard for fecal coliform in the North Branch of the Rancocas Creek,

• The dwellings are in the floodplain and therefore are subject to frequent flooding, and,

• These properties lie adjacent to Smithville Park, and the County would like to create a greenway along the North Branch of the Rancocas Creek that would link Smithville Park to other County-owned properties along the Creek and Rancocas State Park.

If the County does not provide written documentation to NJDEP from the Board of Chosen Freeholders of Burlington County within 6 months that the properties will be acquired by March 2006, or otherwise satisfactorily demonstrate to NJDEP that it will acquire these properties in a reasonable timeframe, the following remedy will also be implemented:

• Water line extension to Hand Lane and along the western portion ofRabbit Run, downgradient of the landfill.

If the County does provide written documentation to NJDEP that it will acquire these properties in a reasonable timeframe, then the water line extension along the western portion of Rabbit Run, down gradient of the landfill, will not be installed.

Currently the residents on Hand Lane and Rabbit Run are provided bottled water by the L&D Company. Those residents will continue to receive bottled water until their property either is acquired by the County or the water line is installed.

DECLARATION OF STATUTORY DETERMINATIONS

Part 1: Statutory Requirements The Selected Remedy is protective of human health and the environment, complies with Federal and State requirements that are applicable or relevant and

appropriate to the remedial action (unless justified by a waiver), is cost-effective, and utilizes pennanent solutions and alternative treatment (or resource recovery) technologies to the maximum extent practicable.

Part 2: Statutory Preference for Treatment This remedy also satisfies the statutory preference for treatment as a principal element of the remedy (Le., reduces the toxicity, mobility, or volume ofhazardous substances, pollutants, or contaminants as a principal element through treatment).

Part 3: Five-Year Review Requirements Because this remedy will result in hazardous substances, pollutants, or contaminants remaining on-site above levels that allow for unlimited use and unrestricted exposure, a statutory review will be conducted within five years after initiation of remedial action to ensure that the remedy is, or will be, protective ofhuman health and the environment.

SEP 3 () 2004

Date

TABLE OF CONTENTS

PAGE

SITE NAME, LOCATION AND DESCRIPTION 1

SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES ·17

FIGURES

TABLES

APPENDIX I ADMINISTRATIVE RECORD INDEX

SITE HISTORY AND ENFORCEMENT ACTIVITIES 1

HIGHLIGHTS OF COMMUNITY PARTICIPATION 3

SCOPE AND ROLE OF ACTION 3

SUMMARY OF SITE CHARACTERISTICS 4

CURRENT AND POTENTIAL FUTURE SITE AND RESOURCE USES 6

SUMMARY OF SITE RISKS 6

REMEDIAL ACTION OBJECTIVES 12

DESCRIPTION OF REMEDIAL ALTERNATIVES 13

PRINCIPAL THREAT WASTES 21

SELECTED REMEDY 21

STATUTORY DETERMINATIONS 24

DOCUMENTATION OF SIGNIFICANT CHANGES 25

•APPENDIX II EPA LETTER OF CONCURRENCE APPENDIX III RESPONSIVENESS SUMMARY

SITE NAME, LOCATION, AND DESCRIPTION

The Landfill & Development Company Site (the Site), which is a closed landfill, is located in Burlington County, New Jersey. The Site occupies portions of the Townships ofMount Holly, Eastampton, and Lumberton including the following: portions of Lots 1 and 18, Block 1401 in Eastampton Township; portions of Lots 1 and 2, Block 23 in Lumberton Township; and portions of Lots 10, 11, 12, 15.02 and 16, Block 118 in Mount Holly Township. The Site is located on the north side of Route 38, approximately one mile west ofRoute 206 and is approximately 200 acres in size. The location of the landfill is depicted in Figure 1. The closed landfill consists of two sections, the Mount Holly section on the west and the Eastampton section on the east. In addition to the two landfill sections, the Site includes five sedimentation ponds, a perimeter road. a leachate collection system, a landfill gas management system, and a closed power plant. The property is surrounded by a chain-link fence with locking gates. The North Branch ofRancocas Creek (hereafter referred to as Rancocas Creek) is located approximately 700 feet north of the landfill boundary.

The landfill overlies the Cape May/Mount Laurel Sands, Middle Wenonah, and Englishtown Aquifers. The New Jersey Department ofEnvironmental Protection (NJDEP) has designated these aquifers in the vicinity of the Site as Ground Water Class ITA.

SITE mSTORY AND ENFORCEMENT ACTIVITIES

Site History

The Site operated as a sand and gravel pit from the early 1940's until approximately 1968. The first waste disposal activities at the Site are believed to have been initiated in 1962, when George Pettinos began disposing of demolition debris in the Mount Holly section of the landfill. The disposal of demolition debris was conducted from 1962 until the late 1960's. During this period of time a 10-foot thick layer ofrefuse was deposited on what is believed to have been the excavated base of the sand and gravel pit. In 1968, George Pettinos leased the Mount Holly section to Mount Holly Township for use as a landfill, and the landfill began accepting industrial and commercial solid waste and sewage sludge. The Landfill and Development Company (L&D Company) acquired the Site in 1971, and initiated landfilling operations in the Eastampton section of the Site in 1976. These operations were conducted until 1981. L&D Company operated the landfill until December 31. 1986 when it ceased accepting waste materials after reaching its permitted capacity. The landfill sections were closed in accordance with an approved closure plan, . and the constructed closure systems for the entire landfill were approved by NJDEP on May 24. 1995. The engineering controls that are maintained as part of the landfill post-closure requirements include:

• A leachate collection system in the Mount Holly section and in a limited area of the Eastampton section

• A methane gas collection system

• A clay cover system.

Enforcement History and Previous Investigations

On May 15, 1976, pursuant to NJ.S.A. 13:1E-l et seq., the NJDEP issued L&D Company an Amended Registration and Stipulation for the operation of a sanitary landfill at the Site. On September 13, 1982 the NJDEP issued L&D a second Amended Certificate ofApproved Registration and Engineering Design Approval. The conditions set forth in paragraphs 3 and 5 of the Certificate required that a comprehensive ground water investigation be conducted at the Site to determine the nature and extent of contamination at the Site and required that a study be undertaken to determine how best to abate or prevent such contamination. L&D sought administrative and judicial review of certain provisions of the Amended Certificate that resulted in the issuance ofa Second Amended Certificate of Registration and Engineering Design Approval dated May 2, 1984. In 1983, the Site was placed on the National Priorities List (NPL) by EPA based on initial ground water investigations. On June 28, 1985 the NJDEP issued L&D a final NJPDES Permit 0033502. The permit required L&D to perform a ground water study and remedy assessment for the Site. The data generated was to be used by the NJDEP to determine if there was any potential or actual threat to the public health or safety or damage to the environment. In February 1986 L&D Company's consultant prepared a report entitled "Hydrogeologic Investigation and Assessment, L&D Landfill, Mt. Holly, New Jersey." This report included analytical data from ground water monitoring well sampling conducted in February 1985 at or near the Site under theNJPDES permit. The wells that were sampled demonstrated ground water contamination in the immediate vicinity of the landfill.

On May 30, 1986, pursuant to the Spill Compensation and Control Act, N.J.S.A. 58:10-23.1lf, the NJDEP directed L&D Company to remove or arrange for the removal of such hazardous substances in the ground water by providing the NJDEP funds to conduct a remedial investigation and feasibility study. On September 30, 1986 the NJDEP awarded a contract to the firm ofBakerrrSA, Inc. to perform a remedial investigation and feasibility study. On July 21, 1988 BakerITSA, Inc. submitted a report that presented data showing that hazardous substances were discharged into the ground water.

In 1988, the L&D Company entered into an Administrative Consent Order (ACO) to fund a Remedial InvestigationlFeasibility Study (RIlFS). A Phase I RI Report was issued in July 1988. The L&D Company and NJDEP entered into a second ACO in July 1990 to complete a Phase II RIIFS. The Phase IT RIlFS consisted of three volumes: (1) Remedial Investigation, January 1994; (2) Feasibility Study, September 1993; and (3) Risk Assessment, August 1993. A series of agency comments precipitated additional field work, described in the Phase II RI Addendum, September 1995.

Beginning in June 1997, the L&D Company, in consultation with NJDEP and EPA, updated and augmented previous Site reports. This work was performed by GeoTrans, Inc. (previously known as "HSI GeoTrans"). The resulting documents were:

• Updated Well Survey Report (HSI GeoTrans, December 29, 1999)

2

• Revised Ground Water Remedial Investigation and ORC Pilot Test Report (HSI GeoTrans, June 12,2000) (referred to as the RI Report)

• • Revised Ecological Risk Assessment Report (HSI GeoTrans, April 18, 2000, plus Addendum dated December 15,2000)

• Revised Human Health Risk Assessment (GeoTrans, May 16,2001)

• Revised Feasibility Study Report (GeoTrans, August 8, 2001) (referred to as the FS Report)

HIGHLIGHTS OF COMMUNITY PARTICIPATION

The documents referenced above have been placed in the repository. The Proposed Plan, along with notice of the availability of the RIlFS, was released to the public on May 20,2004. The documents and the plan were made available to the public in both the Administrative Record and at information repositories maintained at the Burlington County Library and at NJDEP's Trenton office.

The notice of availability was published in the Burlington County Times on May 17,2004 and the Courier Post on May 20, 2004. A public comment period was originally scheduled from May 20 through June 21,2004, however it was extended until July 21,2004 at the request of the public. A public meeting was held in Westampton, New Jersey on May 24,2004. At this meeting, representatives from NJDEP, USEPA, the L&D Company and GeoTrans, Inc. answered questions about the Site and the remedial alternatives under consideration. In addition, a meeting was held with the Rancocas Creek Association on July 15,2004 with NJDEP representatives.

Based on the comments received at the May 24, 2004 meeting, the July 15, 2004 meeting, and during the public comment period, the local community and public officials generally supported the agencies' preferred alternative presented in the Proposed Plan. Public comment focused on the water line extension as well as specific issues related to the remedy. Detailed responses to these comments are contained in the Responsiveness Summary.

SCOPE AND ROLE OF ACTION

NJDEP has addressed much of the Site under the closure and post-closure provisions of the New Jersey Solid Waste Regulations, N.J.A.C. 7:26-2A.9, through the construction of closure systems for the entire landfill, approved by NJDEP in 1995. The engineering controls on the landfill are maintained as part of the landfill's post-closure requirements. The scope and role of this action addresses the only outstanding issue for this Site, the ground water that is contaminated from the landfill. The remedy selected in this ROD represents a long-term comprehensive remedy to address on-site and off-site ground water contamination. The primary objective of the selected remedy is to reduce contaminant levels in affected media, specifically ground water, to levels that are protective of human health and the environment. This is the final remedy for the Site.

3

SUMMARY OF SITE CHARACTERISTICS

Site Hydrology

Surface water features in the vicinity of the Site are illustrated on Figure 1. The Rancocas Creek is located north of the landfill and flows in a westerly direction. A man-made canal, known locally as the Smithville Canal, originates at Smithville Lake, and flows (when not stagnant or dry) to the west/northwest. Surface drainage at the landfill is controlled by the topography and a surface water runoffcollection system that includes five sedimentation ponds. There are some locations between the landfill and Rancocas Creek where ground water seasonally discharges to land surface (referred to as "ground water seeps"). These features should not be confused with seeps ofliquid leaching from the landfill itself, or "leachate seeps", which are not present. During wet periods numerous ground water seeps have been observed between the landfill and Rancocas Creek, some with standing water and others flowing. However, during dry periods the ground water seeps have been observed to be dry.

Site Geology/Hydrogeology

The L&D Site is divided into five hydrogeologic units based on similar hydrologic properties. The units, in descending order from the ground surface, are as follows:

• Mount Laurel/Cape May Sand (MLCMS) aquifer • Upper Wenonah confining unit • Middle Wenonah aquifer • MarshalltownlLower Wenonah confining unit • Englishtown aquifer

Ground water flow in all three aquifers is northward, towards Rancocas Creek (see Figures 2 to 4). The Middle Wenonah and MLCMS aquifers discharge into Rancocas Creek. At times, the MLCMS aquifer north of the Eastampton section of the landfill may also discharge into Smithville Canal. Ground water also discharges seasonally as ground water seeps. Vertical hydraulic gradients are downward to the Englishtown aquifer south of the landfill, and upward from the Englishtown aquifer north of the landfill (with an increasing upward gradient towards Rancocas Creek).

Based on a comparison ofhistorical ground water levels versus the bottom elevation of landfill contents, ground water is likely in contact with the refuse in the northwestern portion of the Mount Holly section. There are several other areas with the potential for ground water to periodically be in contact with the refuse.

4

Ground Water Impacts

Based on the Rl Report, portions of the MLCMS aquifer and Middle Wenonah aquifer have been impacted by the landfill. However, ground water in the underlying Englishto-wn aquifer has not been impacted by the landfill.

The greatest impacts to ground water are found in the Middle Wenonah aquifer in a relatively narrow band down gradient of the eastern portion of the Mount Holly section, including wells 22M, LDM-21O, and LDM-206. This relatively narrow band ofhigher concentrations is referred to as the "Central Area", and the areas ofmuch lower ground water concentrations on either side of the Central Area are referred to as the "Flank Areas" (See Figure 7). Concentrations of volatile organic compounds (VOCs) in the MLCMS and Middle Wenonah aquifers, based on the sampling performed in 1999, are presented on Figures 5 and 6, respectively.

Based on VOC concentrations, the width of the Central Area is approximately 800 feet, and the width of the core zone of the Central Area (including wells 22M, LDM-21O, and LDM-206) may be considerably less than 800 feet. As illustrated on Figure 6, concentrations of these VOCs generally do not exceed ground water criteria in Flank Area wells. Based on the sampling results for VOCs (see Figures 5 and 6), the Central Area is only associated with the Middle Wenonah aquifer, and not the MLCMS aquifer.

The following VOCs have concentrations that exceed ground water criteria in the Central Area:

Parameter NJGWQS (ug/I)

1-2,dichloroethane 2 2-butanone (MEK) 300 4-methyl-2-pentanone (MIBK) 400 acetone 700 benzene )

cis-l,2-dichloroethene 10 methylene chloride 2 toluene 1000 vinyl chloride 5

Notes: NJGWQS: New Jersey Ground Water Quality Standard MCL: Federal Maximum Contaminant Level

MCL(ug/l) Maximum Concentration in Central Area (ug/l)

5 1800 J 6400 2800 3900D

5 ]40 D 70 77D 5 2100

1000 1700 2 28 J

J: Value estimated by laboratory D: Based on a sample diluted in the laboratory

Elevated metals concentrations are found in ground water at background wells, and in some cases background ground water quality exceeds ground water quality criteria (e.g., aluminum, arsenic, cadmium, chromium, iron, lead, manganese, and thallium), for total andlor dissolved metals. However, sampling results indicate (as explained in detail in the RI Report) that for some inorganic parameters (including metals) the landfill is causing impacts to ground water quality, while for other inorganic parameters it is difficult to determine if the landfill is causing impacts to ground water. Inorganic parameters impacted by the landfill at one or more wells include chloride, hardness, ammonia, TDS, iron, lead, manganese, and sodium. Inorganic parameters

5

that mayor may not be impacted by the landfill include aluminum, arsenic, cadmium, and thallium.

CURRENT AND POTENTIAL FUTURE SITE AND RESOURCE USES

Site uses: The Site is currently a closed landfill which is surrounded by a chain-link fence with locking gates. At this point in time, there are no plans for future use of the property other than to maintain the landfill. There have been inquiries from the surrounding community whether the property could be used for recreational open space (e.g., ballfields), but such a determination would not be made until after the effectiveness of the reinjection system has been monitored. In the event that the property is proposed for recreational use, L&D Company would need to ensure that it would be in compliance with the closure plan for the landfill.

Ground water uses: The recent well survey identified 18 existing wells hydraulically down gradient of the landfill. Of the 18 wells, only two are reportedly used for drinking water. These wells, both located on Wollner Drive, are completed in the Englishtown aquifer, which has not been impacted by the Site contamination. The remaining 16 wells are reportedly used for agriculture or general household (non-potable) purposes. Other than the properties with Englishtown aquifer wells on WoHner Drive, all areas down gradient of landfill have access to public water except homes along Rabbit Run and Hand Lane, where the residents are currently supplied with bottled drinking water and where a water line extension is currently planned if Burlington County does not acquire those properties.

SUMMARY OF SITE RISKS

Baseline human health and ecological risk assessments were conducted to evaluate the potential for current and future impacts of site-related contaminants on receptors visiting, utilizing or inhabiting the Site. Under baseline conditions, there are certain exposure scenarios which present unacceptable human health risk.

Human Health Risk Assessment

As part of the RIlFS for the site, a Human Health Risk Assessment (HHRA) was conducted to estimate the potential current and future effects of site contaminants on human health. The HHRA estimates the human health risk which could result from the contamination at the site if no remedial action were taken, and without institutional controls.

A four-step process is utilized for assessing the site-related human health risks for a reasonable maximum exposure scenario: Hazard Identification - identifies the chemicals of potential concern (COPCs) at the site based on several factors such as toxicity, frequency of detection, and concentration; Exposure Assessment - estimates the magnitude of actual andlor potential human exposure, the frequency and duration ofthese exposures, and the pathways (e.g., ingesting contaminated soil) by which humans are potentially exposed; Toxicity Assessment - determines the types of adverse health effects associated with chemical exposures, and the relationship between magnitude of exposure (dose) and severity of adverse effects (response); Risk

6

Characterization - summarizes and combines outputs of the exposure and toxicity assessments to provide a quantitative assessment of site-related risks.

The current and future use of the site property is as a landfill in the risk assessment. The current and likely future uses of the neighboring properties are commercial/light industrial, and residential. The HHRA focuses on exposure to contaminants in on-site sedimentation ponds, in the ground water down-gradient of the site, and in surface water bodies which receive ground water discharges.

Hazard Identification

In this step, chemicals ofpotential concern (COPCs) were identified based on historical detection at the site, frequency of detection, potential toxicity, carcinogenic potential and classification, and a concentration-toxicity screen. This process, which is consistent with current EPA guidance for conducting human health risk assessments, is thoroughly described in Section 4 of the Revised Human Health Risk Assessment report.

Samples were collected from all media suspected to be impacted by the site, specifically ground water (MLCMS aquifer and the Central Area and the Eastern and Western Flank Areas of the Middle Wenonah aquifer), ground water seeps, surface water and sediment from Rancocas Creek, Smithville Canal and four sedimentation ponds (northeast, northcentral, southeast, and southcentral sedimentation ponds). COPCs were identified through a process that included screening against appropriate risk-based concentrations and consideration of frequency of detection.

As only the Central Area of the Middle Wenonah aquifer is associated with unacceptable levels of risk, this summary of the risk assessment will focus on that area. Chemicals that were retained as COPCs in the Central Area of the Middle Wenonah aquifer include arsenic, 1,2­dichloroethane, 2-butanone, 4-methyl-2-pentanone, acetone, benzene, methylene chloride, toluene, and vinyl chloride.

Exposure Assessment

Based on the current and likely future use of the site, potential human receptor scenarios evaluated in the HHRA are recreational exposure through incidental ingestion ofand dermal contact with surface water and sediment in Rancocas Creek, Smithville Canal, the four sedimentation ponds and the ground water seeps, and ingestion of fish harvested from Rancocas Creek. Also, potential exposure to ground water was assessed in a residential scenario under the assumption that ground water would be used as a potable water supply. The evaluation of this medium considered exposure through ingestion of and dermal contact with ground water and inhalation ofvolatiles from ground water. A complete discussion of the Exposure Assessment, including all exposure assumptions used for the scenarios identified, can be found in Section 5 of the Revised Human Health Risk Assessment Report.

7

Vsing this information, the "reasonable maximum exposure" scenario, which identifies the highest level of human exposure that could reasonably be expected to occur, was evaluated.

An exposure point concentration (EPC) was developed for each contaminant in the media. Data were evaluated to determine whether they were normally or lognormally distributed. In accordance with EPA guidance, the EPC was the 95 percent upper confidence limit (95% VCL) of the arithmetic mean of the log-transformed data. For those chemicals where the maximum detected concentration was less than the 95% VCL, or where the paucity of the data set would preclude calculation of a 95% VCL, the maximum detected concentration was used as the EPC. EPC values for each contaminant and each media can be found in the RI report. EPCs for those chemicals associated with unacceptable levels of risk in the Central Area of the Middle Wenonah aquifer can be found in Table 1.

Toxicity Assessment

The toxicity assessment determines the types of adverse health effects associated with chemical exposures, and the relationship between the dose of a chemical and the response elicited. Two distinct types ofhealth effects are considered, carcinogenic effects, and noncarcinogenic, or systemic effects. A comprehensive presentation of the toxicity assessment can be found in Section 6 of the Revised Human Health Risk Assessment Report.

Toxicity data for the HHRA were provided by the Integrated Risk Information System (IRIS) database, the Health Effects Assessment Summary Tables (HEAST), and the National Center for Environmental Assessment (NCEA). This information is presented in Tables 6-1 through 6-4 of the RI Report.

Toxicity information for the chemicals of concern in the Central Area of the Middle Wenonah aquifer can be found in Tables 2 (carcinogenic toxicity data) and 3 (noncarcinogenic toxicity data).

Risk Characterization

The baseline risk assessment estimates the potential risk and hazards to human health if no remedial action occurs. A more detailed discussion of the cumulative risks and hazards associated with the Landfill and Development Site can be found in Section 7 of the Revised Human Health Risk Assessment Report.

For carcinogens, risks are generally expressed as the incremental probability of an individual developing cancer over a lifetime as a result ofexposure to a carcinogen. Excess lifetime cancer risk is calculated from the following equation:

Risk = LADDxSF

where: Risk = a unitless probability (1 x 10-4) of an individual developing cancer

8

LADD= lifetime average daily dose averaged over 70 years (mg!k.g-day) SF = slope factor, expressed as (mg!kg-dayr1

These risks are probabilities that usually are expressed in scientific notation (such as 1 x 10-4). An excess lifetime cancer risk of 1 x 10-4 indicates that one additional incidence ofcancer may occur in a population of 10,000 people who are exposed under the conditions identified in the assessment. As stated in the National Contingency Plan, EPA's acceptable risk range for site­related exposures is 10-4 to 10-6. The State ofNew Jersey has an acceptable risk level of 1 x 10-6

•

The potential for noncarcinogenic effects is evaluated by comparing an exposure level over a specified time period, such as a 30-year period of exposure, with a reference dose (RID) derived for a similar exposure period. An RID represents a level that an individual may be exposed to that is not expected to cause any deleterious health effect. The ratio of the exposure dose to the reference dose is called a hazard quotient (HQ). An HQ of less than or equal to 1 indicates that the exposure dose is less than or equal to the reference dose, and that noncarcinogenic health effects are unlikely to occur. The hazard index (HI) for an exposure pathway is generated by summing the HQs for all chemicals ofconcern for a singular pathway. An HI of less than or equal to 1 indicates that noncarcinogenic health effects are unlikely to occur. An HI of greater than 1 indicates the likelihood that site-related exposures may result in noncarcinogenic health effects.

The HQ is calculated as follows:

HQ = ADDIRID

where: HQ = hazard quotient ADD = average daily dose (mg/kg-day) RID = reference dose (mglkg-day)

The ADD and the RID will represent the same exposure period (i.e., chronic, subchronic, or acute).

As shown in Table 4, the cumulative carcinogenic risk from exposure to ground water in the Central Area of the Middle Wenonah aquifer is 1.7 x 10-2 for the adult! child resident. For this population, the following chemicals ha,ve been identified as risk drivers; that is, the risk from exposure through all evaluated pathways exceeds the upperbound of EPA's acceptable level of 1 x 10-4: arsenic, 1,2-dichloroethane, benzene, methylene chloride, and vinyl chloride. It should be noted that the other COPCs do contribute to the cumulative risk, but not at a level greater than 1 x 10-4. All carcinogenic risks from exposure to the other media that have been investigated are within EPA's acceptable levels ofcarcinogenic risk.

Presented in Table 5, the noncarcinogenic hazard index from exposure to contaminants in the Central Area of the Middle Wenonah aquifer through ingestion, inhalation, and dermal contact is

9

230 for the adult/child resident. The risk drivers for this population are: arsenic, 1,2­dichloroethane, 2-butanone,4-methyl-2-pentanone, acetone, benzene, methylene chloride, toluene, and vinyl chloride. Therefore, the HQ for each of these chemicals exceeds the EPA benchmark of an HQ of 1. It should be noted that the other COPCs do contribute to the cumulative hazard, but not at a level which exceeds EPA's acceptable HQ of 1. HI values estimated for exposure to other media that have been investigated are below the acceptable HI of 1.

A complete list of the cancer risks and noncancer HI values for all contaminants of potential concern in all media can be found in Tables 7-1 through 7-37 in the Revised Human Health Risk Assessment Report.

Based on these risk estimates driven by the presence of arsenic, l,2-dichloroethane, 2-butanone, 4-methyl-2-pentanone, acetone, benzene, methylene chloride, toluene, and vinyl chloride in the ground water of the Central Area of the Middle Wenonah aquifer, the response action selected in this ROD is necessary to protect public health or welfare of the environment from actual or threatened releases ofhazardous substances into the environment.

Discussion of Uncertainties

The procedures and inputs used to assess risks in this evaluation, as in all such assessments, are subject to a wide variety of uncertainties. In general, the main sources of uncertainty include:

1. environmental chemistry sampling and analysis 2. environmental parameter measurement 3. fate and transport modeling 4. exposure parameter estimation 5. toxicological data.

Uncertainty in environmental sampling arises in part from the potentially uneven distribution of chemicals in the media sampled. Consequently, there is significant uncertainty as to the actual levels present. Environmental chemistry-analysis error can stem from several sources including the errors inherent in the analytical methods and characteristics of the matrix being sampled. Uncertainties in the exposure assessment are related to estimates of how often an individual would actually come in contact with the chemicals of concern, the period of time over which such exposure would occur, and in the models used to estimate the concentrations of the chemicals of concern at the point of exposure.

Uncertainties in toxicological data occur in extrapolating both from animals to humans and from high to low doses of exposure, as well as from the difficulties in assessing the toxicity of a mixture of chemicals. These uncertainties are addressed by making conservative assumptions concerning risk and exposure parameters throughout the assessment. As a result, the risk assessment provides upper-bound estimates of the risks to populations near the site, and is highly unlikely to underestimate actual risks related to the site.

10

Summary of Human Health Risks

The New Jersey Brownfield and Contaminated Site Remediation Act, N.J.S.A. 58:lOB-l, et. seg., has set the acceptable cancer risk for human carcinogens at 1 x 10-6 (one-in-one-million) and acceptable non-carcinogenic risk for any given effect to a value not to exceed an HI of 1.0. These established acceptable risk values are for any particular contaminant and not for the cumulative effects of more than one contaminant at a Site.

Significant risks to human health are indicated for ground water in the Central Area of the Middle Wenonah aquifer. In the Flank Areas of the Middle Wenonah aquifer, potential risks to human health were calculated, but were generally associated with a small number of measurements for total arsenic that appear to be naturally occurring and, therefore, not a result of the landfill. This is also the case with the potential risks associated with ground water in the MLCMS aquifer, ground water seeps, Rancocas Creek, Smithville Canal, and the sedimentation ponds.

Ecological Risk Assessment (ERA)

A four-step process is utilized for assessing site-related ecological risks for a reasonable maximum exposure scenario: Problem Formulation - a qualitative evaluation of contaminant release, migration, and fate; identification of contaminants of concern, receptors, exposure pathways, and known ecological effects of the contaminants; and selection of endpoints for further study. Exposure Assessment - a quantitative evaluation of contaminant release, migration, and fate; characterization ofexposure pathways and receptors; and measurement or estimation of exposure point concentrations. Ecological Effects Assessment - literature reviews, field studies, and toxicity tests, linking contaminant concentrations to effects on ecological receptors. Risk Characterization - measurement or estimation of both current and future adverse effects.

Primary assessment endpoints evaluated in the ecological risk assessment were:

• Survival, growth, and reproduction of benthic communities in Rancocas Creek and Smithville Canal.

• Survival, growth, and reproduction offish communities in Rancocas Creek and Smithville Canal.

• Survival, growth, and reproduction of avian piscivores (Le., birds that eat fish) foraging in Rancocas Creek and Smithville Canal.

Surface water and sediment concentrations in the ponds/outfalls and ground water seeps were also compared to appropriate criteria/standards and background results.

Sediment and surface water data, supplemented by exposure modeling for avian piscivores, were utilized to evaluate ecological effects to the assessment endpoints. Sediment monitoring data were used to evaluate exposures to benthics, while surface water monitoring data were used to

11

evaluate exposures to fish. Surface water monitoring data and bioaccumulation models were used to estimate dietary intakes to avian piscivores. Available toxicity criteria, standards, and toxicity data from the literature were utilized to characterize ecological effects. Potential ecological risks to the assessment endpoints were characterized by integrating the results of the exposure assessment with the toxicity data. Concentrations measured adjacent to the landfill were compared with concentrations measured at background locations (and in some cases, concentrations in ground water), to evaluate if the landfill is causing or contributing significantly to ecological risk.

The quantitative ecological risk assessment indicated potential risk to some ecological receptors (e.g., potential impacts to avian piscivores from selenium in surface water and potential impacts to benthics from silver in sediments). However, the data strongly suggest that the L&D landfill is not causing or adding to any ecological risks. The stressors to ecology of the Site vicinity are most likely: 1) naturally occurring high levels of heavy metals; and 2) anthropogenic activities not associated with the landfill (i.e., residential development and activity) that would lead to increased non-point source loadings into surface water bodies.

REMEDIAL ACTION OBJECTIVES

Remedial action objectives (RAOs) are specific goals to protect human health and the environment. These objectives are based on available information and standards, such as applicable or relevant and appropriate requirements (ARARs), NJDEP's Ground Water Quality Standards (GWQS), and the Federal Maximum Contaminant Levels (MCLs). The RAOs are intended to mitigate the health threat posed by the ingestion of ground water and direct contact with landfill contents.

The Feasibility Study (FS) evaluated remedial alternatives for the ground water in the Central Area, and also included remedial alternatives for ground water in the Central Area plus the Flank Areas. The RI also determined that landfill Cell 9 (see Figure 1) is likely the source of the constituents identified in the Central Area. Therefore, active remediation of landfill contents in Cell 9 was also evaluated in the FS. Based on the results of the Human Health Risk Assessment and the Ecological Risk Assessment, no active remediation is warranted for surface water or sediments in Rancocas Creek, Smithville Canal, sediment ponds/outfalls, or ground water seeps.

Landfill Contents

For the landfill contents, the primary remedial action objective is to maintain the existing engineering controls that accomplish the following:

• Prevent direct contact with landfill contents

• Reduce leaching ofconstituents to ground water over time

• Control surface water runoff and erosion

12

• Control landfill gas migration.

A secondary remedial action objective for landfill contents is to reduce the mass, toxicity, or mobility ofpotentially hazardous constituents in Cell 9, if feasible.

Ground Water •

For ground water, remedial action objectives are the following:

• Prevent human consumption of ground water from the MLCMS and Middle Wenonah aquifers between the landfill and Rancocas Creek

• Achieve remediation goals established for ground water in the MLCMS and Middle Wenonah aquifers

• Avoid and/or minimize negative impacts to human health or the environment (e.g., the wetlands) caused by active remedial measures.

NJDEP has identified remediation goals for the ground water at the L&D Site as the federal drinking water standards or the New Jersey Ground Water Quality Standards. The more conservative of the two standards would be used as the remediation goal. A summary of these standards can be found in Table 6 (for VOCs) Table 7 (for metals) and Table 8 (for other inorganic parameters). The remediation goals listed include on these tables are chemical-specific ARARs for the Site.

Although the goal is to achieve the remediation goals in ground water, certain factors (e.g., high background concentrations ofmetals) make it unclear whether this goal can be achieved for all parameters.

DESCRIPTION OF REMEDIAL ALTERNATIVES

CERCLA §I21(b)(l), 42 U.S.C. §9621 (b)(l) mandates that a remedial action must be protective ofhuman health and the environment, cost effective, and utilize permanent solutions and alternative treatment technologies or resource recovery technologies to the maximum extent practicable. Section 121 (b)(1) also establishes a preference for remedial actions that employ, as a principal element, treatment to permanently and significantly reduce the volume, toxicity or mobility of the hazardous substances, pollutants and contaminants at a Site. CERCLA §121 (d), 42 U.S.C. §9621 (d), further specifies that a remedial action must attain a level or standard of control of the hazardous substances, pollutants and contaminants, which at least attains ARARs under federal and state laws, unless a waiver can be justified pursuant to CERCLA §121(d) (4), 42 U.S.C. §9621 (d)(4).

Based on the information contained in the RI and FS Reports, the Human Health Risk Assessment, and the Ecological Risk Assessment, the Proposed Plan evaluated, in detail, five

13

remedial alternatives for the Site. All remedial alternatives, except Alternative 1 included the common elements that are discussed below.

Common Elements of Active Remedial Alternatives

All the alternatives require maintenance of the landfill as directed in the approved landfill closure plan, which is expected to satisfy the RAOs with respect to the landfill contents (with the exception ofachieving contaminant reduction in Cell 9). The active alternatives (Alternatives 2 through 5) discussed below include common components. All active alternatives would require the decommissioning of residential wells down gradient of the landfill, water use restrictions, development of a Classification Exception Area (CEA) between the landfill and Rancocas Creek, and establishment of a long-term ground water monitoring program which will address the RAOs for ground water. The long-term ground water monitoring plan will determine whether the remediation goals for ground water are being achieved and ensure the protectiveness of the remedy. In addition, a water line extension down gradient of the landfill will be installed if Burlington County does not provide NJDEP with written documentation from the Board of Chosen Freeholders of Burlington County within 6 months that the properties along Rabbit Run and Hand Lane will be acquired by March 2006, or otherwise satisfactorily demonstrate to NJDEP that it will acquire these properties in a reasonable timeframe.

Remedial Alternatives

Alternatives for active remediation of ground water in the Flank Areas were developed in the FS, but were not carried forward into the combined remedial alternatives for several reasons. First, as discussed in detail in the FS report, impacts to ground water due to the landfill are minimal in the Flank Areas and, therefore, active remediation in the Flank Areas would not significantly add to the effectiveness ofthe overall remedy. Second, the implementability of remedies that include the Flank Areas is considered low compared to remedies for the Central Area, because remedial alternatives involving ground water extraction for the entire Site plume (including the Flank Areas) require a much greater pumping rate (as much as 200 gallons per minute (200 gpm» than for alternatives for the Central Area (30 gpm), and the result is a much greater potential for negative impacts to wetlands when the Flank Areas are included. Ground water modeling conducted as part of the FS indicates as much as three feet of drawdown might occur beneath wetlands down gradient of the Eastampton section of the landfill for remedial alternatives involving ground water extraction for the entire Site plume (including the Flank Areas), compared to less than 0.5 feet of drawdown near wetlands down gradient of the Central Area in the alternatives with extraction only in the Central Area. Also, with 200 gpm oftotal extraction (for the entire Site plume), the discharge option to the Publicly Owned Treatment Works (pOTW) appears infeasible, and the implementability of other treatment/discharge options that meet all discharge standards to surface water or ground water is considered to be low.

After comparing the various on-Site and off-Site ground water treatment and disposal options, only the POTW was retained to address extracted ground water (or excess extracted water for Alternative 3).

14

The contaminant levels in the Flank Areas are expected to decline slowly over time, through degradation processes in the ground water, and because there do not appear to be significant continuing new sources of contamination to the Flank Areas. All the remedial alternatives (other than Alternative 1) include long-term monitoring of ground water in the Flank Areas for any constituents exceeding the remediation goals. Also, all final alternatives (other than Alternative 1) include institutional controls to prevent consumption of ground water down gradient of both the Central Area and the Flank Areas, between the landfill and Rancocas Creek.

Because all of the remedial alternatives result in leaving contamination on Site above levels that would not allow for unrestricted use of the landfill or the ground water, five-year reviews would be conducted, unless determined otherwise.

Alternative 1 Landfill Management and No Further Ground Water Action

Estimated Capital Costs: $0 Present Worth ofAnnual Costs: $0 T ota! Cost: $0

Regulations governing the Superfund program generally require that the "no action" alternative be evaluated to establish a baseline for comparison with other, active alternatives. For the L&D Site, the appropriate closure for the landfill has already been addressed by NJDEP; therefore, Alternative 1 would require no further action beyond what is mandated by the approved landfill post-closure plan. Under this alternative, no further action would be taken at the Site to prevent exposure to ground water contamination. The ground water contamination would not be treated or contained. Ground water contaminant concentrations would not meet the remediation goals v.rithin a reasonable time frame.

Alternative 2 Landfill Management, Ground Water Extraction (Central Area), and Discharge to POTW

Estimated Capital Costs: $ 807,700 Present Worth ofAnnual Costs: $5,860,862 Total Cost: $6,668,562

Alternative 2 consists of continued maintenance of the landfill, augmented with a down gradient plIDlping remedy to address the ground water contamination in the Central Area.

Alternative 2 includes the construction and operation of a ground water extraction system in the Middle Wenonah aquifer, with three or four ground water wells located in the Central Area operating at a combined pumping rate of approximately 30 gpm. This alternative targets the most highly contaminated portion of the ground water for active remediation. The collected water would be discharged to a POTW (similar to what is currently done with the landfill leachate). This alternative would require an expanded ground water monitoring program to evaluate and optimize the effectiveness of the down gradient pumping remedy. The estimated timeframe for operation of the extraction system is 30 years.

15

Alternative 3 Landfill Management, Enhanced Aerobic Treatment of Cell 9, Ground Water Extraction (Central Area), and Recirculation into Landfill

Estimated Capital Costs: $1,734,000 Present Worth of Annual Costs: $2,217,329 Total Cost: $3,951,329

This Alternative would require continued maintenance of the landfill, but also includes construction and operation ofa system for enhanced aerobic treatment of Cell 9 of the landfill. This would include air injection and leachate/ground water recirculation to stimulate biodegradation of waste in this source area. This is an implementable technology that has been successfully implemented at other landfills to enhance contaminant mass reduction within the landfill.

Alternative 3 includes the construction and operation of a ground water extraction system in the Middle Wenonah aquifer, as described in Alternative 2. The collected water would be re­circulated, along with landfill leachate, into Cell 9 of the landfill, creating a closed loop. The existing discharge to the POTW would be maintained to address excess water that will periodically be collected. Predictive modeling in the FS, along with experience at other landfills, indicates that enhanced aerobic treatment would achieve substantial source reduction in Cell 9 in approximately two years, as measured by reductions in contaminant levels from landfill leachate. The costs for this alternative were developed assuming two years of enhanced aerobic treatment, coupled with down gradient ground water pumping of the Central Area, to address the landfill source, followed by another three years of ground water pumping alone to achieve the Remediation Goals in the Middle Wenonah aquifer.

Alternative 4 Landfill Management, Ground Water Extraction (Central Area), Vertical Barrier Wall, and Discharge to POTW

Estimated Capital Costs: $1,642,000 Present Worth ofAnnual Costs: $5,452,686 Total Cost: $7,094,686

Alternative 4 is similar to Alternative 2 in that it consists of continued maintenance of the landfill, with a similar down gradient pumping remedy to address the ground water contamination in the Central Area. This alternative would also require the installation ofa vertical slurry wall down gradient of the extraction wells. This vertical slurry wall would provide a down gradient barrier to ground water flow that would limit further migration of contamination, thereby increasing the effectiveness of the extraction wells in removing the contamination. It is estimated that the extraction of ground water with discharge to the POTW would occur over thirty years.

16

Alternative 5 Landfill Management and In-Well Air StrippinglBioaugmentation (Central Area)

Estimated Capital Costs: $1,487,500 Present Worth ofAnnual Cost: $4,193,683 Total Cost: $5,681,183

In addition to the continued landfill management requirements common to all alternatives, Alternative 5 includes construction and operation of a network of approximately 30 in-well circulation units in the Central Area to remove VOCs in-situ, and to add oxygen and possibly reagents to the subsurface to promote bioremediationloxidation. It is estimated that this treatment would occur over thirty years.

SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

In selecting a remedy, NJDEP considered the factors set out in CERCLA § 121, U.S.C. §9621, by conducting a detailed analysis of the viable remedial alternatives pursuant to the NCP, 40 Code of Federal Regulations (CFR) §300.430(e) (9) and Office of Solid Waste and Emergency Response (OSWER) Directive 9355.3-01. The detailed analysis consisted of an assessment of the individual alternatives against each of nine evaluation criteria and a comparative analysis focusing upon the relative performance of each alternative against those criteria.

The following "threshold" criteria must be satisfied by any alternative in order to be eligible for selection:

Threshold Criteria

1. Overall protection of human health and the environment addresses whether or not a remedy provides adequate protection and describes how risks posed through each pathway are eliminated, reduced, or controlled through treatment, engineering controls, or institutional controls.

2. Compliance with applicable or relevant and appropriate requirements (ARARs) addresses whether or not a remedy will meet all of the applicable or relevant and appropriate requirements of other federal and state environmental statutes and requirements or provide grounds for invoking a waiver.

The following "primary balancing" criteria are used to make comparisons and to identify the major trade-offs between alternatives:

Prima" Balancing Criteria

3. Long-term effectiveness and permanence refers to the ability of a remedy to maintain reliable protection of human health and the environment over time, once cleanup goals have been met.

17

4. Reduction of toxicity, mobility, or volume through treatment refers to a remedial technology's expected ability to reduce the toxicity, mobility or volume ofhazardous substances, pollutants or contaminants at the Site.

5. Short·term effectiveness addresses the period of time needed to achieve protection and any adverse impacts on human health and the environment that may be posed during the construction and implementation period until cleanup goals are achieved.

6. Implementability is the technical and administrative feasibility ofa remedy, including the availability of materials and services needed to implement a particular option.

7. Cost includes estimated capital and operation and maintenance costs, and net present worth costs.

The following "modifying" criteria are considered fully after the formal public comment period on the Proposed Plan is complete:

Modifying Criteria

8. EPA acceptance indicates whether, based on its review of the FS and Proposed Plan, the EPA supports, opposes, and/or has identified any reservations with the selected alternative.

9. Community acceptance is assessed based on a review of the public comments received on the technical reports and the Proposed Plan.

Overall Protection Of Human Health And The Environment

Alternative 1 is rated low with respect to protection of human health because it does not address the potential risk to human health posed by the possible use of ground water from the Middle Wenonah aquifer. Alternatives 2,3,4, and 5 meet the RAOs and would be protective of human health. Each alternative addresses impacted ground water from the Middle Wenonah aquifer, and the decommissioning of ground water supply wells that are screened in the aquifer down gradient of the landfill. The protection of the environment is considered to be high for all alternatives, as the current risk to the environment from the Site, as determined in the ecological risk assessment, is low.

Compliance With ARARs

Alternative 1 does not meet the chemical-specific ARARs for clean-up of the ground water in the Middle Wenonah aquifer in the Central Area, and is rated low. Alternatives 2-5 would meet the chemical-specific ARARs for ground water, although the timeframes needed before ARARs are achieved vary. Only Alternative 3 addresses the source of the ground water contamination by actively treating Cell 9, and offers the potential to achieve the ground water Remediation Goals in as little as five years, whereas Alternatives 2, 4 and 5 all rely on long term pumping and treating to control, and slowly remediate, the aquifer. While the Remedial Action Objective for

18

the ground water is to achieve the chemical-specific ARARs, certain factors (e.g., high background concentrations ofmetals) make it unclear whether this goal can be achieved for all parameters. None of the active remedial alternatives were considered more likely to achieve the Remediation Goals than the others, so this was not a major consideration when evaluating compliance with ARARs.

Location-specific ARARs concerning wetlands will need to be evaluated during the remedial design stage to determine whether operation of ground water extraction remedies will impact wetlands that exist within the areas to be remediated. Negative impacts from any of these alternatives to wetlands are not anticipated, given the focus on the Central Area and the distance ofmore than 700 feet to the nearest down gradient wetlands. Ground water modeling in the FS for the scenarios with ground water extraction in the Central Area indicates that drawdown north of Shreve Street, where wetlands are located down gradient of the Central Area, will be less than 0.5 feet.

Compliance with any action-specific ARARs would be addressed in the design stage for any of the alternatives, including the performance of a Stage IA cultural resource survey.

Long-Term Effectiveness And Permanence

The long-term effectiveness of Alternative 1 is significantly lower than that of the remaining four alternatives because Alternative 1 does not address the toxicity, volume, or mobility of constituents that are in the Middle Wenonah aquifer. Therefore, Alternative 1 is rated low for this criterion. Alternatives 2, 4, and 5 are rated moderate with respect to long-term effectiveness and permanence. Each alternative addresses impacted ground water from the Middle Wenonah aquifer, and the decommissioning ofground water supply wells that are screened in the aquifer down gradient of the landfill. Alternatives 2, 4 and 5 do not address the ground water impact source within the landfill. Therefore, the length of time that these technologies would need to operate is long, i.e., thirty years as opposed to five years for Alternative 3. Alternative 5 is rated slightly lower than the other alternatives because, in addition to having no source control, effectiveness of in-situ control and treatment is less certain. Alternative 3 is rated high because this alternative provides a technology to potentially degrade the source of the ground water impacts, which is favorable for long-term effectiveness and permanence.

Reduction Of Toxicity, Mobility, And Volume

Alternative 1 does not reduce the toxicity, mobility, and volume of the residual contamination because it does not include active remediation. Alternatives 2, 4, and 5 are rated moderate with respect to reduction in toxicity, mobility, and volume. Each alternative addresses impacted ground water from the Middle Wenonah aquifer, but do not address the ground water impact source within the landfill. Alternative 3 is rated high because this alternative provides a technology to potentially degrade the source of the ground water impacts, which is favorable for reduction in toxicity, mobility, and volume.

19

Short-Term Effectiveness·

Alternatives 1, 2, and 5 have minor short-term risks to workers that can be mitigated using standard health and safety protocols. With Alternative 3 there is the possibility that recirculation of extracted ground water may increase movement of contaminants in the capped landfill cell in the short-term. However, over time, the recirculation and air injection will reduce the overall contaminant concentrations and movement. An increased short-tenn risk to workers is expected from implementation ofAlternatives 3 or 4 relative to the other alternatives due to construction of the enhanced aerobic treatment within the landfill andlor due to the slurry wall construction. Risks to workers can be mitigated using standard health and safety protocols. Air monitoring will be necessary to detennine the potential risk to the community from released VOCs during construction of the soil-bentonite wall, and also during construction of the distribution system associated with the Enhanced Aerobic Treatment. Standard health and safety protocols for work on hazardous sites will mitigate the risks.

Some environmental impacts to wetlands may result from implementation ofAlternatives 2, 3, or 4..Further evaluation during the remedial design of the potential wetlands impacts will be necessary to assess whether wetlands will be impacted, and whether mitigation of wetlands will need to be addressed.

Alternatives 1,2, and 5 can be implemented within one construction season after obtaining the necessary permits and access agreements for the water line. The remaining alternatives can be implemented within one year of obtaining the necessary permits.

Implementability

The technical and administrative implementability ofAlternatives 1 and 2 is high. The technical implementability of Alternatives 3, 4, and 5 is expected to be moderate due to the relatively innovative application of the Enhanced Aerobic Treatment for Cell 9, the required depth of the soil-bentonite wall, and the inconclusive evidence of effectiveness of the in-situ well circulation system for similar constituents. OfAlternatives 3, 4 and 5, Alternative 3 has the highest likelihood of success.

Cost

The total cost is a sum of the capital (construction) cost and the present worth of the operation and maintenance of the alternative over time. Present worth is based on a discount rate of seven percent and a 3D-year period. The present worth cost for the alternatives are as follows, from most expensive to least: Alternative 4 (ground water extraction with vertical barrier) $7.09 million, Alternative 2 (ground water extraction, discharge to POTW) $6.67 million, Alternative 5 (in-situ ground water treatment) $5.68 million, and Alternative 3 (Cell 9 treatment with ground water extraction/recirculation), $3.95 million. There are no additional remedial costs associated with Alternative 1.

20

Ofthe active remedies, Alternative 3 has the lowest cost due to the assumption that the enhanced aerobic treatment would be successful in two years, followed by approximately three years of pumping with discharge to the POTW to meet the Remediation Goal in the Middle Wenonah aquifer. After those five years, only long-tenn ground water monitoring costs would be incurred. All of the other alternatives are assumed to operate over the entire 30-year horizon, resulting in higher total costs.

USEP A Acceptance

The USEPA concurs with the selected remedy. USEPA's concurrence letter is attached (Appendix 11).

Community Acceptance

Community acceptance of the preferred alternative presented by the Proposed Plan was assessed during the public comment period. Based on the comments received, the community generally accepts this approach. The attached Responsiveness Summary (Appendix III). addresses all verbal comments received at the public meeting and the meeting with the Rancocas Creek Association, as well as written comments received during the public comment period.

PRINCIPAL THREAT WASTES

The landfill contents of Cell 9 are considered "principal threat wastes" because the contents of Cell 9 act as a continuing source of ground water contamination. Only Alternative 3 (Enhanced Aerobic Treatment of Cell 9, Ground Water Extraction of the Central Area, and Recirculation into Landfill) directly addresses the source materials constituting principal threats through treatment.

SELECTED REMEDY

Based upon consideration of the requirements of CERCLA, on the detailed analysis of alternatives, and public comments, the NJDEP and EPA have detennined that Alternative 3 is the appropriate remedy because it best satisfies the requirements ofCERCLA §121, 42 U.S.C. §9621, and the NCP's nine evaluation criteria for remedial alternatives, 40 CFR §300.430 (e) (9).

This alternative consists of the following:

• Construction and operation of a ground water extraction system in the Middle Wenonah aquifer in the Central Area to provide hydraulic containment,

• Construction and operation ofEnhanced Aerobic Treatment (Cell 9), whereby leachate and ground water would be re-circulated into the landfill along with appropriate air injection to enhance contaminant degradation. Excess water would be discharged to the POTW for treatment if necessary,

21

• Long-term monitoring for ground water exceeding the remedation goals, including in the Flank Areas not targeted for active extraction and treatment,

• Continued maintenance of the existing final cover system on the landfill,

• Continued landfill leachate and gas monitoring, collection, and disposal,

• Decommissioning of residential water-supply wells down gradient of the landfill,

• Continued maintenance of the Site security.

Regarding residential properties down gradient of the landfill, Burlington County is in the process ofacquiring properties along Rabbit Run and Hand Lane. The County would like to acquire these properties for various reasons, including:

• The dwellings are served by on-site septic systems located in the floodplain or adjacent to Rancocas Creek. These septic systems may be responsible for the exceedance of the water quality standard for fecal coliform in the North Branch of the Rancocas Creek.

• The dwellings are in the floodplain and therefore are subject to frequent flooding.

• These properties lie adjacent to Smithville Park, and the County would like to create a greenway along the North Branch of the Rancocas Creek that would link Smithville Park to other County-owned properties along the Creek and Rancocas State Park.

If the County does not provide NJDEP with written documentation from the Board of Chosen Freeholders of Burlington County within 6 months that the properties will be acquired by March 2006, or otherWise satisfactorily demonstrate to NJDEP that it will acquire these properties in a reasonable timeframe, the following remedy will also be implemented:

• Water line extension to Hand Lane and along the western portion of Rabbit Run, down gradient of the landfill.

If the County does provide written documentation to NJDEP that it will acquire these properties in a reasonable timeframe, then the water line extension along the western portion of Rabbit Run, down gradient of the landfill, will not be installed.

Currently the residents on Hand Lane and Rabbit Run are provided bottled water by the L&D Company. Those residents will continue to receive bottled water until their property either is acquired by the County or the water line is installed.

Implementation of the selected remedy would be phased, with a first group of three to four ground water extraction wells installed near the landfill that could be augmented in the future by two additional extraction wells in the Middle Wenonah aquifer (near existing wells LDM-206 and LDM-21 0) if sufficient concentration reductions between the landfill and the creek are not

22

observed. These down gradient wells may actually draw contaminants beyond the containment wells at the landfill, and delaying their implementation by approximately one to two years would allow for an opportunity to monitor the effectiveness of the remedy without these wells. If monitoring during this one to two year time frame indicates that the initial pumping program is effective in addressing the area between the landfill and the creek, or indicates substantial concentration reductions such that adequate remediation of that area is considered likely within the subsequent three years, then the two off-site wells would not be implemented.

Based upon experience at other landfills, Enhanced Aerobic Treatment appears likely to be successful at reducing the source of contamination, and in shortening the time required for aquifer restoration; however, the process may lose its effectiveness after a limited period of time. Under the selected remedy, the Enhanced Aerobic Treatment would continue as long as leachate contaminant concentrations in Cell 9 remain higher than leachate concentrationS in the other landfill cells, and indicator parameters for biological activity, such as temperature and carbon dioxide levels, indicate that biological activity remains enhanced relative to baseline values measured before the treatment begins. NJDEP may also consider the relative cost and effectiveness of this treatment technology when compared to the cost of off-site treatment at a POTW. If conditions indicate that this technology is no longer effective based upon these criteria, the landfill leachate and extracted ground water would then be sent to the POTW for appropriate treatment and disposal (similar to Alternative 2). In the FS, a timeframe oftwo years for active recirculation followed by three years of continued pumping after recirculation (in the Central Area) was assumed for the purpose of estimating costs.

Pumping for ground water containment would continue after the Enhanced Aerobic Treatment until ground water concentrations monitored in the Central Area achieve the remediation goals, or alternatively when it is demonstrated that ground water concentrations in the Central Area are similar to those observed in the Flank Areas. The goal of the selected remedy is to prevent exposure of the public to contaminated ground water and to restore the contaminated ground water to ground water quality standards within a reasonable timeframe. However, due to the high background concentration of metals, it is unclear when this goal of aquifer restoration would be achieved, if ever. In addition, the selected remedy does not include active remediation in the Flank Areas of the plume, and it is unclear how long it would take for this relatively diffuse plume to recover without active treatment. Therefore, NJDEP would plan a phased approach to implementing this remedy, whereby a ground water remedy would be implemented and, after a certain period of operation and monitoring, certain chemical-specific ARARs may potentially be waived for Technical Impracticability (TI), through an Explanation of Significant Differences. A TI waiver may be invoked under one or more of the following conditions, or "triggers": (1) if remaining risks are associated with background conditions or (2) if further improvements to ground water quality appear unachievable.

Based on the information available at this time, NJDEP and EPA believe the selected remedy would be protective ofhuman health and the environment, would comply with ARARs, would be cost-effective, and would utilize permanent solutions and alternative treatment technologies to the maximum extent practicable. The selected alternative also incorporates the statutory

23

preference for the selection of a remedy that involves treatment, as Enhanced Aerobic Treatment would degrade contaminants that are the source of the ground water contamination.

STATUTORY DETERMINATIONS

As previously noted, CERCLA §121(b)(1), 42 U.S.C. §9621(b)(1), mandates that a remedial action must be protective ofhuman health and the environment, cost effective, and utilize permanent solutions and alternative treatment technologies or resource recovery technologies to the maximum extent practicable. Section 121 (b)(I) also establishes a preference for remedial actions that employ treatment to permanently and significantly reduce the volume, toxicity, or mobility ofhazardous substances, pollutants, or contaminants at a Site. CERCLA §121(d), 42 U.S.C. §9621 (d) further specifies that a remedial action must attain a degree of cleanup that satisfies ARARs under federal and state la~s, unless a waiver can be justified pursuant to CERCLA §121(d)(4), 42 U.S.C. §9621 (d)(4). For the reasons discussed below, NJDEP has determined that the selected remedy at the Landfill & Development Site meets the requirements ofCERCLA §121, 42 U.S.C. §9621.

Protection of Human Health and the Environment

Of the five alternatives evaluated, the selected remedy provides the greatest protection ofhuman health and the environment. Enhanced aerobic treatment will degrade the contents ofCell 9 ofthe landfill, which is the source of the ground water impacts. The other alternatives would not degrade the contents of the landfill, therefore this alternative is rated higher. Human health will be protected through the installation of the water line down gradient of the landfill (if the County does not acquire the properties), decommissioning of residential wells down gradient of the landfill and implementation ofa Classification Exception Area. Ground water will eventually be restored to State Ground Water Quality Standards or Federal MCLs. Maintenance of the landfill will continue as specified in the approved landfill closure plan, including maintenance ofthe cap.

Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)

The National Contingency Plan, Section 300.430(f)(ii)(B) requires that the selected remedy attain Federal and State ARARs. The remedy will comply with the following action-, chemical- and location-specific ARARs identified for the Site and will be demonstrated through monitoring, as appropriate.

Action-Specific ARARs:

• NJ.A.C. 7:26E - Technical Requirements for Site Remediation

• P.L. 1997 c. 39 - Brownfield and Contaminated Site Remediation Act

• 40 CFR 6301 (c) - National Historic Preservation Act

24

Chemical-Specific ARARs (the chemical-specific .ARARs for ground water are listed in Tables 6, 7 and 8).

• 40 CFR Part 141- Federal Safe Drinking Water Act Maximum Contaminant Levels (MCLs)

• N.J.A.C. 7:9 et. seq. - Ground Water Quality Standards

• Air standards set forth in 40 CFR 50 and N.J.A.C. 7:27 et. seq.

Location-Specific ARARs:

• N.J.A.C. 7:7 A - New Jersey Freshwater Protection Act

Cost Effectiveness

Each of the alternatives has undergone a detailed cost analysis. In that analysis, capital costs and annual costs have been estimated and used to develop the total cost. The cost effectiveness ofan alternative is determined by weighing the cost against the alternative's ability to achieve ARARs and remedial action objectives. The selected remedy for the Site, Alternative 3, will achieve the goals of the response actions and is cost-effective because it will provide the best overall effectiveness in proportion to its costs.

Utilization of Permanent Solutions and Alternative TreatInent Technologies to the Maximum Extent Practicable

The selected remedy meets the statutory requirement to utilize permanent solutions and treatment technologies to the maximum extent practicable.

Preference for Treatment as a Principal Element

The selected remedy satisfies the statutory preference for remedies that employ treatment as a principal element.

Five-Year Review Requirements

Because this remedy will result in hazardous substances, pollutants, or contaminants remaining on­site above levels that allow for unlimited use and unrestricted exposure, a statutory review will be conducted at five-year intervals starting after initiation of the remedial action to ensure that the remedy is, or will be, protective ofhuman health and the environment.

DOCUMENTATION OF SIGNIFICANT CHANGES

The Proposed Plan for the Landfill and Development site was released for public comment in May 2004. The Proposed Plan identified Alternative 3, Enhanced Aerobic Treatment of Cell 9,

25

Ground Water Extraction of the Central Area, and Recirculation into Landfill, as the Preferred Alternative for the site. NJDEP reviewed all written and verbal comments submitted during the public comment period. It was determined that no significant changes to the remedy, as originally identified in the Proposed Plan, were necessary or appropriate.

26

2402003011 A.DWG

.LE.G£NO SWALES (USUALLY DRY) ~ LANDFILL CELLS FENCE LINE EXTENT OF LEACHATE

~ '"",," SLOPE ASSOCIATED WITH COLLECTION SYSTEM AND THE LANDFILL INTERMEDIATE LINER ~

J.IIS::Z!I§. MLCMS AQUIFER -N­.. MONITORING WELL [lIJII-1{)6] MIDDLE WENONAH AQUIFER

o PIEZOMETER IIlllE-2061 ENGLISHTOWN AOUIFER

o LEACHATE COLLECTION MANHOLE

Ii

NORTI"1EAST Olmi S(OIUENTATION

PONIl

MOUNT HOllY SECTION

~ [tlJll-2J.

Ii.liEIDl SECTION NOTES:

1. WELLS 102M AND LDE -1 WERE FOUND TO HAVE BROKEN CASINGS. . ....... . o 1000 2000

.._, .... II I2. lHE FOLLOWING WELLS NO LONGER EXIST: 107M AND LDE-4. SCALE IN FEET

3. THE FOLLOWING WELLS COULD NOT BE LOCATED: PZ-26S (MAY NO LONGER EXIST). PZ-26M (MAY NO LONGER EXIST). AND LDM-211 (BURIED IN ASPHALT).

Figure 1. Landfill Cells, Extent of Leachate Collection System and Intermediate Liner, and Gas Extraction Wells. ~G,~"QTrans, Inc. '--------------------------- ­

2402003012A.DWG

~

SWALES (USUALLY DRY) EXTENT OF LEACHATE COLLECTION SYSTEM AND INTERMEDIATE LINER

".,,""'" SLOPE ASSOCIATED WITH THE LANDFILL MONITORING WELL

FENCE LINE ~ ~ MLCMS AQUIFER o PIEZOMETER -N­[I.0Il-206] MIDDLE WENONAH AQUIFER

CREEK LEVEL LOCATIONS I ~ ENGLISHTOWN AQUIFER

\\

~,,~P~'~[·;·;""· \\ 3.82

\\ :\ tF;:::;··:~:··~:.-:.:~ :-~­

---;:"~~"::,~';.:"-,:,

i;

/.Ii if !/ If H

II if

\\ ORAl_ i\

\\

\\

!illIES;

1. WELLS 102M AND LDE-1 WERE FOUND TO HAVE BROKEN CASINGS.

2. THE FOLLOWING WELLS NO LONGER EXIST: 107M AND LDE-4 .

.3. THE FOLLOWING WELLS COULD NOT BE LOCATED: PZ-26S (MAY NO LONGER EXIST). PZ-26M (MAY NO LONGER EXIST). AND LDM-211 (BURIED IN ASPHALT).

Figure 2. Potentiometric Surface Map, MLCMS Aquifer, August 12,1999.

-------

2402003013A.DWG

.w>END SWALES (USUALLY DRY) EXTENT OF LEACHATE

COLLECTION SYSTEM AND INTERMEDIATE LINER

'if'!··",'\"'-" SLOPE ASSOCIATED WITH THE LANDFILL MONITORING WELL

FENCE LINE

.- ~ ~ MLCMS AQUIFER -N­0 PIEZOMETER [ll.HIl6) MIDDLE WENONAH AQUIFER

<I> CREEK LEVEL LOCATIONS IILit-1061 ENGLISHTOWN AQUIFER

if

ri \\ MOUNT HOllY if 1\ IiH j,1\\ .,

"i\ \j i\

\\

(UlIHOJ) J5.44 • ...... ------ SECTION

~~' ,'.-----­",,' .",.;' [1.DIII-2) - ..........

__ -~' ,..' , 40.77 , .....P'"

",.,,,; ' .....,,,,,"" , 1. WELLS 102M AND LDE-l WERE FOUND TO HAVE.... ... ...

BROKEN CASINGS. ... ......... o 1000 2000 2. THE FOLLOWING WELLS NO LONGER EXIST: 107M ...... ~I~--~--~I~~~~I

AND LDE-4. ... .......... " SCALE IN FEET 3. THE FOLLOWING WELLS COULD NOT BE LOCATED:

PZ-26S (MAY NO LONGER EXIST). PZ-26M (MAY NO LONGER EXIST). AND LDM-211 (BURIEO IN ASPHALT).

Figure 3. Potentiometric Surface Map, Middle Wenonah Aquifer, August 12, 1999.

I

2402003014A.DWGr==:­~

SWALES (USUALLY DRY) EXTENT OF LEACHATE

FENCE LINE COLLECTION SYSTEM AND INTERMEDIATE LINER

t;!!',[;;~":"~ SLOPE ASSOCIATED WITH THE LANDFILL MONlTORING WELL.. ~

~ MLCMS AQUIFER -N­0 PIEZOMETER !ll.OI-1(6) MIDDLE WENONAH AQUIFER IlD<-201l I ENGLISHTOWN AQUIFER

~......... ~ "tl['='!!'ii!:':""=;""'--===r-=••S ~- ........ -- ~~ \~ If

!J-·~~'~~'~''''f;\L:\JlrAJ.L.-'\\\(,::::::,,::::-,- .ff

H

i tl! If

Jr...;;;~:~:.~'~~~"~1~~':~:==-------:==:-------:~::]L_ ,IMOUNT HOllY SECTION' g~"'MWATEI;J-'<~' .:::,.,,::~:"'"_.. "_~""'''' <,r (gJ ..... ":>...,~':::~H ....:t.I~ ..r_.~~~=TlON, '

26.18 .<»>..:....,:::.?,-:~~--~..,~_~ =~~'.~ .. j -'" '. Iilll

------------==:J"--------.~.._-~. 27,61 ll.QIES; ~t ~:·-:~!L.::...,..·...... EASTAMPTON SECTION

1. WELLS 102M AND LDE-1 WERE FOUND TO HAVE 28.23 ~ BROKEN CASINGS. .. :"-~~·.::::-:~.---':""';;"'.-,,=:, .._------------28­

2. fHE FOLLOWING WELLS NO LONGER EXIST: 107M ""> --'" o 1000 2000

3. ~:~ ~~~~G WEUS COUW ~ W~:T~E~D~:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~:~~~~~~'~:~--~~~Nm ~I~riiiiil~iiiiiiiiiiIi~1~~~~IPZ-26S (MAY NO LONGER EXIST), PZ-26M (MAY .<>::... 30-NO LONGER EXIST), AND LDM-211 (BURIED IN ASPHALT). OCII V SCALE IN FEET30.16

4. • WELL LD-9 WAS FLOWING AT GROUND SURFACE, 21.08

FT MSL IS TOP OF CASING ELEVATION.

Figure 4. Potentiometric Surface Map, Englishtown Aquifer, August 12, 1999.

! / ',~ ~". . -,',

''''-,:::;»''_( "f'

) ~ :.~;!,1:r;-:-..;~~ ::'.';.H.';'.~

i-,;;')fF!1[).':;'"

e:ASTAMPTON SECTION ,

-"' ..... ~;. .. -~i~·,:.;l~/:.,:;)~

, /

/; / l'~·~~;~~~~~~:~:~··J'~ ~._.~,t)

~:-:.,~ ,~::/JL('~rh~i

2402003015A.DWG

I \

I I I I

I

I

.l.£G£!:ID

,)';~\_::Jl=:-:-,--' SWALES (USUALLY DRY)

/ \ FENCE LINE // ) \, SLOPE ASSOCIATED WITH ~ // THE LANDFILL

/ . -N­\\. \ MONITORING WELL NOT SAMPLE,// \. - .---.., // /1o NO VOCs EXCEED GW QUALITY CRITERIA\\ // ,/ / /~.~.- ..::~.~:',~, \.'-..Ii"\\ "... '~ \ ~ ONE OR MORE VOCs EXCEED GW QUALITY CRITERIA

'-. "'-.:'-. \ \:\(~~~.=~-.-~~) \\\,\ 1\

\i.' ,

,,0--' ­'--'~ .<--'--'-, ') :~;.'~', ~·~:·'i;~~·:;)t{-,·,';:.~,::.i-;~,~:'-\~~\,\"I"

~~f(!_' '-, '.. ~":::::: ':::·-::::·:::::;;·~:::::.-_··.7 _ ,', .J \~'.\ -'--.',-:j

-~~ ':':="~'....:.:..._ ~_ ' F

~. ~ ~;i;,._ "_=-':"'-::::':".:-_. _._~t, 11\\"'....... .~/' .- .:;. "-":~::;:'-::'~~;~;:M: .....,.:-_--_~.o,s.,.~ -. ' . . .~... ,·Q,·,:.,-.'}·.j.!}.~~.i

• OC'" C " "".",,"--- ' ,:"<~,,y-' '- ,,"'.q)r~",--:.5,;li.'[:; \\ WS-2oP<··.................\-- .•:~l' ...... ,..... '->'\:'-:'-l;{" '\'\ ..- .-.... .....

(r" -'" -"- ~b~g~,~::j;?U;Q:P-2A \' \, ':I;"?-~~"~;~LDS-210~O_.,LOS.-.~~\.. If \'(~ _ _ _ .. .........

'\;!:'~ ~ -:. .... ::,..............,' W-~~ .. "" ,~.~

\

MOUNT HOllV SECTION ;~

i\

\\~::::c,=c== ...:::~~~;,::~~:~:~~~:~:~~.:_ ./

ii ii I'

")'\ "'<:_._ I

\\ _./~ •

II .~~tJt:.>}.*,~'~fi·-' "'-'~:: :::"~~"~r:'!ffl!i>""~~;"'::':'\'''"' -:~=::::::-:_.,:~"~~~'I'" ~'--, ~:~.~~::::J, ... ~>o> •• " / _.

.<-.:~ .:::~:t~,~ ,~,.." ••':••~.:.:::.. {..1'~~~!it.gl.~~~.:..~~.:~~.:l;,>r..:;;.:..;.>1"~"-~.

ABBREVIATION PARAMETER NJGWQS (ug/L)

MCL (ug/L)

BEN Senzene 1 5 CB Chlorobenzene <I 100

-~'". '-:.­'-'- '-,

OlOS-202

o 1000 2000 1 1 1

SCALE IN FEET

NOTE: WELL 2S NOT SAMPLED DUE TO INSUFFICIENT WATER LEVEL.

Figure 5. VOCs Exceeding Groundwater Criteria, RI Sitewide Sampling (1999), MLCMS Aquifer.

SWALES (USUALLY DRY)

FENCE: LINE ~ SLOPE ASSOCIATED WITH THE LANDFILL

-N-MONITORING WELL NOT SAMPLED

o NO VOCs EXCEED GW QUALITY CRITERIA I ~ ONE OR MORE VOCs EXCEED GW QUALITY CRITERIA

® CENTRAL AREA. FRINGE ZONE

• CENTRAL AREA. CORE ZONE

o 1000 2000 I I

SCALE IN FEET

CB 100

NOTE: WELLS 107M AND LDM-211 NO LONGER EXIST. WELL 102M HAD BROKEN CASING.

Figure 6. VOCs Exceeding Groundwater Criteria, RI Sitewide Sampling (1999), Middle Wenonah Aquifer.

-----2402OOlO23A.DWG

VOCs Exceeding Groundwater Criteria Sitewide Sampling r Middle Wenonah Aquifer and Proposed Remediation System L.OU-210(uwt.) UlU-208fup'L)

1.2..ocA: MEK: MlBK: ACE:

./ PEN: CtS-1.2: Me:

/ /

TOl:

"'"

,3QJ ,8OOJ7&OJ 17000 6400400DD

2aOOD '6000 39000 38000 1400 280J 170 "OJ.,OJ7600 ....,8200

270J28J

;) ~ ./ -N­

" I

~

o

•

U:'f-o•.f·,lO:<

0_TION

NOTE: WElLS 107M AHO lDW-211 NO LONGER EXIST. WElL 102W HAD BROKEN CASING,

-­ .........,.. NJGlIWlS ""­....., 1..... 1 ClS-11 c..-,~

Me -"""" PCE T_

TOl T....

"'" T_

YC ""'­

,. "'"

o

o 700 1400 ;;oJ I~

SCALE IN FEET

P........... IUGWQS

lo¢J In

1..... 1 ,2<lCo, ,..-­u __"..,. "'" 2_-­ ""- - ... "'" --­ ... BEN --­co ".) Figure 7. Selected Alternative.

LEGEND

PUMPING WELL

AIRIWATER REDISTRIBUTION POINT

PIPING TO POTW FORCEMAIN

PIPE TO REDISTRIBUTION POINTS

SWALES (USUALLY DRY)

FENCE LINE SLOPE ASSOCIATED WITH THE LANDFILL

MONITORING WELL NOT SAMPLED

NO VOCs EXCEED GW QUALITY CRITERIA

ONE OR MORE VOCs EXCEED GW QUALITY CRITERIA

CENTRAL AREA. FRINGE ZONE

CENTRAL AREA. CORE ZONE

. / /

;a,e...G.~QTranS.lne.

TABLE 1

Landfill and Development Site

Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations

Scenario Timeframe: CurrentIFuture Medium: Groundwater in Middle Wenonah. Central (core) ~V~ ..," ,u. II.....• ....

Exposure Chemical of Concern Concentration Point Detected

Min Max

Tap Water Arsenic 5.2e-+{)0 2.0e-+{)1

1.2-Dichloroethane 6.0e-01 1.8e-+{)3

2-Butanone 4.0e-+{)0 6.4e-+{)3

4-Methyl-2-Pentanone 6.0e-01 2.8e-+{)3

Acetone 2.0e-+{)0 3.ge-+{)3

Benzene 3.0e+OO 1.4e-+{)2

Methylene Chloride 5.0e-01 2.1e-+{)3

Toluene 3.0e-01 1.7e-+{)3

Vinyl Chloride 2.0e-+{)0 2.Be-+{) 1

Key

ug/L: micrograms per liter; part per billion UCL - N: 95% Upper Confidence Limit of Log Normally Distributed Data MAX: Maximum Concentration

Concen­tration Units

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

Frequency Exposure of Detection Point

Concen­tratlon

617 2.0e-+01

617 1.8e-+{)3

517 3.6e-+{)3

617 2.8e-+{)3

417 3.ge-+{)3

517 1.4e-+{)2

617 2. 1e-+{)3

617 1.1e-+{)3

517 2.2e-+{)1

Exposure Point

Concen­tratlon Units

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations

Statistical Measure

MAX

MAX

UCL-N

MAX

MAX

MAX

MAX

UCL-N

UCL-N

The tables present the chemicals of concem (COCs) and exposure point concentration for each of the COCs detected in the central core of the Middle Wenonah aquifer. In addition. this table includes the range of concentrations detected for each COCo as well as the frequency of detection (i.e.• the number of times the chemical was detected in the samples collected at the site). the exposure point concentration (EPC). and how the EPC was derived. Acomplete list of all chemicals that were quantitatively evaluated in the central core of the Middle Wenonah Aquife. as well as all other media that were sampled in the remedial Investigation. can be found in the Human Health Risk Assessment

Page 1of 1

TABLE 2

Landfill and Development Site

Cancer Toxicity Data Summary

Pathway: Ingestion, Dermal

Chemical of Concern Oral Cancer Slope Factor

Units Adjusted Cancer Slope

Factor (for Dennal)

Slope Factor Units

Weight of Evidencel Cancer

Guideline Description

Source Date

Arsenic 1.5e+OO I/(mglkg.<Jay) 1.5e+OO 1/(mglkg.<Jay) A IRIS 11130100

1,2-Dichloroe\l1ane 9. 1e-02 I/(mglkg.(jay) 9.1e-02 11(mgikg.<Jay) 82 IRIS 11/30/00

2-Butanone NIA NIA NIA NIA NIA NlA NIA

4-Mell1yl-2-pentanone NIA NIA N/A N/A NIA NlA NIA

Acetone N/A N/A N/A NlA N/A N/A N/A

Benzene 5.56-02 1/(mglkg.<Jay) 5.56-02 I/(mglkg-day) A IRIS 11130100

Methylene Chloride 7.56-03 I/(mglkg.<Jay) 7.5e-03 1/(mglkg-day) 82 IRIS 11/30100

Toluene NlA N/A N/A N/A N/A N/A N/A

Vinyl chloride 1.5e+OO I/(mglkg-day) ·1.5e+OO 1/(mglkg.(jay) A IRIS 11130100

Pathway: Inhalation

Chemical of Concern Unit Risk Units Inhalation Cancer Slope

Factor

Units Weight of Evldencel Cancer

Guideline DeSCription

Source Date

ArseniC 4.3e-03 I/(ug/m3) 1.5e+01 1/(mglkg-day) A IRIS 11130/00

1,2-Dichloroethane 2.6e-05 1/(ug/m3) 9.1e-02 I/(mglkg-day) 82 IRIS 11/30/00

2-Butanone NlA N/A N/A N/A N/A N/A NlA

4-Methyl-2-pentanone NIA NlA NJA NIA NlA NJA NlA

Acetone NIA NIA NIA NIA NIA NIA NlA

Benzene 7.8e-06 1I(uglm3) 2.7e-02 I/(mglkg-day) A IRIS 11130100

Methylene Chloride NIA II(uglm3) 1.7e-03 II(mglkg-day) B2 IRIS 11130100

Toluene N/A NIA . NIA NIA NIA NIA NIA

Vinyl chloride 4.4e-06 11(ug/m3) 1.56-02 II(mglkg.<Jay) A IRIS 11130/00

Key EPA Group:

N/A: No information available

IRIS: Integrated Risk Information System, U.S. EPA

A - Human carcinogen 81 - Probable Human Carcinogen-Indicates that limited human data are available 82 - Probable Human Carcinogen-Indicates sufficient evidence in

animals associated with the site and inadequate or no

Page 1of 2

evidence in humans C - Possible human carcinogen D - Not classifiable as a human carcinogen E- Evidence of noncarcinogenicity

Summary of Toxicity Assessment

This table provides carcinogenic risk infonnation which is relevant to the contaminants of concern. Toxicity data are provided for both the oral and inhalation routes of exposure.

Page 2 of 2

I

TABLE 3

Landfill and Development Site

Non-Cancer Toxicity Data Summary

Pathway: Ingestion/Dermal

Chemical of Concern Cmnlel OI1lIRfD Subchronlc Value

Arsenic Chronic 3.0e-04

1,2-Dichloroethane Chronic 3.0e-02

2-Butanone Chronic 6.lle-Ol

4-Methyl-2-pentanone Chronic B.0e-02

Ace10ne Chronic 1.Oe-Ol

Benzene Chronic 3.0e-03

Melhylene Chloride Chronic 6.0e-02

Toluene Chronic 2.0e-0l

Vinyl chloride Chronic 3.0e-03

Pathway: Inhalation

Chemical of Concern Chroniel Inhalation Subcl!ronlc RfCV.lue

Arsenic N/A N/A

1,2-Dichloroethane Chronic 4.ge-03

2-Butanone Chronic 1.00+OO

4-Methyl-2-pentanone Chronic 3e+OO

Acetone N/A N/A

Benzene Chronic 1.7e-03

Methylene Chloride Chronic 3.Oe+OO

Toluene Chronic 4.0e-0l

Vinyl chloride Chronic 1.00-Ol

OralRm Dennal Oenn.IRfO Primary Target Organ Unit. RID unlb

mglkg-day 3.0e-04 mg/kg-day Skin, vasculil'

mg/kg-day 3.0e-02 mg/kg-day Uver

mg/kg-day 6.0e-0l mg/kg-day Fetal Development

mg/kg-day B.Oe-02 mg/kg-day Uver

mg/kg-day 1.0e-0l mgillg-day Uver, Kidney

mglkg-day 3.0e-03 mg/kg-day Blood

mg/kg-day 6.0e-02 mglkg-day Liver

mglkg-day 2.0e-0l mglkg-day Liver, Kidney

mglkg-day 3.0e-03 mglkg-day Liver

Inh.latlon Inhalation Inhalation Primary Target Organ RICUnlta RfD RfD unlta

N/A N/A N/A N/A

mg/rn3 1.4&-03 mg/kg-day Liver

mglm3 2.99-01 mg/kg-day Fetal Development

mg/m3 B.Se-Ol mg/kg-day Fetal Development

N/A N/A N/A N/A

mg/m3 4.ge-04 mglkg- day NlA

mg/m3 B.Se-Ol mglkg-day Uver

mg/m3 1.1e-Ol mglkg-day CNS

mg/m3 2.99-02 mglkg-day Uver

Combined Sources Om of Uncertllnty of RID: RID: /Modifying Target

Factors Organ

3 IRIS 11/30/00

1000 NCEA 04123101

3000 IRIS 11130/00

N/A HEAST 1997

1000 IRIS 11130/00

3000 NCEA 05I04I01

100 IRIS 11130/00

1000 IRIS 11130/00

30 IRIS 11/30/00

Combined Sources Dates: Uncertllnly 01 /Modifying RfCIRfD:

F.c:tots TIflIII Organ

N/A NlA N/A

3000 NCEA 04/23101

3000 IRIS 04130100

300 IRIS 04130/00

N/A N/A N/A

N/A NCEA 05104101

100 IRIS 11/30/00

300 IRIS 11/30/00

30 IRIS 11130/00

Key N/A: No information available CNS: Central Nervous System Effects IRIS: Integrated Risk Information System, U.S. EPA HEAST: Health Effects Assessment Summary Tabies, U.S. EPA NCEA: National Center for Environmental Assessment U.S. EPA

Summary of Toxicity Assessment

This table provides non-carcinogenic risk information which is relevant to the contaminants of concem. When available, the chronic toxicity data have been used to develop oral ''''''''''K;tI uu"". 1",LJlj/.

Page 1 of 2

Page 2 of 2

TABLE 4

Landfill and Development Site

Risk Characterization Summary· Carcinogens Exceeding a Cancer Risk of 1 E·4 - Reasonable Maximum Exposure (RME)

Scenario Timeframe: Current/Future Receptor Population: Residential ,"" An.. ' ArI"l+ff"hilri

~

Medium Exposure Medium

Exposure Point Chemical of Concern Carcinogenic Risk

Ingestion Inhalation Dermal Exposure Routes Total

Groundwater Groundwater Middle Wenonah Aquifer - Central Area -Tap Water

Arsenic

1,2-Dichloroethane

2-Butanone

4-Methyl-2-pentanone

Acetone

Benzene

Methylene Chloride

Toluene

Vinyl Chloride

4.6&04

2.5e-03

--

-1.2&04

2.4&04

-4.96-04

-

1.2e-02

-

-

-2.9e-04

2.6e-04

-

2.56-05

8.26-07

1.96-05

-

--

3.1e-06

1.5e-06

-

5.Oe-06

4.6&04

1.5e-02

-

-

-

4.1&04

5.06-04

-

5.26-04

Groundwater (Middle Wenonah Aquifer- Central Area) Risk = 1.76-02

Key

- : Route of exposure is not applicable to this medium.

Summary of Risk Characterization· Carcinogens

The table presents risk estimates for the significant routes of exposure. These risk estimates are based on a reasonable maximum exposure and were developed by taking into accou various conservative assumptions about the frequency and duration of the receptors exposure to groundwater, as well as the toxicity of the COCs.

t

Page 1 of 1

TABLE 5

Landfill and Development Site

Risk Characterization Summary· Non·Carcinogens Exceeding a Hazard Index of 1 • Reasonable Maximum Exposure (RME)

Scenario Timeframe: Current/Future Receptor Population: Groundwater Receptor Age: Adult/Child

Exposure Primary Target Non·Carcinogenic Hazard Quotient Medium

Exposure Chemical of ConcernMedium Point Organ

Ingestionlnha atlon Dermal Exposure Routes Total

Ground Ground Middle water water Wenonah

Aquifer, Central Area Tap Water

Arsenic Skin, vascular 2.4~ - 4.2e-03 2.4e+OO

1,2-Dichloroethane Liver 2.1e-+OO 2.3e-+02 1.6e-02 2.3e-+02

2-Butanone Fetal Develop. 2.1e-01 2.2e-+OO 3.6e-04 2.4e-+OO

4-Methyl-2-pentanone Liver 1.2e-+OO 2.5e-+01 1.8e-03 2.6e-+01

Acetone Liver, Kidney 1.4e-+OO - 2.0e-03 1.4e+OO

Benzene Blood 1.6e-+OO 5.0e-+01 4.4e-02 5.2e-+01

Methylene Chloride Liver 1.2e-+OO 4.3e-01 7.9&03 1.7e-+OO

Toluene Liver, Kidney 2.0e-01 1.8e-+OO 1.1e-02 2.0e-+OO

Vinyl Chloride Liver - - - -Total Middle Wenonah Hazard Index TotaUReceptor Hazard Index = 3.2e-+02

Liver Hazard Index = 2.6e-+02

Blood Hazard Index = 5.2e-+01

Skin Hazard Index = 2.4e+OO

Vascular Hazard Index = 2.4e-+OO

Fetus Hazard Index = 2.4e-+OO

,'" thio. .Al,,~

Summary of Risk Characterization· Noncarclnogens

The table presents noncancer (hazard) risk estimates for the significant routes of exposure. These noncancer (hazard) risk estimates are based on a reasonable maximum exposure and were developed by taking into account various conservative assumptions about the frequency and duration of the receptors exposure to groundwater, as well as the toxicity of th COCs.

Page 1 of 1

Table 6 Groundwater Criteria for VOCs

Parameter NJ GWQS (ug/l) Federal MCl (ug/l)

Data Evaluation Criterion (u~1I)

1,1,1-Trichloroethane 30 200 30 1,1,2,2-Tetrachloroethane 2 - 2 1,1,2-Trichloroethane 3 5 3 1 ,1-Dichloroethane 70 - 70 1,1-Dichloroethene 2 7 2 1,2-Dibromo-3-chloropropane NA 0.2 0.2 1,2-Dibromoethane 0.05 0.05 0.05 1,2-Dichlorobenzene 600 600 600 1,2-Dichloroethane 2 5 2 1,2-Dichloropropane 1 5 1 1,3-Dichlorobenzene 600 - 600 1 A-Dichlorobenzene 75 75 75 2-Butanone 300 - 300 2-Hexanone - - -4-Methyl-2-pentanone 400 - 400 Acetone 700 - 700 Benzene 1 5 1 Bromochloromethane - 10 (1 ) 10 Bromodichloromethane 1 100 (2) 1 Bromoform 4 100 (2) 4 Bromomethane 10 10 (1 ) 10 Carbon disulfide - - -Carbon tetrachloride 2 5 2 Chlorobenzene 4 100 4 Chloroethane - - -Chloroform 6 100(2) 6 Chloromethane 30 3 (1) 3 cis-1 ,2-Dichloroethene 10 70 10 cis-1,3-Dichloropropene NA 10 (3) 10 Dibromochloromethane 10 100(2) 10 Ethylbenzene 700 700 700 Meth~ene chloride 2 5 2 Styrene 100 100 100 Tetrachloroethene 1 5 1 Toluene 1000 1000 1000 trans-1,2-Dichloroethene 100 100 100 trans-1,3-Dichloropropene NA 10 (3) 10 Trichloroethene 1 5 1 Vinyl chloride 5 2 2 Xylene (total) 40 10000 40

Notes: - NJ GWQS - New Jersey Groundwater Quality Standards (N.J.A.C. 7:9-6) listed value

represents higher of the practical quantitation level and groundwater quality criterion. - Federal MCl - Maximum contaminant levels as set forth in 40 CFR 141 and 143). - Data Evaluation Criterion represents the more stringent of the state and Federal standards. (1) Represents the lifetime Health Advisory. (2) Represents the MCl for total trihalomethanes. (3) Represents the Drinking Water Equivalent level.

tables.xls:gw vocs

Table 7 Groundwater Criteria for Metals

Parameter NJGWQS

(ug/l) Federal MCL

(ug/l)

Background Groundwater Quality (ugll) Data Evaluation Criterion (ugJl)MLCMS

Aauifer

Middle Wenonah AQuifer

Englishtown Aauifer

low high low high Aluminum 200 200(1l 1320 28200 136J 392 U 200 (*) Antimony 20 6 U 2.7J U 4.7J U 6 Arsenic 8 50 U 154 U U U 8 (*) Barium 2000 2000 81.5J 93J 58.8J 250 94.3J 2000 Beryllium 20 4 1.4J 4J 0.7J 1.1J U 4 Cadmium 4 5 0.79J 6.9 0.36J 1J U 4 (*) Calcium - - 3960J 25900 8500 33800 19000 -Chromium 100 100 12.5 338 1.6J 2J 1.4J 100 (*) Cobalt - - 8.7J 18.9J U 1.2J 0.7R -Copper 1000 1300 4.6J 25.2 U U U 1000 Iron 300 300 (1) 5210 135000 20100 49300 8560 300 (*) Lead 10 15 3.3 35.6 U 5 U 10 (*)

MaQnesium - - 5500 9430 1230J 5890 1750J -ManQanese 50 50 (1) 60.6 354 166 477 94.7 50 (*) Mercury 2 2 U U U U 0.13J 2 Nickel 100 - 17.1J 69.5 U 2J U 100 Potassium - - 2000J 14700 2490 13700 7870 -Selenium 50 50 U 10.7R U 3.2R U 50 Silver NA 100 (1) U U U U U 100

Sodium 50000 - 1490J 8260J 4700 7680 5160 50000

Thallium 10 2 U U U 3.5J U 2 (*)

Vanadium - - 4.2J 287 U 1.7J 2.1J -Zinc 5000 5000 (1) 87 309 6.5J 17j 20J 5000

Notes: - NJ GWQS - New Jersey Groundwater Quality Standards (N.J.A.C. 7:9-6) listed value

represents higher of the practical quantitation level and groundwater quality criterion. - Federal MCl - Maximum contaminant levels as set forth in 40 CFR 141 and 143). - Data Evaluation Criterion represents the more stringent of the state and Federal standards. (1) Represents Secondary Drinking Water Standards, which are unenforceable guidelines regarding taste. odor and color of drinking water. (*) Data evaluation criterion is less than background concentrations, data will be assessed on a case by case basis. U =Not detected above the reported quantitation limit J =analyte positively Identified. concentration is approximate R =data rejected by data validator

Background Wells: MLCMS aquifer. LDS-1(R). LDS-202. LDS-3

Middle Wenonah aquifer: LDM-1 (R). LOM-2, LDM-203

Englishtown aquifer: LOE-202 (LDE-1 could not be sampled due to broken casing)

tables.xls:gw metals

Table 8 Groundwater Criteria for General Parameters

Parameter Units NJGWQS

(mg/l) Federal MCl

(mg/l)

Background Groundwater Quality (mg/ll Data

Evaluation Criterion (mgtl)

MlCMS Aquifer Middle Wenonah

Aquifer Englishtown

Aquifer low hig-h low high

Alkalinity, Total mg/l · · U 7.2 14.8 57 53 . BOD, 5 Day mg/l · · U U U 5.3 6.1 -.Chemical Oxygen Demand mg/l - · U U U U U Chloride mg/l 250 250 (if U 49 U 41 U 250 DO (Hach) mg/l · · 4.5 10.7 0 0.8 0 -FE+2 (Hach) mg/l - · 0 11 2.6 4.6 2.6 -Hardness, Total mg/l 250 · 57.7 74.5 36.5 119 93.6 250 NitrOQen, Ammonia mg/l 0.5 · U U U U U 0.5 Nitrogen, Nitrate mg/l 10 10 U 7.3 U 480 U 10 (0)

NitrOQen, Nitrate + Nitrite mgll 10 10 U 7.3 U 823 U 10 (0)

Nitrogen, Nitrite mg/l 1 1 U U U 0.01 0.01 1 ORP mV · · 197 342 -103 26 ·101 -£H standard - · 4.29 4.69 5.G9 6.9 7.66 -Phenols mg/l 4000 · U U U 0.057 U 4000 Solids, Total Dissolved mg/l 500 500(1) 63 199 153 293 95 500 Specific Conductance mS/m - - 16 22 24 59 21 -Sulfate mg/l 250 250 (1) U 37.9 34.6 103 16.1 250 Temperature deg.C - - 14.5 22.6 16.4 19.4 14.7 -Total Organic Carbon mg/l - - U 7.9 U 1.3 1.1 -

Notes: - NJ GWQS - New Jersey Groundwater Quality Standards (N.J.A.C. 7:9-6) listed value

represents higher of the practical quantitation level and groundwater quality criterion. - Federal MCl • Maximum contaminant levels as set forth in 40 CFR 141 and 143). - Data Evaluation Criterion represents the more stringent of the state and Federal standards. (1) Represents Secondary Drinking Water Standards, which are unenforceable guidelines regarding taste, odor and color. (*) Data evaluation criterion is less than background concentrations, data will be assessed on a case by case basis.

U =not detected above the reported sample quantitation limit

Background Wells: MlCMS aquifer: LDS-1(R), lDS-202, LDS-3 Middle Wenonah aquifer: LDM-1(R), LDM-2, LDM-203 Englishtown aquifer: lDE-202 (lDE-1 could not be sampled due to broken casing)

tables.xls:gw general

APPENDIX I

ADMINISTRATIVE RECORD INDEX

Landfill & Development Company Site Administrative Record

• Superfund Record ofDecision, Landfill and Development Superfund Site (NJDEP, September, 2004)

• Board of Chosen Freeholders Letter from William S. Haines, Jr., Freeholder to Dr. Judith Shaw, Manager, NJDEP, September 8, 2004

• Board of Chosen Freeholders Letter from William S. Haines, Jr., Freeholder to Dr. Judith Shaw, Manager, NJDEP, June 23,2004

• Notice ofPublic Meeting, Courier Post, May 20,2004, page14B

• Notice of Public Meeting, Burlington County Times, May 17,2004, page A7

• Superfund Proposed Plan, Landfill and Development Superfund Site (NJDEP, May, 2004)

• Revised Feasibility Study Report (GeoTrans, August 8, 2001) (referred to as the FS Report)

• Revised Human Health Risk Assessment (GeoTrans, May 16,2001)

• Revised Ecological Risk Assessment Report (HSI GeoTrans, April 18, 2000, plus Addendum dated December 15,2000)

• Revised Ground Water Remedial Investigation and ORC Pilot Test Report (HSI GeoTrans, June 12, 2000) (referred to as the RI Report)

• Updated Well Survey Report (HSI GeoTrans, December 29, 1999)

• Phase 11 Remedial Investigation Addendum Report, Landfill and Development (L&D) Company Site, Mount Holly, New Jersey (GeoSyntec, September 1995)

• Certification ofLandfill Closure, letter from Mr. John A. Castner, Chief, Bureau of Landfill Engineering (NJDEP) to Mr. Thomas J. Jennings ofL&D, May 24, 1995

• Final Gas System, Leachate Collection System, and Capping System Certification, Landfill and Development Co, Inc. (L&D), Mt. Holly, New Jersey (Langan, November 1994)

• Phase II Remedial InvestigationlFeasibility Study Report, Landfill and Development (L&D) Company Site, Mount Holly, New Jersey, Part 1, Remedial

Investigation Report (GeoSyntec, January 1994)

• Final Draft, Phase II Remedial InvestigationlFeasibility Study, Landfill and Development (L&D) Company Site, Mount Holly, New Jersey, Part III, Feasibility Study Report (GeoSyntec, September 1993)

• Phase II Remedial InvestigationlFeasibility Study Report, Landfill and Development (L&D) Company Site, Mount Holly, New Jersey, Part II, Baseline Risk Assessment Report (GeoSyntec, August 1993)

• Administrative Consent Order II, July 1990

• Soil Gas Survey, Landfill and Development Landfill, Mt. Holly, New Jersey (Roy F. Weston, April 1989)

• Phase I Sampling Report, L&D Site RIfFS, Mt. Holly, New Jersey (BakerfTSA, July 1988)

• Administrative Consent Order, January 1988

• Interim Background Investigation, L&D Site RIfFS, Mount Holly, New Jersey (BakerfTSA, March 1987)

• Hydrogeologic Investigation and Assessment, L&D Landfill, Mt. Holly, New Jersey (Fred C. Hart Associates, Inc., January 1986)

• Hydrogeologic Investigation in the Vicinity o/the L&D Landfill, Burlington County, New Jersey (Geraghty & Miller, Inc., November 1983)

• Groundwater Withdrawal Project, Report ofAnticipated Aquifer Response (Wehran Engineering, April 1977)

• Investigation ofSoil and Conditions, Sanitary Landfill, Mt. Holly, New Jersey, for Landfill and Development Company (Dames & Moore, October 1973)

• Letter from Jacqueline E. Schafer, USEPA Regional Administrator to Senator Frank R. Lautenberg, August 17, 1983

• Letter from Senator Frank R. Lautenberg to USEP A Congressional Relations Office, June 24, 1983

APPENDIX II

EPA LETTER OF CONCURRENCE

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 2

290 BROADWAY NEW YORK, NY 10007-1866 .

Joseph Seebode, Assistant Commissioner Site Remediation New Jersey Department of Environmental Protection 401 East State Street, P.O. Box 402 Trenton, New Jersey 08625-0402

Dear Mr. Seebode:

The United States Environmental Protection Agency, Region 2, (EPA) has reviewed the Record of Decision (ROD) for the Landfill and Development Company (L&D) Site located in Mount Holly and Eastampton Townships, Burlington County, New Jersey.

EPA concurs with the selected remedy presented in this ROD, Alternative 3, Landfill Management, Enhanced Aerobic Treatment of Cell 9, Ground Water Extraction (Central Area) and Recirculation into Landfill. The remedy also calls for installation of an alternative water supply for certain residences, unless Burlington Coun-ty shows positive steps toward acquiring the impacted properties within six months of the signing of the ROD. EPA's concurrence is based on the determination that the selected remedy will provide the highest degree of long-term effectiveness and permanence and the highest degree of overall protection to human health and the environment compared to the other alternatives, and the existence of a contingency for extracted water to be sent to a publicly owned treatment works should conditions indicate that the aerobic treatment technology is no longer effective.

EPA looks forward to working with your staff on this site.

Sincerely,

OV"/..fI.---George Pavlou, Director Emergency and Remedial Response Division

Internet Address (URL) • http://www.epa.gov Recycled/Recyclable • Printed with Vegetable 011 Based Inks on 100% Postconsumer, Process Chlorine Free Recycled Paper

APPENDIX III

RESPONSIVENESS SUMMARY

Responsiveness Summary

This responsiveness summary is divided into the following sections:

A. Overview B. Background on Community Involvement and Concerns C. Summary of Comments Received during the Public Comment Period and NJDEP

responses.

A. Overview

This is a summary of the comments and questions from the public regarding the Proposed Plan, dated May 2004, for remediation of the ground water at the Landfill & Development (L&D) Superfund Site, and the New Jersey Department of Environmental Protection's (NJDEP) and U.S. Environmental Protection Agency's (USEPA) responses to those comments and questions.

A public comment period was held from May 20,2004 through July 21,2004 to provide interested parties the opportunity to comment on the Proposed Plan for the L&D site. During the comment period, the NJDEP held a public meeting on May 24, 2004 at 7:00 PM at the Burlington County Human Services Building to discuss results of the Remedial Investigation and Feasibility Study (RI/FS) reports and to present the NJDEPIUSEPA preferred alternative for remediation of the site. NJDEP also attended a meeting on July 15, 2004 with members of the Rancocas Creek Association to discuss these items.

The selected alternative includes enhanced treatment of a portion of the landfill in conjunction with ground water extraction in the Central Area. The Proposed Plan's suite of remedial alternatives were developed for remediation of the site in accordance with the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA), as amended, and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).

B. Background on Community Involvement and Concerns

There has been a great deal of community involvement in the L&D site over the years. Many of the concerns go back to the mid-70's when sampling by Burlington County Health Department first indicated contamination in several of the private wells in the area. The site received attention from area residents, municipal, state, county and federal officials as well as the media. In 1984 Senator Hart visited the site as part of his presidential campaign. Concerned residents petitioned Senator Lautenberg to take action on the site.

A primary concern of the community has always been the ground water contamination. Residents also voiced concerns about offensive odors. The Rancocas Creek Association

has been involved with the site for many years. Other issues of concern have focused on the potential environmental and public health risks posed by the site.

C. Summary of Comments Received during the Public Comment Period and NJDEPfUSEPA responses

Proposed Treatment

COMMENT 1:

Will the extra ground water extracted (up to 30 gallons/minute or 50,000 gals/day) put a strain on the Mount Holly Sewage Authority (MHSA)? Will it need to raise rates to accommodate the extra flow?

RESPONSE 1:

No, for the first two years the ground water is going to be re-injected back into the landfill. Following those two years, the ground water will be sent to the MHSA. At that point we expect the quantity that needs to be sent to the MHSA to diminish.. L&D has spoken with the MHSA to ensure they have adequate capacity. The amount this project contributes is minimal compared to the authority's overall capacity.

COMMENT 2:

Why do you discuss a five-year timeline for the proposed remedial action?

RESPONSE 2:

We based that on what has been seen at other sites, also taking into account the levels of contaminants we see here. We expect two years of active treatment and then we are estimating another three years of natural attenuation and extraction of leachate that will be sent to the treatment plant.

COMMENT 3:

Would you look at options four and five if the treatment was not working?

RESPONSE 3:

We may, but first we would likely install additional extraction wells, continue extraction and off-site disposal of the leachate to the MHSA. Problems with the selected remedy can be addressed through the mandatory five-year review that will be conducted by NJDEP.

COMMENT 4:

The installation and use of the ground water recirculation system has the potential to release VOCs, besides methane and other odor causing agents. No holes or trenches into the contents of the landfill should be left open overnight during the installation or use of the leachate recirculation system in order to minimize odors. Please define the monitoring plan for the atmosphere near cell 9, and let those living close to this operation know of the plan.

RESPONSE 4:

L&D will monitor the air at the work site for particulates and all contaminants of concern and will take all necessary steps to minimize odors, including covering holes and trenches if necessary. The detailed air monitoring plan will be placed in the document repository once it is developed.

COMMENTS:

Will the community be given the opportunity to review and comment on the specific remediation plan design?

RESPONSES:

We will notify those that attended the public meetings that the design is available for review at the repository (Burlington County Public Library). We can hold a public meeting to discuss the design if it is desired.

COMMENT 6:

It was requested that results of monitoring wells be made easily available to those affected. Specifically, it was requested that any property owner within 1000 ft. of a test site that does not meet water quality standards be notified of the test result.

RESPONSE 6:

We are not equipped to furnish results on a broad and continuing basis like this. We will respond to individual requests for information. We also can put the information in the repository and investigate making it available electronically.

COMMENT 7:

The Proposed Plan focuses on Cell #9. How do we know other portions of the landfill won't be problems later on?

RESPONSE 7:

Over the last several years we have seen diminishing levels of contamination outside of the Central Area. The conditions in the landfill are relatively stable and we do not expect significant deterioration to occur. There will be long-term monitoring of the ground water.

Water Line

COMMENT 8:

What is the role of Green Acres in the waterline process?

RESPONSE 8:

Burlington County already purchased properties in the area through the use of Green Acres funds. Any significant change of use of these properties (such as running a water line through them) requires a variance from the Green Acres program.

COMMENT 9:

What if Green Acres says no to the variances?

RESPONSE 9:

L&D would need to look at other options to provide potable water to residences on Rabbit Run.

COMMENT 10:

Please keep us up to date on the Green Acres process.

RESPONSE 10:

We will contact the Rancocas Creek Association as requested.

COMMENT 11:

What is the purpose of the access agreements and when will we see them?

RESPONSE 11:

An access agreement must be signed by the property owners to allow the water line to be installed. Most of the agreements are already signed. L&D Company will be in contact with those property owners who have not signed agreements in the near future.

COMMENT 12:

When is installation of water line anticipated to start?

RESPONSE 12:

If the County provides written documentation to NJDEP by March 30, 2005 that the properties along Rabbit Run and Hand Lane will be acquired by March 2006, or otherwise satisfactorily demonstrate to NJDEP that it will acquire the properties in a reasonable time frame, then the water line will not be installed. If this documentation is not provided, then it should take approximately six to nine months after the March 30, 2005 County deadline for Green Acres to issue the variances for the water line. Water line construction should be completed six to nine months after Green Acres approval.

COMMENT 13:

It is the view of Burlington County that acquisition of the properties along Rabbit Run is the only means to address issues affecting the area. These issues include flooding, effects on water quality from septic systems and open space preservation. Burlington County has requested DEP to reconsider installation of the water line on Rabbit Run and Hand Lane in order to allow for Burlington County to initiate acquisition of the properties.

RESPONSE 13:

We can defer the implementation of the water line for six months pending the timely initiation of the purchase process by the county. Details regarding this extension are included in the ROD.

COMMENT 14:

All residences in there area should be connected to public water supply.

RESPONSE 14:

Many residents in the vicinity of the landfill are already connected to a municipal water line. The remaining residents within the area potentially impacted by the landfill will be connected by the water line extension.

Private Wells

COMMENT 15:

What is meant by the decommissioning of wells? Will private wells still be allowed for agricultural use?

RESPONSE 15:

As part of the overall project of installing waterlines the municipality may decide to no longer allow wells used for non-potable purposes. In that case, those wells would need to be sealed once homes are connected to public water supplies. The municipality will make this decision.

COMMENT 16:

The proposed plan calls for a temporary or perhaps permanent use restriction on private wells in the entire area. The function of this plan is supposed to be to return the ground water to New Jersey drinking water quality standards. Therefore, any water use restrictions should be specific to use for human consumption, they should be temporary and should be specific to wells into the Wenonah aquifer only. In addition if NJDEP notifies local government of contamination in the wells and recommends usage restrictions, it should take responsibility to follow this action by again notifying those government bodies when the water quality has been improved and recommend the restrictions be lifted.

RESPONSE 16:

Wells are typically sealed to avoid situations where residents are knowingly or unknowingly using their water for potable purposes. It is difficult to ensure water is not used for potable purposes when changes are made at transfer of ownership. It is possible in this instance that the restriction is only put in place on use of the upper two aquifers.

COMMENT 17:

The water from my well turns my laundry and dishes orange. There also is a concern that it may be causing infections.

RESPONSE 17:

The orange color most likely comes from the elevated iron in the ground water and surface water in the area. It is recommended that the owner test their well for coliform bacteria to look for an indication ofharmful bacteria in the water.

Rancocas Creek

COMMENT 18:

Are toxic wastes going in the creek?

RESPONSE 18:

While there is a general flow of ground water into the creek and there are elevated levels of contaminants in the Central Area, the ground water around the bulk of the landfill is continuing to improve. Contaminant levels in the creek are within acceptable risk ranges. In addition, if contaminants reach the creek, the amount of water that is in the creek would provide significant dilution of contaminant levels, and volatile organic chemicals (VOCs) would be able to volatilize to the atmosphere.

COMMENT 19:

Who is testing the creek? Should it be tested on a regular basis?

RESPONSE 19:

There was sampling of the surface water and sediments done a few years ago as part of the Remedial Investigation and Risk Assessment by L&D. At the request of the public, additional confirmatory sampling of the creek (surface water) will occur in October 2004. We do not see the need to sample the sediments again since the risk assessment showed there was no increased risk from the sediments.

COMMENT 20:

Are my children at risk from swimming in the creek?

RESPONSE 20:

The Risk Assessment showed that the landfill is not causing or adding to any risks associated with the creek. Please note though, that there could be potential concerns for swimmers if weather conditions or malfunctioning septic systems in the area cause high fecal coliform counts in the creek.

COMMENT 21:

Does L&D have the responsibility to test the creek periodically and advise residents of the condition of the water? .

RESPONSE 21:

If there was an unacceptable risk from an exposure in the creek due to the landfill we would have required that. Based on this request we have asked L&D to sample the creek. They will do that in October 2004. That is generally a time of year when the flow in the creek is low and we feel that the sampling would best represent any contribution of contaminants coming from the landfill. We will evaluate those results to determine whether any additional sampling is necessary.

COMMENT 22:

Are there conditions under which the flow of ground water or contaminants will increase which would necessitate additional testing of the creek?

RESPONSE 22:

We have sampled the monitoring wells regularly for the past several years and we see the general decrease in contaminant levels. We do not anticipate any dramatic changes from those results. The remedy is designed to continue to reduce the flow of contaminants to the creek.

Surface Water

COMMENT 23:

Are there any breaches of the clay barrier that would affect the surface water runoff?

RESPONSE 23:

No. As part of the general surface water permit issued to L&D, the site is inspected on a semi-annual basis. They have to maintain vegetation and deal with any erosion problems.

COMMENT 24:

There are problems with the detention basin being loaded with silt and orange water and running across roads and properties towards the creek and the canal. The canal isn't moving at all, it's a mosquito trap.

RESPONSE 24:

NJDEP will require that L&D address the discharge from the site. Regarding the concern about mosquitoes in the canal, the Burlington County Mosquito Control can be contacted to address this issue at P.O. Box 6000, 49 Rancocas Road, Mt. Holly, NJ 08060. Their phone number is (609) 265-5064.

COMMENT 25:

The discharge from the retention basin (northcentral) goes into a creek and washes out Shreve Street where the creek crosses the road.

RESPONSE 25:

NJDEP, along with L&D, will ensure this problem is resolved.

Land Use

COMMENT 26:

Will Burlington County be attempting to acquire the landfill?

RESPONSE 26:

We are not aware of any action of that sort.

COMMENT 27:

Will the landfill be usable for other purposes?

RESPONSE 27:

That determination will be made when the reinjection system is operational and its effectiveness is monitored.

COMMENT 28: Who is bearing the cost of the remediation effort?

RESPONSE 28:

The L&D Company will pay for the remedy as well as the operation and maintenance costs.