SECOND FIVE-YEAR REVIEW REPORTLANDFILL & DEVELOPMENT COMPANY SUPERFUND SITE

BURLINGTON COUNTY, NEW JERSEY

Prepared by

u.s. Environmental Protection AgencyRegion 2

New York, New York

July 2016

Date:

Walter E. Mugdan, DirectorEmergency and Remedial Response Division

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Table of Contents

Executive Summary ..................................................................................................................... iv 

Five-Year Review Summary Form ............................................................................................. v 

Introduction ................................................................................................................................... 1 

Site Chronology ............................................................................................................................. 1 

Background ................................................................................................................................... 1 

Physical Characteristics ..................................................................................................... 1 

Site Geology/Hydrogeology ................................................................................................ 1 

Surface Water Features ...................................................................................................... 2 

Land and Resource Use ...................................................................................................... 2 

History of Contamination ................................................................................................... 3 

Initial Response ................................................................................................................... 3 

Basis for Taking Action ....................................................................................................... 3 

Remedial Actions .......................................................................................................................... 4 

Remedy Selection ................................................................................................................ 4 

Remedy Implementation ...................................................................................................... 6 

System Operations/Operation and Maintenance ................................................................ 7 

Progress Since Last Five-Year Review ....................................................................................... 8 

Five-Year Review Process ............................................................................................................ 8 

Administrative Components ................................................................................................ 8 

Community Involvement ...................................................................................................... 9 

Document Review ................................................................................................................ 9 

Data Review ........................................................................................................................ 9 

Site Inspection ................................................................................................................... 11 

Interviews .......................................................................................................................... 11 

Institutional Controls Verification .................................................................................... 12 

Technical Assessment ................................................................................................................. 12 

Question A: Is the remedy functioning as intended by the decision documents? ............. 12 

Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives used at the time of the remedy still valid?............................................. 14 

Question C: Has any other information come to light that could call into question the protectiveness of the remedy? ........................................................................................... 15 

Technical Assessment Summary ....................................................................................... 15 

Issues, Recommendations and Follow-Up Actions .................................................................. 15 

Protectiveness Statement ............................................................................................................ 15 

Next Review ................................................................................................................................. 15 

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Tables ........................................................................................................................................... 16 

Table 1 Chronology of Site Events................................................................................... 16 

Table 2a: Remediation Goals for Soil (all concentrations in μg/kg) ............................... 17 

Table 2b: Remediation Goals for Groundwater (all concentrations in µg/L) ................. 17 

Table 3: Documents, Data and Information Reviewed in Completing the Five-Year Review ............................................................................................................................... 18 

Attachments ................................................................................................................................. 19 

Figure 1 ............................................................................................................................. 19 

Figure 2 ............................................................................................................................. 20 

Figure 3 ............................................................................................................................. 21 

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Executive Summary

This is the second five-year review for the Landfill & Development Superfund Site located in the Townships of Mount Holly, Eastampton, and Lumberton, Burlington County, New Jersey. The purpose of this five-year review is to review information to determine if the remedy is and will continue to be protective of human health and the environment. The triggering action for this statutory five-year review is the completion date of the previous FYR, July 18, 2011. This second five year review found that the implemented remedy is protective of human health and the environment.

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Five-Year Review Summary Form

Issues/Recommendations

OU(s) without Issues/Recommendations Identified in the Five-Year Review:

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SITE IDENTIFICATION

Site Name: Landfill & Development Superfund Site

EPA ID: NJD 048044325

Region: 2 State: NJ City/County: Mt. Holly, Eastampton, and Lumberton, Burlington County

SITE STATUS

NPL Status: Final

Multiple OUs? No

Has the site achieved construction completion? Yes

REVIEW STATUS

Lead agency: State [If “Other Federal Agency”, enter Agency name]:

Author name (Federal or State Project Manager): Douglas Tomchuk, RPM

Author affiliation: USEPA Region 2

Review period: 09/09/2015 - 6/13/2016

Date of site inspection: 10/30/2015

Type of review: Statutory

Review number: 2

Triggering action date: 7/18/2011

Due date (five years after triggering action date): 7/18/2016

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Protectiveness Statement(s)

Operable Unit: OU1

Protectiveness Determination: Protective

Addendum Due Date (if applicable):

Protectiveness Statement: The remedy at L&D landfill is protective of human health and the environment.

Sitewide Protectiveness Statement

Protectiveness Determination: Protective

Addendum Due Date (if applicable):

Protectiveness Statement: The site remedy is protective of human health and the environment.

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Introduction The purpose of a five-year review is to evaluate the implementation and performance of a remedy in order to determine if the remedy is and will continue to be protective of human health and the environment and is functioning as intended by the decision documents. The methods, findings, and conclusions of reviews are documented in the five-year review. In addition, five-year review reports identify issues found during the review, if any, and document recommendations to address them. This is the second five-year review for the Landfill & Development Superfund site, located in the Townships of Mount Holly, Eastampton, and Lumberton, Burlington County, New Jersey. This five-year review was conducted by the Environmental Protection Agency (EPA) Remedial Project Manager (RPM) Douglas Tomchuk. The review was conducted pursuant to Section 121(c) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, 42 U.S.C. §9601 et seq. and 40 CFR 300.430(f)(4)(ii), and in accordance with the Comprehensive Five-Year Review Guidance, OSWER Directive 9355.7-03B-P (June 2001). This report will become part of the site file. The triggering action for this statutory review is the completion date of the previous five-year review. A five-year review is required at this site due to the fact that hazardous substances, pollutants or contaminants remain at the site above levels that allow for unlimited use and unrestricted exposure. The site consists of one operable unit, which is addressed in this five-year review. Site Chronology See Table 1 for the site chronology. Background

Physical Characteristics The Landfill & Development Company Site is a closed landfill located in Burlington County, New Jersey. It occupies portions of the Townships of Mount Holly, Eastampton, and Lumberton. The site is located on the north side of Route 38 and is approximately 200 acres in size. 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, and a landfill gas management system. The North Branch of Rancocas Creek (hereafter referred to as Rancocas Creek) is located approximately 700 feet north of the landfill boundary. (See Figure 1). In 2015, a solar power farm was built on approximately 50 acres of the eastern portion of the landfill. Approximately 42,000 solar panels were erected on the surface of the cap.

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 (see Figure 1): • Mount Laurel/Cape May Sand (MLCMS) aquifer

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• Upper Wenonah confining unit • Middle Wenonah aquifer • Marshalltown/Lower Wenonah confining unit, and • Englishtown aquifer. Groundwater flow in all three aquifers is northward, towards Rancocas Creek. 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. Groundwater also discharges seasonally as groundwater 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).

Portions of the MLCMS aquifer and Middle Wenonah aquifer have been impacted by the landfill. Groundwater in the underlying Englishtown aquifer has not been impacted by the landfill. The greatest concentrations of contaminants in groundwater are found in the Middle Wenonah aquifer in a relatively narrow band downgradient of the eastern portion of the Mount Holly section. This relatively narrow band of higher concentrations is referred to as the “Central Area.” Only the Central Area of the Middle Wenonah aquifer is associated with unacceptable levels of risk. Based on a comparison of historical groundwater levels versus the bottom elevation of landfill contents, groundwater 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 groundwater to be periodically in contact with the refuse. Groundwater use in the vicinity of the L&D Site is restricted through a Classification Exception Area (CEA) that NJDEP established on May 23, 2008. The CEA restricts use of the upper aquifers under the site, extending to Rancocas Creek, but does allow use of the uncontaminated Englishtown aquifer. (See Figure 3.)

Surface Water Features There are also several surface water features in the vicinity of the site. 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 runoff collection system that includes five sedimentation ponds. There are some locations between the landfill and Rancocas Creek where groundwater seasonally discharges to land surface (referred to as "groundwater seeps"). These features should not be confused with seeps of liquid leaching from the landfill itself (referred to as “leachate seeps”) which are not present. During wet periods, numerous groundwater seeps have been observed between the landfill and Rancocas Creek, some with standing water and others flowing. However, during dry periods, the groundwater seeps are not present.

Land and Resource Use

To the north of the L&D Site, there are first a number of commercial properties, followed by several residential properties and then an area of open space (designated Green Acres property)

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and Rancocas Creek. To the east are residential properties, and to the west are residential properties and a county children’s home. To the south is a combination of commercial/retail properties and farmland. (Please see Figure 2.) Groundwater use in the vicinity of the L&D Site is restricted through a Classification Exception Area (CEA) that NJDEP established on May 23, 2008. The CEA restricts use of the upper aquifers under the site, extending to Rancocas Creek, but does allow use of the uncontaminated Englishtown aquifer. (See Figure 3.) There were no federally listed or proposed threatened or endangered species found at the site.

History of Contamination The site operated as a sand and gravel pit from the early 1940s until approximately 1968. The first waste disposal activities at the site are believed to have been initiated in 1962, when the property owner began disposing of demolition debris in the Mount Holly section of the landfill. The disposal of demolition debris occurred from 1962 until the late 1960s. During this time period, a 10-foot thick layer of refuse was deposited on what is believed to have been the excavated base of the sand and gravel pit. In 1968, the owner 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 (the L&D Company, currently a subsidiary of Waste Management, Inc.) acquired the property in 1971, and began landfilling operations in the Eastampton section of the site in 1976. These operations continued until 1981.

Initial Response

The 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; and A clay cover system.

Residents downgradient of the landfill using private wells were provided with bottled water by L&D Company to ensure that they were not potentially exposed to contaminants originating from the site.

Basis for Taking Action The site was included on the National Priorities List (NPL) in 1983. A Remedial Investigation and Feasibility Study (RI/FS) was initiated by NJDEP in 1986. In 1988, the L&D Company signed an Administrative Order on Consent which included, among other things, completion of

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the RI/FS. NJDEP selected a remedy for the site and a Record of Decision (ROD) was issued in 2004. The groundwater investigations at the site found that the shallow aquifers (the Mount Laurel/Cape May Sands, and the Middle Wenonah) were contaminated with volatile organic compounds (VOCs) from the site. VOCs found at the site included: 1,2-dichloroethene, 2-butanone, 4-methyl-2-pentanone, acetone, benzene, cis-1,2-dichloroethene, methylene chloride, toluene, and vinyl chloride. Elevated metals concentrations are found in groundwater at background wells, and in some cases background groundwater quality exceeds groundwater quality criteria (e.g., aluminum, arsenic, cadmium, chromium, iron, lead, manganese, and thallium), for total and/or dissolved metals. However, sampling results indicate that for some inorganic parameters (including metals) the landfill is causing impacts to groundwater quality, while for other inorganic parameters it is difficult to determine if the landfill is causing impacts to groundwater. Inorganic parameters impacted by the landfill at one or more wells include chloride, hardness, ammonia, total dissolved solids (TDS), iron, lead, manganese, and sodium. Inorganic parameters that may or may not be impacted by the landfill include aluminum, arsenic, cadmium, and thallium. The cumulative carcinogenic risk from exposure to groundwater 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 have been identified as risk drivers; that is, the risk from exposure through all evaluated pathways exceeds the upper bound of EPA's acceptable level of 1 x 10-4 due to arsenic, l,2-dichloroethane, benzene, methylene chloride, and vinyl chloride. The noncarcinogenic hazard index (HI) from exposure to contaminants in the groundwater of the Central Area of the Middle Wenonah aquifer through ingestion, inhalation, and dermal contact is a HI of 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 Hazard Quotient (HQ) for each of these chemicals exceeds the EPA benchmark of 1. An ecological risk assessment was conducted and 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. Therefore, no action for surface water or sediment was warranted at the site. Remedial Actions

Remedy Selection A Superfund Record of Decision was issued by NJDEP, with EPA concurrence, on September 30, 2004. For the landfill contents, the primary remedial action objective are to maintain the existing engineering controls that accomplish the following:

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Prevent direct contact with landfill contents; Reduce leaching of constituents to groundwater over time; Control surface water runoff and erosion; and Control landfill gas migration.

A secondary remedial action objective for landfill contents was to reduce the mass, toxicity, or mobility of potentially hazardous constituents in Cell 9. For groundwater, remedial action objectives are to:

Prevent human consumption of groundwater from the MLCMS and Middle Wenonah aquifers between the landfill and Rancocas Creek;

Achieve remediation goals established for groundwater in the MLCMS and Middle Wenonah aquifers; and

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

The ROD identified the selected remedy for the site and included:

Construction and operation of a groundwater 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 groundwater would be recirculated into the landfill along with appropriate air injection to enhance contaminant degradation. Excess water would be discharged to the POTW (publicly owned treatment works) for treatment if necessary;

Long-term monitoring for groundwater exceeding the remediation 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, Implementation of a Classification Exception Area, and; Continued maintenance of the site security.

The ROD also included:

Burlington County should continue the process of acquiring properties along Rabbit Run and Hand Lane because:

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.

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The ROD also specified that if the County did not provide written documentation to NJDEP from the Board of Chosen Freeholders of Burlington County within 6 months that the properties would be acquired, or otherwise satisfactorily demonstrate to NJDEP that it would acquire the properties in a reasonable timeframe, the following remedy would also be implemented:

Water line extension to Hand Lane and along the western portion of Rabbit

Run, downgradient of the landfill.

Several of the property owners sold their properties to Burlington County, after several extensions to the time frame to install the water line. On September 3, 2009, an Explanation of Significant Differences (ESD) was issued by EPA involving the residential water supply components of the remedy. The ESD indicated that future water supply to residences on Hand Lane and the western portion of Rabbit Run would be provided by the installation of a new residential water supply well at each of the remaining properties not owned by Burlington County. The water supply wells would be installed in the Englishtown aquifer, which is not impacted by the landfill and not restricted for use by the CEA. Any existing water supply wells on those properties would be decommissioned. The new water supply wells would be in lieu of the public water line extension identified in the ROD.

Remedy Implementation The Remedial Action Work Plan (RAWP), dated January 26, 2006, provided details regarding the remedy design. It also included the rationale and criteria for when certain aspects of the remedy can be discontinued, (e.g., recirculation of groundwater into Cell 9). The RAWP was approved by NJDEP on June 23, 2006, subject to four conditions that the L&D Company agreed to implement during the construction and post-construction phases (by letter dated July 3, 2006). Installation of extraction wells and associated piezometers began in July 2006. The installation of the groundwater recirculation and air injection piping and equipment began in October 2006. Continuous operation of groundwater extraction with recirculation of extracted water (plus leachate at times) began on February 27, 2007. The air injection phase of the remedy was tested in November 2007, and had intermittent operation during a shakedown period between November 30 and December 10, 2007, at which time more continuous operation of the air circulation was initiated. The air system then operated over a period of approximately 3.5 months. On April 2, 2008, air recirculation was discontinued due to subsurface combustion of waste near air injection well AI-2S. In August 2008, additional air monitoring points were added via direct push technology, and based on temperature and carbon monoxide readings in the vicinity of AI-2S, some subsurface smoldering of waste was still occurring in that area. When tested in December 2009, the VOC levels in the landfill seemed to be reduced in comparison to the concentrations measured when the system was operating for an extended period of time in 2008. The testing results indicated either: (1) there were less VOCs in Cell 9 than in the initial phase of the remedy, as a result of the remedy; or (2) the air system may need to operate longer than the several weeks tested in December 2009 to get enough circulation and

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temperature increase to yield the higher VOCs. In order to attempt to determine which circumstance was more likely, the L&D Company conducted a longer-term air system test in Fall 2010. It was determined that continuing operation of the aeration system would provide limited additional benefit when compared with the cost of system operation. No further operation of the air recirculation system was conducted. Injection of extracted groundwater in Cell 9 was stopped in July 2011. In the ROD, groundwater extraction was anticipated to continue for three years after the aerobic treatment was discontinued to achieve the Remediation Goals in the Middle Wenonah aquifer. The groundwater extraction system is in the process of a phased shut down. Shut down activities are anticipated to be complete in 2018. The residential water supply components of the remedy (installation of new residential wells and decommissioning of existing wells) were addressed in a RAWP Addendum. The RAWP Addendum was approved by NJDEP in a letter dated July 29, 2009. Several of the residents on Hand Lane and Rabbit Run sold their properties to Burlington County, and those properties are included in the area designated as Green Acres property. By early 2010, it was clear that three residents would not be selling to the County, so permanent drinking water supply wells were installed for those residences in February 2010. One remaining property had a new well installed and tested in August 2010, bringing the total to four. These wells were installed by the L&D Company, with oversight from NJDEP. The wells draw water from the Englishtown Aquifer, which is not affected by the site. Therefore, the alternative water supply component of the remedy is completed. Bottled water had been supplied to residents potentially impacted by the landfill from before the ROD was issued. Now that acceptable water is available to all remaining residents, it is no longer necessary for the L&D Company to provide bottled water to the residents. The landfill property and areas downgradient of the landfill, but still south of Rancocas Creek were designated a Classification Exception Area by NJDEP on May 23, 2008. The CEA does not include the Englishtown Aquifer. CEA Biennial Certifications have been completed since then, with the latest submitted on May 23, 2016. The CEA will continue until groundwater quality standards are achieved. The long-term monitoring program, which began in May 2006, continues to be implemented in accordance with the schedule in the document entitled, “Long-Term Monitoring: Locations and Frequency” (dated April 15, 2005 plus addendum dated January 16, 2006). This plan includes both the Central Area as well as the Flank Areas.

System Operations/Operation and Maintenance The L&D Company operates the groundwater and leachate recovery systems as part of its landfill closure permit. Collected leachate is sent to the local sewage treatment plant for disposal. Landfill gas is collected and flared (methane recovery was discontinued prior to issuance of the ROD because it was no longer economically viable). Groundwater circulation into the landfill was discontinued in July 2011. All groundwater extraction wells have been shut down, with the shut-down test for RW-1 continuing through 2018. The L&D Company continues to conduct long-term monitoring in accordance with the approved Long Term Groundwater Monitoring (LTM) Plan. As part of the LTM, wells are sampled at intervals established in the plan, based on

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the well location. The landfill closure permit requirements continue to be implemented. Site fencing is maintained, the cap inspected and mowed, and the leachate collection system checked. Several flow meters and associated piping have required replacement due to corrosion. One major change to the site is the installation of a large solar farm on the eastern portion of the landfill. Approximately 42,000 solar panels were installed by PSE&G and are currently operational, generating approximately 13 MW of electricity. The L&D Company (currently a subsidiary of Waste Management, Inc.) reviewed the plans and conducted oversight of the installation to ensure that the integrity of the landfill cap will be maintained. Potential site impacts from climate change have been assessed, and performance of the remedy is currently not at risk due to the expected effects of climate change in the region and near the site. Progress Since Last Five-Year Review Protectiveness statement(s) from previous FYR: Because the remedial actions at the L&D

Company Site are protective, the site is protective of human health and the environment. The landfill is capped and fenced, hydraulic containment has been established, and new water supply wells have been installed and screened in an aquifer not affected by the site for the remaining downgradient residences. Institutional controls are in place in the form of the approved landfill closure plan and the groundwater Classification Exception Area established by NJDEP. These controls will need to remain in place until contaminant concentrations in groundwater meet the appropriate criteria.

Recommendations identified in previous FYR: The report did not identify any issues or

recommend any action at this site needed to protect public health and/or the environment. Other suggestions: The following activities should continue in accordance with the existing

plans because metal concentrations remain above cleanup standards: • landfill leachate collection, monitoring and disposal; • process monitoring at a monthly frequency; • implementing the LTM program at the current frequency; and, completing the shut-down test for RW-1.

As recommended in the previous FYR, the LTM Plan should be reviewed to ensure that the data being collected are sufficient to determine whether aquifer restoration (i.e., contaminant concentrations at or below NJGWQS or MCLs) can be achieved. If NJGWQS or MCLs cannot be attained after implementation of the groundwater remedy, then the ROD calls for issuance of TI waivers, through an ESD.

Groundwater extraction is no longer being conducted, with the trial period scheduled to last until the end of 2018.

Five-Year Review Process

Administrative Components

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The five-year review team included Doug Tomchuk, EPA-RPM), Ed Modica (EPA-Hydrologist), Abbey States (EPA-Human Health Risk Assessor), Mindy Pensak (EPA-Ecological Risk Assessor) and Wanda Ayala (EPA-Community Involvement Coordinator). This is a PRP, State-lead site.

Community Involvement On November 19, 2015, EPA Region 2 posted a notice on its website indicating that it would be reviewing site cleanups and remedies at 32 Superfund sites and four federal facilities in New York and New Jersey, including the Landfill and Development Company Superfund site. The announcement can be found at the following web address: http://www2.epa.gov/sites/production/files/2015-11/documents/fy_16_fyr_public_website_summary.pdf. Local officials were informed of this by the Community Involvement Coordinator. In addition to this notification, Waste Management was notified that EPA would be conducting a five-year review. Once the five-year review is completed, the results will be made available at the local site repository, which is at the Burlington County Library, 5 Pioneer Boulevard, Westampton, NJ 08060.

Document Review The documents, data and information which were reviewed in completing this five-year review are summarized in Table 3.

Data Review Groundwater data has been collected regularly at the site for process monitoring of the groundwater extraction system and as part of the long-term monitoring plan. These data have been reported in Remedial Action Progress Reports and the last round of data submitted was included the Remedial Action Report #25 dated January 27, 2016. Based on process performance data, the extraction system performed as designed, effectively containing dissolved phase VOCs and preventing downgradient migration. Historically, all recovery wells operated at close to target rates of 6 gallons per minute (gpm) per well. As of September 4, 2015 all extraction wells were shut down due to persistently low VOC concentrations. The shut-down test for RW-1 will continue through the end of 2018. As a result of groundwater extraction, contaminants downgradient of the central area in the Middle Wenonah and MLCMS aquifer monitoring wells have decreased substantially (see Figure 3 for well locations). For example, in well LDM-206, methylene chloride was detected at 1,200 micrograms per liter (µg/L) in 2005, was reduced to 38 µg/L in late 2007, and has been non-detect since. Benzene was detected at 110 µg/L in 2006 but has decreased to 3.7 µg/L in the latest sampling event (11/6/15). This concentration is still above the New Jersey Ground Water Quality Standard (NJGWQS) of 1 µg/L, but below the Federal Maximum Contaminant Level (MCL) of 5 µg/L. Also at LDM-206, 1,2-DCA was detected at 1,500 µg/L in 2006 but decreased to 4.2 µg/L in November 2015. In the MLCMS aquifer, benzene and chlorobenzene continue to exceed NJGWQS and MCLs, but are limited to the immediate vicinity of the landfill boundary. Historically, the centrally located recovery wells RW-2 and RW-4 have had the highest VOC concentrations whereas recovery wells at the edges, RW-1 and RW-3, have had much lower

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VOC concentrations. Since 2007, concentrations of acetone, 2-butanone, 4-methyl-2-pentanone, 1-2-DCA, benzene, and methylene chloride have declined to various degrees. Extraction well RW-2 was shut down on March 2009 due to persistently low VOC concentrations. Similarly, extraction wells RW-4 and RW-3 were shut down in February 2012 and August 2012, respectively. The wells will remain in stand-by/shut-down mode unless "trigger concentrations" are observed either in these extraction wells or in the monitoring wells LDM-306, LDM-307, and LDM-308 (these wells were installed between the extraction wells and are used to augment concentration data from the location of the extraction wells). Thus, as part of the shut-down test, NJDEP would be notified if 1,2-DCA reached 20 µg/L or benzene reached 35 µg/L at RW-2 or at nearby monitoring well LDM-306; 1,2-DCA reached 20 µg/L or benzene reached 50 µg/L at RW-4 or LDM-308; and 1,2-DCA reached 20 µg/L or benzene reached 50 µg/L or vinyl chloride reached 20 µg/L at RW-3 or LDM-307. In the MLCMS aquifer (shallow), concentrations exceeding criteria are limited to benzene and chlorobenzene, which, in turn, are limited to the immediate vicinity of the landfill boundary (wells 12S and LDS-205). Criteria are not exceeded for any VOCs north of the immediate landfill boundary (25S, LDS-206, LDS-8, and LDS-208). There are currently higher concentrations of benzene and chlorobenzene observed at LDS-205 (see Figure 3 for LTM well locations) compared to before the remedy, presumably related to the flushing of Cell 9 associated with the remedy. It is likely that the groundwater in the vicinity of LDS-205 was captured by nearby extraction well RW-1R (which is screened deeper), and it is also noted that both benzene and chlorobenzene are non-detect at LDS-206 which is located further downgradient. In the Middle Wenonah aquifer, there have been significant concentration reductions for VOCs in the Central Area since prior to the remedy and at the time of the RI sampling in 1999. At LDM-206, concentrations are currently non-detect for most VOCs and only slightly above criteria for 1,2-DCA (4.2 µg/L) and benzene (3.7 µg/L) as of November 2015, whereas prior to the remedy there were multiple VOCs with concentrations greater than 1,000 µg/L. These much lower VOC concentrations at LDM-206 are attributed to the successful hydraulic capture of the most impacted groundwater that is provided by the remedy extraction. Concentration reductions have also been noted at LDM-7 (1,2-DCA, benzene, and vinyl chloride have been reduced to 4 µg/L, 1.3 µg/L, and 3.5 µg/L, respectively as of November 2015 ). 1,4-Dioxane has been reported as a tentatively identified compound in several samples at LDM-301 at levels that exceed the NJDEP Interim Groundwater Quality Criteria. At LDM-210, located less than 400 feet down-gradient of RW-1, there have been significant reductions of most VOCs, such as MEK, acetone, MIBK, and toluene. However, there continue to be relatively stable concentrations of 1,2-DCA (at concentrations ranging from 5.1 µg/L to 29 µg/L for sampling events between May 2010 and November 2015) and benzene (at concentrations ranging from 15 µg/L to 44 µg/L for same period), which are the only two VOCs exceeding criteria at this well. These are the same constituents observed at the two outer recovery well locations (RW-2 and RW-4) and these concentrations of 1,2-DCA and benzene may reflect the general concentration of the "relatively clean" groundwater at the edges of the remedy capture zone. The other constituents are within the capture zone of the remedy and/or have been sufficiently remediated within the landfill. The concentrations of 1,2-DCA and benzene observed at LDM-210 attenuate significantly by the time the groundwater reaches LDM-206, about 250 feet downgradient of well LDM-210 (currently less than 5 µg/L for each constituent).

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At well 22M, located just upgradient of extraction well RW-1, there has also been a very substantial decline in VOC concentrations for many constituents such as MEK and methylene chloride. Because this is upgradient of the extraction well, these concentration declines indicate reduced source strength beneath the landfill. This is likely due to the remedy, but is also due to declining source strength over time due to natural degradation within the landfill that was already occurring prior to the remedy. The most significant VOC concentrations remaining at this well are 1,2-DCA, which ranged from 1.8 µg/L to 65 µg/L for sampling events between May 2010 and November 2015, and benzene, which ranged from 6.3 µg/L to 83 µg/L for the same period. In the Middle Wenonah aquifer, the concentration patterns in the Flank Areas (see Figure 3 for well locations in the Flank Areas) are similar to those prior to the remedy and at the time of the RI sampling in 1999. There are minor exceedances of just a few VOC parameters. In the Englishtown aquifer, no VOCs exceed criteria, and no VOCs have been detected over the course of the remedy (similar to historic results). Groundwater remains impacted above criteria for metals. Various concentrations of iron, manganese, sodium, aluminum, and arsenic (both total and dissolved) have been reported at levels above standards. As stated in the ROD, there are background concentrations for some metals which exceed criteria, and the landfill may add to these impacts. The presence of elevated metals and other inorganics is addressed by the remedy, via groundwater use restrictions in the CEA. As was suggested in the 2011 five year review, the Long-Term Monitoring Plan should be reviewed to ensure that the data being collected are sufficient to determine whether aquifer restoration (i.e., contaminant concentrations at or below NJGWQS or MCLs) can be achieved. If NJGWQS or MCLs cannot be attained, then the ROD calls for issuance of Technical Impracticability (TI) waivers, through an ESD. Leachate and landfill gas collection and monitoring has continued under the landfill closure plan. Management of the landfill closure is being conducted by NJDEP Bureau of Solid Waste.

Site Inspection The inspection of the site was conducted on October 30, 2015. In attendance were Doug Tomchuk, EPA; Will Reilly, EPA-ORC, and Chad Moose of Waste Management. The emphasis of the site inspection involved the installation of the solar energy array on the eastern portion of the landfill. At the same time EPA was able to observe site conditions to support this five year review.

Interviews During the five-year review process, interviews were conducted with Waste Management and NJDEP staff. The purpose of the interviews was to document any perceived problems or successes with the remedy that has been implemented to date. Interviews were conducted on October 30, 2015 and on June 14 and 15, 2016. Interviews are summarized below.

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Chad Moose, Waste Management October 30, 2015 at site. Chad provided a tour of the site, with a focus on the ongoing installation of the solar power farm. A press event was held on site by Public Service Electric & Gas (PSE&G) to inform people of the progress on the installation. Chad Moose, Waste Management and Rob Greenwald, Tetratech June 14, 2016, phone No major issues with respect to the five year review. The groundwater extraction system proved to be successful and all recovery wells have now been shut down. The shut-down test for RW-1 will continue through the end of 2018. The solar power installation has been very successful. Ross Hull, NJDEP Solid Waste Management June 15, 2016, phone. Ross indicated that there had been some increasing methane concentrations along the southern perimeter of the landfill. Waste Management has been working with the NJDEP solid waste program to report gas concentrations and will continue to monitor levels. Future monitoring/collection/flaring of the methane will need to be determined. This issue is being handled by the Landfill Closure Permit and is not specifically a concern with respect to hazardous waste issues. Gwen Zervas, NJDEP Site Remediation Program June 15, 2016, phone. Gwen had no specific concerns regarding the five year review, and would coordinate with NJDEP Solid Waste Management staff as necessary regarding closure issues.

Institutional Controls Verification Institutional controls are in place in the form of the approved landfill closure plan and the groundwater Classification Exception Area established by NJDEP. These controls will need to remain in place until contaminant concentrations in groundwater meet the appropriate criteria.

Technical Assessment

Question A: Is the remedy functioning as intended by the decision documents? All components of the groundwater remedy for the L&D Landfill Superfund Site were installed, were operated and functioned as intended by the decision documents resulting in the current shut down testing of the system. According to the 2004 ROD, the major components of the remedy include construction of a groundwater extraction system, construction of enhanced aerobic treatment, long-term monitoring in the central and flank areas of the landfill, maintenance of existing cover, continued landfill leachate and gas monitoring, collection and disposal, maintenance of site security, and decommissioning of residential water-supply wells (and public water line extension) downgradient of the landfill.

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The Groundwater Extraction/Recirculation component of the remedy was intended to provide hydraulic containment of dissolved phase VOCs was constructed in July of 2006 and put into operation by late February 2007. Between March 2009 and September 2015, wells RW-2, RW-4, RW-3 and RW-1 were progressively shut down due to persistently low VOC concentrations. These wells will remain shut-down and on stand-by unless "trigger concentrations" of 1,2-DCA, benzene, or vinyl chloride (as established during the shut-down tests) are observed either in these extraction wells or in the monitoring wells LDM-306, LDM-307,and LDM-308 (wells installed between the extraction wells and used to augment concentration data from the location of the extraction wells). The Enhanced Aerobic Treatment component of the remedy included air injection and groundwater/leachate recirculation to stimulate biodegradation of waste in the source area and enhance contaminant mass reduction in the landfill. The construction of the air-recirculation system began July 2006 and was operated between December 2007 and April 2008. Based on an analysis showing limited additional benefit from the system, the air injection was terminated. Leachate collection continues to operate. The residential water supply component of the remedy was modified, through the September 2009 ESD, such that residents on Hand Lane and the western part of Rabbit Run were provided new residential water supply by the installation of wells at remaining properties not owned by Burlington County. Four wells were installed, one at Hand Lane and three on Rabbit Run. Installation of the last well was completed in July 2010. Two residential wells on Hand Lane and Rabbit Run were identified for decommissioning. The wells were properly abandoned and sealed in place in June of 2010. The Long-Term Groundwater Monitoring Program was initiated in May 2006. Monitoring wells are screened in the Mount Laurel/Cape May Sands (MLCMS), Middle Wenonah, and Englishtown aquifers and are sampled at different frequencies, according to the aquifer. In general, results from most recent groundwater sampling (November 2014) show that monitoring wells in Flank Areas show VOC concentrations that are substantially lower than the center. There are some exceedances of 1,2-DCA, benzene, and chlorobenzene reported in wells in the MLCMS and Middle Wenonah aquifers in the Flank Areas, although still located on the landfill property. There were no exceedances reported for wells screened in the Englishtown aquifer. Additionally, groundwater remains impacted above criteria for metals and other inorganics. It is recommended that the LTM Plan should be reviewed to ensure that the data being collected are sufficient to determine whether aquifer restoration (i.e., contaminant concentrations at or below NJGWQS or MCLs) can be achieved. Other structural components of the remedy appear to be regularly maintained and functional. Although some subsidence was noted on inspection, the condition of the landfill cover appeared to be in good repair and well maintained. Additional monitoring of the integrity of the cap is being conducted in the area of the solar panel installation. The gas monitoring and leachate collection systems are functioning and are well maintained. The fence that encloses the landfill is in good repair; if any fence sections are occasionally breached or vandalized, they are promptly repaired. Every effort should be made to minimize trespassing for the purpose of preserving the integrity of the cover system.

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NJDEP issued a Classification Exemption Area in 2008 to restrict groundwater use in the vicinity of the site between the landfill and Rancocas Creek until groundwater standards are achieved. Groundwater remains impacted above criteria for metals and limited VOCs in this area. The CEA applies vertically to the shallowest aquifers (the MLCMS and the Wenonah), ensuring that uses of the aquifer are restricted until groundwater standards are achieved. A well survey was performed for other wells between the landfill and Rancocas Creek. All properties in the CEA area are either connected to public supply or have wells screened in the uncontaminated Englishtown aquifer for potable supply and confirmed that any existing wells screened in shallower aquifers are not used for potable purposes.

Question B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives used at the time of the remedy still valid? There have been no physical changes to the site that would adversely affect the protectiveness of the remedy. Land use assumptions, exposure assumptions and pathways, cleanup levels and remedial action objectives (RAOs) considered in the decision documents remain valid. Although specific parameters have changed since the time the risk assessment was completed, the process that was used remains valid. The landfill cover, fence, and continued maintenance of these barriers prevent direct contact with landfill contents and control surface water runoff and erosion. All residential wells in the affected aquifers have been decommissioned and the installation of new wells is restricted through a current CEA; these controls prevent human consumption of groundwater from contaminated aquifers in the area. The groundwater and leachate monitoring systems reduce leaching of constituents to groundwater and control landfill gas migration. 1,4-Dioxane has been reported as a tentatively identified compound in several samples in the Central Area at levels that exceed the NJDEP Interim Groundwater Quality Criteria. All groundwater monitoring data are compared to NJDEP's Ground Water Quality Standards (N.J.A.C. 7:9C). While some NJGWQS have been revised since the time of the human health risk assessment and the ROD, the selected remedy remains protective of human health. A comparison of maximum concentrations to risk-based screening numbers indicates that consumption of groundwater would present unacceptable cancer risks and non-cancer hazards to humans. However, the remedy effectively prevents residents from drinking groundwater affected by site-related contaminants. The potential for soil vapor intrusion is evaluated when site soils and/or groundwater are known or suspected to contain VOCs. A January 2004 evaluation of the potential for vapor intrusion in residences downgradient of the landfill found that the pathway was incomplete. This was based on the finding of a low level of one VOC in the shallow groundwater in the proximity of downgradient residences. The long-term monitoring data since the previous five-year review continues to show only low levels of VOCs in the shallow MLCMS aquifer, with maximum concentrations of 2.7 ug/L 1,2-dichloroethane and 61 ug/L benzene. These maximum concentrations fall within the acceptable carcinogenic risk range of 10-4 to 10-6, therefore, the vapor intrusion pathway is likely to remain incomplete and no specific monitoring for soil vapor intrusion is necessary. There are no ecological risk concerns at the site at this time.

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Question C: Has any other information come to light that could call into question the protectiveness of the remedy? No other information has come to light that could call into question the protectiveness of the remedy.

Technical Assessment Summary The remedy selected in the 2004 ROD, and modified as per the 2009 ESD have been effective in controlling exposure to contaminants and have reduced the contaminant levels remaining on site. Issues, Recommendations and Follow-Up Actions This report does not identify any issues or recommend any action at this site needed to protect public health and/or the environment. Because 1,4-Dioxane has been reported as a tentatively identified compound in several samples at the site, this parameter should be added to the list of VOCs that are monitored for at the site. The Long-Term Monitoring Plan should be reviewed to ensure that the data being collected are sufficient to determine whether aquifer restoration (i.e., contaminant concentrations at or below NJGWQS or MCLs) can be achieved. If NJGWQS or MCLs cannot be attained after implementation of the groundwater remedy, then the ROD calls for issuance of TI waivers, through an ESD. Protectiveness Statement

Protectiveness Statement(s)

Operable Unit: OU1

Protectiveness Determination: Protective

Addendum Due Date (if applicable):

Protectiveness Statement: The L&D remedy is protective of human health and the environment.

Sitewide Protectiveness Statement

Protectiveness Determination: Protective

Addendum Due Date (if applicable):

Protectiveness Statement: The site remedy is protective of human health and the environment.

Next Review

The next five-year review report for the Landfill & Development Company Superfund site is required five years from the completion date of this review.

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Tables

Table 1 ChronologyofSiteEvents

Event

Date

Sand and gravel pit operations at the site Early 1940s - 1968

George Pettinos began demolition debris disposal 1962

The landfill began accepting industrial and commercial solid waste and sewage sludge 1968

The Landfill and Development Company acquired the property 1971 The L&D Landfill Site was added to the National Priorities List (NPL) 1983

NJDEP provided funds to conduct an RI/FS May 30, 1986

Permitted capacity reached – stopped accepting waste December 31, 1986

L&D entered into an Administrative Order on Consent with NJDEP 1988

Constructed closure systems approved May 24, 1995

Proposed Plan issued May 20, 2004 Record of Decision issued Sept. 30, 2004 Remedial Action Work Plan Approved June 30, 2006 On-site construction started July 17, 2006 Classification Exception Area designated by NJDEP May 23, 2008

Explanation of Significant Differences for residential water supply issued

September 3, 2009

Remedial Action Work Plan Addendum (for water supply wells) approved July 29, 2009

Water supply wells installed Feb - August

2010

Preliminary Close-Out Report Issued by EPA Sept. 27, 2010

Site visit for Five-Year Review December 22, 2010

Remedial Action Report issued January 31,

2011 Remedial Action Report approved by NJDEP

May 25, 2011

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Event

Date

Concurrence on Remedial Action Report approval by EPA June 9, 2011

First Five Year Review Issued July 18, 2011

Water recirculation to Cell 9 shut down July 2011

Installation of Solar Farm on Eastern Portion of Site July 2015 to

December 2015

Shut down of GW Recovery System September 4,

2015

Site Visit for Five Year Review October 30,

2015

Table 2a

Table 2b

Table 2a: Remediation Goals for Soil (all concentrations in μg/kg) From the September 30, 2004 ROD

Contaminants of Concern Soil - Protection of Groundwater Human Health Risk Remediation Goals

cis-1,2-Dichloroethylene 500 - 500Tetrachloroethylene 1,000 100,000 1,000Trichloroethylene 500 - 500Vinyl chloride 500 - 500

Table 2b: Remediation Goals for Groundwater (all concentrations in µg/L) From the OU[#] ROD

Contaminants of Concern National Primary Drinking Water Standards (Federal

MCLs) Remediation Goals

cis-1,2-Dichloroethene 70 70 Tetrachloroethene 5 5 Trichloroethene 5 5 Vinyl chloride 2 2

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Table 3

Table 3: Documents, Data and Information Reviewed in Completing the Five-Year Review

Document Title, Author Submittal Date

L&D Remedial Action Progress Report 24, Tetra Tech January 28, 2015

L&D Remedial Action Progress Report 25, Tetra Tech January 27, 2016

L&D Classification Exception Area Biennial Certification Submittal May 23, 2016

PSE&G Press Release – “PSE&G Building It Largest Grid Connected Community Solar Project on Burlington County Landfill”

October 30, 2015

Record of Decision September 2004

Explanation of Significant Differences September 2009

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Attachments

Figure 1

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Figure 2

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Figure 3