GLOUCESTER TOWNSHIP, NJ
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The GEMS Landfill site is located in Gloucester Township, New Jersey, and covers approximately 60 acres. It is located near the intersection of New Brooklyn-Erial and Turnersville-Hickstown Roads, and rises approximately 100 feet above the surrounding terrain. The eastern edge of the landfill is bordered by a stream called Holly Run, which flows into Briar Lake a quarter mile away from the site.
The site was used as a landfill by a series of operators, starting with the Township, which has owned the parcel since the 1950s. Information collected by EPA and the New Jersey Department of Environmental Protection (NJDEP) showed that municipal and industrial wastes were routinely disposed of at the site from 1969 to 1980. The landfill was last operated by Gloucester Environmental Management Services, Inc. (GEMS) until it was closed by NJDEP in 1980.
EPA placed the site on the Superfund program’s National Priorities List in September 1983, and a plan to address the site contamination was selected in 1985. The majority of the site’s cleanup activities were completed in 2004, and long-term cleanup operation and maintenance (O&M) is ongoing.
What Has Been Done to Clean Up the Site?
In 1980, NJDEP began testing groundwater from private water wells in the area, as well as surface water from Holly Run and Briar Lake, for the presence of volatile organic compounds (VOCs). The sampling confirmed that elevated concentrations of VOCs were present in both the groundwater and surface water. Residents were urged to connect to public water systems and the State restricted installation of new wells in the affected area by establishing a classification exception area (CEA) to prevent new water supply wells from being drilled. In 1983, EPA removed debris from the site and constructed a fence, two culverts and a berm to prevent residents from coming into contact with wastes at the site and control drainage from the site. The site was placed on the Superfund program’s National Priorities List in September 1983.
In 1983, EPA removed debris from the site and put in a partial fence, two culverts and a berm to prevent residents from coming in contact with wastes in the area and to control drainage from the site.
On September 27, 1985, EPA issued a Record of Decision that selected the remedial action components as noted in the above section entitled “EPA’s Involvement in the Site.” Most cleanup activities were completed in August 1994.
In March 1985, EPA completed a remedial investigation of the nature and extent of contamination at the site. This included hydrogeologic and geophysical investigations to determine groundwater quality, flow and aquifer characteristics; sampling and testing of air, landfill gases, surface water, soil and sediment; and studies of the liquids that percolate through the landfill (leachate). The investigation showed that groundwater, soil, landfill gas, surface water and sediment were contaminated with volatile organic compounds (VOCs) and heavy metals, including arsenic, barium and lead. In addition, leachate was found to contain trace concentrations of pesticides. Based on these results and other findings from the investigation, EPA and NJDEP announced a selected cleanup plan in September 1985, which called mainly for capping of the landfill, and extracting and treating contaminated groundwater. The treated water was to be discharged to either a publicly owned treatment works (POTW) or to Holly Run. This long-term action was subsequently divided into Phases I and II.
Phase I activities began in 1989 and were conducted by the GEMS Trust under an agreement with the state of New Jersey. The activities included regrading the landfill slopes and placing a cap on the landfill; installation of a leachate collection system and an underdrain in Holly Run; construction of a gas collection and treatment system; installation of drainage controls; cleanup of the Holly Run stream and nearby Briar Lake; and the connection of potentially affected residences to the existing municipal water supply system. Work was completed in 1994 and served to substantially reduce the amount of leachate generated and hazards posed by landfill gases.
The GEMS Trust regularly inspected the Phase I remedy to ensure that the fence was maintained, and that there were no issues with the landfill cap and landfill gas collection and treatment system. Improvements and repairs occurred as needed, and NJDEP now continues these activities as part of the long-term O&M of the site.
Phase II of the remedial action was initiated in June 1997, when EPA and the state of New Jersey reached a settlement with private parties to pay for past costs associated with the site, and to perform the Phase II activities. This phase consisted of the design and construction of a groundwater extraction and on-site pre-treatment system. During the design, a publicly owned treatment works (POTW), the Camden County Municipal Utilities Authority (CCMUA) wastewater treatment plant, was selected as the discharge option. At the time of construction, the system included a series of eight extraction wells along the northwestern boundary of the landfill to pump contaminated water from the aquifer, and a new pump station and force main to convey collected groundwater from the Holly Run underdrain to the pre-treatment plant. There, the water would undergo physical and chemical treatment for the removal of landfill contaminants. After the final treatment step, the treated groundwater would be pumped to a holding tank where it was to be discharged to the CCMUA for final treatment.
Construction of the GEMS treatment system was completed in April 1999, and startup was scheduled for June 1999. However, prior to startup, the CCMUA issued a cease discharge notice in connection with the potential discharge of radionuclides. A subsequent radionuclide groundwater investigation concluded that radionuclides in groundwater monitoring wells were due to naturally occurring sources. The system eventually began operation in summer 2005 and has been operating since that time. Groundwater monitoring is conducted on a semi-annual basis and reported annually.
Several additional actions were completed and/or are ongoing subsequent to completion of the Phase 2 activities. In 2008, a vapor intrusion study was completed, which indicated that the concentrations of VOCs were below EPA’s groundwater screening concentrations. In 2014, a deep horizontal well was installed to the north/northwest of the landfill to better capture the groundwater plume at the downgradient end of the plume. Also in 2014, the GEMS Trust installed five additional off-site sentinel wells to assess the continued appropriateness of the CEA boundary. Monitoring of the swamp pink population, a federally listed threatened and endangered plant species that was identified in the wetlands surrounding the landfill during the initial site investigations, continues to assure the plant is not being adversely affected by the remedy.
A review of the remedy conducted in 2014 identified the need for a baseline ecological risk assessment. A screening level ecological risk assessment completed in 2010 concluded that additional site-specific information was needed to fully understand any potential impacts to the ecological community at the site. Potential risks to ecological receptors were evaluated in an Ecological Risk Assessment Step 3 Report March 2015. The report concluded that no further ecological risk assessments are required. Comments on this report from NJDEP and EPA stated that there may be potential risk of arsenic to benthic communities in Briar Lake, and further sediment sampling is warranted. In January 2017, NJDEP conducted additional sediment sampling. Based on results of this sampling and the report it was concluded that a baseline ecological risk assessment was not required.
The fourth Five Year Review of the site was completed in 2019. It concluded that the remedy is currently protective of human health and the environment, and that monitoring and additional investigation should occur to assure it remains so.
What Is the Current Site Status?
EPA and NJDEP approved the GEMS Trust Certification Report indicating that groundwater containment had been achieved within the specific boundaries identified in the 1997 consent decree. Therefore, consistent with the consent decree, O&M activities were transferred to NJDEP in July 2015. EPA and NJDEP continue to review data to ensure that the remedy operates as intended.
NJDEP is working with Gloucester Township (with EPA’s assistance) for posting deed notices both on the landfill property and five adjacent residential properties where components of the remedy are located and which are within the limits of the CEA established for contaminated groundwater at the site.