The Site is an area of groundwater contamination that covers approximately 400 acres in Cinnaminson and Delran Townships in Burlington County, New Jersey. It includes properties bounded by Union Landing Road, US Route 130, River Road and Taylors Lane, as well as properties outside these boundaries where contaminants may have migrated or threaten to migrate. The Site consists of a landfill, residential properties, and light to heavy industrial properties. Unlined slurry pits and cooling ponds are located on one industrial property. The landfill portion of the Site originally began as a sand and gravel mining pit. During the late 1950s, municipal solid wastes were deposited in the completely unlined mining pits, while mining operations continued in other parts of the property until the late 1960s. After the mines were closed, large amounts of refuse and solid waste were deposited in the pits. Municipal and institutional wastes, bulky wastes, vegetable and food processing wastes, and industrial wastes, including hazardous substances were deposited into two areas of the landfill. In 1980, operations ceased. A clay cap was installed over the landfill to restrict rain and surface water from infiltrating into the wastes, thus reducing the amount of contaminated liquid flowing from the Site and entering the groundwater. The underlying aquifer is a source of drinking water for people living around the Site. There are both public and private water supply wells within one mile of the Site; however, the private wells are not being used for drinking water. Approximately 55,000 people live within a three mile radius of the Site.
Since the early 1980s, private parties under Administrative Orders issued by the New Jersey Department of Environmental Protection (NJDEP) and EPA have conducted hydrogeological and soil investigations associated with historical disposal practices of the former landfill and several industrial properties that comprise the area-wide groundwater contamination. These investigations were conducted to determine the nature and extent of site-related contaminants. In addition to identifying volatile organic compound (VOC) contamination in the groundwater beneath the Site, the investigations confirmed the presence of chlorinated VOCs, primarily TCE and PCE in soil and groundwater. Groundwater contamination was discovered by NJDEP through the review of groundwater monitoring data collected as part of the closure plan for the landfill in the early 1980s. Contaminants including, but not limited to, vinyl chloride, 1,2-dichloroethane (1,2-DCA), PCE, TCE, cis-1,2-dichloroethene (cis-1,2-DCE), benzene and arsenic were found in the groundwater and soil.
EPA included the Site on the NPL in June 1986.
EPA began an investigation of the groundwater contamination during a Remedial Investigation/Feasibility Study (RI/FS) that was completed in 1989. The investigation included the installation of monitoring wells and sampling of the groundwater around the Site to locate the areas of greatest contamination. The hydrology at the Site is complicated by the presence of discontinuous clay layers, or lenses, beneath the Site that tend to create a shallow aquifer above the deep aquifer. Both the shallow and the deep aquifers were found to be contaminated. In 1990, EPA developed and evaluated the alternatives for remediation of the groundwater contamination at the Site.
Remediation of the Site is being addressed in three operable units. The first operable unit, OU-1, is ongoing and is directed at the cleanup of the groundwater contamination from the landfill at the Site. EPA is addressing OU-1 by pumping the groundwater, treating it to remove the contaminants, and re-injecting the treated groundwater into a deep underground layer of water. The second operable unit, OU-2, is ongoing and will address the effectiveness of the clay cap in reducing the generation of leachate. The third operable unit, OU-3, is currently in progress with an RI/FS being performed by a private party pursuant to an Administrative Settlement Agreement and Order on Consent entered into between EPA and that party. OU-3 addresses certain light to heavy industrial properties on the northwestern part of the Site, at which historic disposal and operational practices have resulted in soil and groundwater contamination.
In conjunction with the RI/FS being implemented as part of OU-3, EPA determined the need to perform a vapor intrusion investigation. Four rounds of vapor intrusion investigations at the Site, conducted by NJRB, revealed that vapors from VOCs, including TCE and PCE associated with contaminated groundwater at the Site, are present in the sub-slab soil gas and indoor air of residential properties at the Site.
