The PSC Resources Superfund Site is situated in south-central Massachusetts in the town of Palmer, approximately 15 miles east of Springfield, Massachusetts. The three acre site is located in the 100-year floodplain of the Quaboag River. The site was originally utilized for bulk oil storage by Mobil Oil Corporation in the 1930s and 1940s. PSC Resources purchased the property in the early 1970s and began operating a waste oil refinery and solvent recovery plant on the site in 1974. The facility reclaimed drained oils and solvents, treated them with heat, and sold them as heavy fuel mixes, lube oil base stock, and road spray. Millions of gallons of waste were left behind in tanks and lagoons when the plant was abandoned in 1978. Contamination of the site occurred due to improper containment of solvents and oils, spills, and poor maintenance activities resulting in the contamination of soil, groundwater and adjacent wetlands by polychlorinated biphenyls (PCBs), volatile organic compounds (VOCs), and heavy metals. A major release of hazardous materials occurred in 1978 during a 4,000-gallon spill from the site's containment lagoon, impacting the adjacent wetlands. Evidence suggests that additional releases of hazardous materials to on-site soils and buildings occurred frequently throughout the period of operation of the facility. The Massachusetts Department of Environmental Protection (MassDEP) began emptying the tanks and disposing of hazardous wastes in 1979. In 1982, MassDEP requested assistance from the US Environmental Protection Agency (EPA), and the PSC Resources site was added to the Superfund Program's National Priorities List (NPL) in 1983. The specific contaminants of concern at the site include PCBs, VOCs, semi-volatile organic compounds (SVOCs), lead, and zinc. Groundwater was contaminated with VOCs and SVOCs, and soils were contaminated with elevated levels of SVOCs, VOCs, metals, and PCBs (in a limited area adjacent to a former tank storage area). Sediments in the adjacent wetlands were contaminated with polycyclic aromatic hydrocarbons (PAHs), lead and zinc. In the Quaboag River, water and sediments contained relatively low levels of SVOCs, PCBs, and metals.