The 131-acre North Sea Municipal Landfill site is an active landfill that is owned and operated by the Town of Southampton in Suffolk County, New York. In 1963, a landfill was constructed for the disposal of municipal solid waste, refuse, debris, and septic system wastes from residential, industrial, and commercial sources. There are three main landfill areas: a 13 acre area encompassing Cell No. 1 and related septic sludge lagoons, which received septic system sludge in the early 1960's in addition to municipal solid waste; Cell No. 2, which is 7 acres in size and was closed in 1990; and Cell No. 3, which is currently active, and accepts 80,000 tons of municipal waste annually. A ground water monitoring program, which has been conducted by the Town of Southampton since 1979, revealed a large ground water plume containing heavy metals that was migrating from Cell No. 1 toward Fish Cove. A 1989 ROD addressed onsite source contamination as OU1 and provided for capping Cell No. 1 to reduce the potential threat to human health and the environment by reducing the risk of contaminant migration. The ROD addresses onsite ground water, as OU2. Studies conducted during the risk assessment for OU2 confirmed that the risks to human health are within EPA's acceptable risk range.