The South Municipal Wellfield Superfund Site is situated in southern New Hampshire in the Town of Peterborough. The Site includes the 24-acre New Hampshire Ball Bearings, Inc. (NHBB) manufacturing facility, the now closed South Municipal Water Supply Well, and surrounding upland and wetland habitat. The NHBB facility has operated as a ball bearing manufacturing plant since its construction in 1957. The primary contaminants of concern at the Site are those used in the manufacture of ball bearings. They include volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). Contaminants are known to have been discharged to the exterior of the plant via floor drains and direct disposal activities. Elevated levels of VOCs were detected in water samples from a well, several surface water bodies in the area, and surface soils. Sediments from a wetland and small brook were contaminated with PCBs, PARs and localized accumulations of heavy metals. Approximately one acre of wetland sediments contained PCBs and PAHs above cleanup levels. These wetlands provide habitat for migratory birds.