portsmouth naval shipyard


The Portsmouth Naval Shipyard (PNS) is located on a 278-acre site, two-thirds of which is covered by a high-density industrial area, containing 376 buildings. The shipyard is built on Dennet's, Seavey's, Jamaica, and Clark's Islands, connected by 90 acres of fill. This filling of the tidal flats gradually took place as the space needs of PNS increased. Shipbuilding at the site started in 1690 and PNS became a Navy shipyard in 1800. Ships and submarines have been constructed at PNS, currently the shipyard is used to overhaul nuclear powered attack submarines. PNS consists of three dry docks, 6,500 linear feet of berthing, and 376 buildings and other structures. Hazardous wastes have been stored, disposed of, spilled, or treated at more than 30 acres on the site. From 1945 to 1975, untreated acidic and alkaline wastes, waste battery acid and lead sludge, wastewater and spent baths from an electroplating operation, and other wastes from various industrial shops were discharged into the Piscataqua River via industrial waste outfalls. From 1945 until approximately 1978, 25 acres of tidal flats between two of the islands were filled with wastes including chromium-, lead-, and cadmium-plating sludge; asbestos insulation; volatile organic compounds (VOCs); waste paint and solvents; mercury-contaminated materials; sandblasting grit containing various metal wastes; and dredged sediments from the Piscataqua River. In the late 1970s, dredged sediment samples collected near the industrial outfalls were found to be contaminated with elevated concentrations of metals, polychlorinated biphenyls (PCBs), and other contaminants. The Navy has indicated that the probable source of the sediment contamination is the industrial outfalls at PNS. Groundwater supplies drinking water to 10,000 people within 4 miles of the site. However, groundwater beneath the PNS (the island) is not hydraulically connected to the groundwater that supplies drinking water. The mainland on both sides of the river in the immediate vicinity is a thickly settled residential area with commercial/light industrial land use activities.

Hazardous Ranking Score

50 / 100

A score of 28.5 or higher qualifies a site for the Superfund National Priority List.

Regional Contact

Region 1
Phone: (888) 372-7341
Fax: (617) 918-0101

Outside New England:
(617) 918-1111

Contact Region



Site Inspection
Preliminary Assessment
Final Listing On NPL

Contaminants & Health Effects

      Endocrine Disrupter
      Reproductive Toxin
      Persistent, bioaccumulative and toxic


        African American
        American Indian and Alaska Native
        Native Hawaiian


        People living
        within a 1 mile radius


        Average Income


        Occupied homes

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