An ecological risk assessment for Portsmouth Naval Shipyard, Kittery, Maine

An ecological risk assessment was conducted to assess the ecological risk of hazardous waste releases from the Portsmouth Naval Shipyard located on Seavey Island in the Piscataqua River and Great Bay Estuary, New Hampshire and Maine. Problem formulation suggested that certain areas in the lower estuary had the highest potential for impact, particularly depositional areas where fine-grained sediment particles accumulate. Lead, mercury, copper, zinc, nickel, arsenic, and to a lesser degree PCBs, PAHs, silver and cadmium were identified as contaminants of concern based on their spatial distribution in the estuary, hazard quotient screening levels for sediments and surface water, links to primary sources, and releases of contaminants and ecological damage from Shipyard Solid Waste Management Units. Ecological risk characterization was conducted for exposure pathways and receptors using measurement endpoints to assess risks to pelagic species, epibenthic species, benthic community, salt marsh community, eelgrass community, herbivorous waterfowl, avian predators, and trophic transfer of contaminants through the food chain. The results suggested that ecological risk was related to the loss of habitat from direct disposal of hazardous material in tidal flats, and heavy metal exposure and potential impact on ecological receptors associated with benthic, epibenthic, saltmarsh, and eelgrass habitats located in depositional areas around Seavey Island