The Old Navy Dump/Manchester Laboratory sits on 53 acres along the western shore of Clam Bay in Puget Sound, north of Manchester, Washington. The Navy used the property from the 1940s to the 1960s for submarine net and boat work, firefighter training, and waste disposal. Those activities left behind dioxins, petroleum hydrocarbons, polychlorinated biphenyls (PCBs), metals, and asbestos. Contamination reached soil, sediment, seep water, and shellfish in Clam Bay. The bay supports recreational shell fishing and provides habitat for bald eagles and chinook salmon, both federally threatened species.
EPA identified 11 contaminants of concern across multiple media. Key substances include 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in soil, PCBs in sediment and leachate, copper across multiple media, lead and zinc in sediment, and nickel in surface water and leachate. EPA determined these substances pose unacceptable risks to human health and the environment based on exposure pathways to people and wildlife.
The site was added to the National Priorities List on May 31, 1994. The U.S. Army Corps of Engineers carried out cleanup work between 1999 and 2001, including removing contaminated soil from the former firefighter training area, building a landfill cap and shoreline protection system, and placing clean sediment in nearshore areas. Construction was completed on September 30, 2002, and the site reached sitewide ready for anticipated reuse status on September 27, 2010. A temporary restriction on subsistence-level shellfish harvesting remains in place. EPA and the National Oceanic and Atmospheric Administration (NOAA) own portions of the property, with EPA managing the northern 17.5 acres and NOAA's National Marine Fisheries Service occupying the southern 22.5 acres.
Two sources give conflicting assessments of current protectiveness. The health and environment section states that human exposure is currently under control and that there are no unacceptable human exposure pathways at this time. The cleanup section and community section both state that the 2024 Five-Year Review found the site is not yet protective of people's health or the environment. Long-term monitoring of seeps, sediment, and shellfish tissue is ongoing to determine whether cleanup actions will be protective in the long term.
Community members with questions can contact the EPA Remedial Project Manager. The Community Involvement Coordinator is also available. Site records can be reviewed at the U.S. Army Corps of Engineers office in Seattle, Washington, or at the Manchester Community Library in Port Orchard, Washington.
