Bangor Naval Submarine Base covers about 7,000 acres near Silverdale, Washington. It operated as a munitions storage and processing facility from the early 1940s until 1973, then was recommissioned in 1977 to support the Trident submarine fleet. The site was placed on the National Priorities List (NPL) in 1990, and cleanup work began in 1993. In 2004, the base merged with Naval Station Bremerton to form Naval Base Kitsap, now the third-largest Navy base in the country.
Past detonation, demilitarization, and disposal of explosive ordnance left behind a wide range of contaminants. Groundwater, soil, surface water, and sediment are all affected. Contaminants include TNT, RDX, dinitrotoluene (DNT), benzene, toluene, chlorinated solvents such as 1,1-dichloroethene and 1,2-dichloroethane, polychlorinated biphenyls (PCBs), heavy metals like lead, arsenic, and cadmium, polycyclic aromatic compounds, DDT, and dioxin. A 1994 gasoline tank overflow in the Public Works Industrial Area released 20,000 gallons and contaminated nearby residential drinking water wells with volatile organic compounds (VOCs). The Navy connected affected residents to municipal water by autumn 1995.
The site is divided into ten operable units (OUs), each targeting a specific area or contamination problem. Cleanup methods include groundwater extraction and treatment, soil excavation, composting, engineered caps, monitored natural attenuation, and free product recovery. A granulated activated carbon groundwater treatment system at Site F has been running since 1994. Major construction across all units was completed between 1993 and 2001. The EPA determined that human exposure is not currently under control and that contaminated groundwater movement has not been stabilized, so monitoring and active treatment continue. A feasibility study for Site F is expected to finish between December 2027 and February 2028. A separate remedial investigation into per- and polyfluoroalkyl substances (PFAS) began on December 18, 2025, with a feasibility study estimated for the same timeframe.
The most recent five-year review was completed on September 29, 2025. Five-year reviews verify that cleanup actions remain protective of human health and the environment. The site has not been deleted from the NPL and has not yet achieved sitewide ready for anticipated reuse status, meaning cleanup goals have not been fully met for all land uses across the base.
Community members can participate in the cleanup process by submitting comments or concerns. The Naval Facilities Engineering Systems Command Northwest Public Affairs Office accepts input by phone at (360) 340-5592 or by email at navfacnwpao@us.navy.mil. Site documents are available at several locations, including Kitsap Regional Library in Bremerton and Kitsap County Public Utility District in Poulsbo. The EPA Remedial Project Manager and Community Involvement Coordinator can also help direct the public to relevant records.
