Naval Support Facility Dahlgren sits on 4,300 acres along the Potomac River, about 40 miles south of Washington, D.C. The facility has operated since 1918, focusing on research, development, testing, and evaluation of surface ship weaponry. It was added to the EPA's National Priorities List (NPL) in October 1992. Physical cleanup construction is not yet complete across the full site.
Historical operations contaminated soil, groundwater, sediment, and surface water at 76 individual areas within the facility. Contaminants include metals such as lead, arsenic, chromium, mercury, cadmium, and zinc. Chlorinated solvents like trichloroethene and tetrachloroethene, polychlorinated biphenyls (PCBs), pesticides including DDT and chlordane, polycyclic aromatic hydrocarbons (PAHs), benzene, toluene, naphthalene, and RDX have also been detected. The Navy is separately investigating per- and polyfluoroalkyl substances (PFAS), specifically PFOA and PFOS, linked to firefighting foam used at the facility. EPA identified over 150 chemical substances as contaminants of concern across areas such as chemical burn pits, landfills, disposal burn areas, and a pesticide rinse area.
The Navy leads cleanup under a 1994 Federal Facilities Agreement with EPA and the Virginia Department of Environmental Quality (DEQ). Records of Decision (RODs) documenting selected cleanup methods have been issued for 19 of 22 operable units. Of the 76 sites, 55 have been cleaned up and closed. The remaining 21 include 10 in long-term monitoring, 5 undergoing remedial investigation or remedy selection, 3 new PFAS sites, and 3 deferred sites on active munitions ranges. Cleanup methods at various sites include excavation, offsite disposal, capping, and monitoring. Some sites require no further action. The most recent five-year review, completed in December 2023, found that response actions are protective of public health and the environment. Active investigations continue at sites like the Gambo Creek Ash Dump and Chemical Waste Pond, with key study deadlines running into 2027 and 2028.
Human exposure is currently under control, meaning assessments show no unacceptable pathways for people to contact contaminants. However, groundwater migration has not fully stabilized due to insufficient data. Institutional controls are in place, including groundwater use restrictions that prohibit drinking water use from the site and zoning restrictions that prevent residential development.
Community members can engage through the Restoration Advisory Board (RAB), which holds public meetings on an as-needed basis. The Naval Support Facility Dahlgren website provides ongoing updates on cleanup status. People can also participate through EPA's Community Involvement Program. Questions can be directed to EPA Remedial Project Manager Brian Poe, Navy Remedial Project Manager Josh Coe, or Virginia DEQ Remedial Project Manager Eric Salopek.
