PFAS Data

The Department of War (DoW) continues to prioritize actions to address cleanup at locations that pose the greatest risk to human health and will continue to accelerate cleanup efforts nationwide in accordance with the federal cleanup law, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), and in partnership with regulatory agencies and affected communities.

The Department fully investigates a potential release and determines the appropriate cleanup actions based on risk. Through September 30, 2025, DoW has determined that 723 active military installations, Base Realignment and Closure (BRAC) locations, National Guard facilities, and Formerly Used Defense Sites (FUDS) properties require an assessment of per- and polyfluoroalkyl substances (PFAS) use or potential release. DoW performed Preliminary Assessments/Site Inspections (PA/SIs) at these installations, which is the first phase of the cleanup process and may take two to three years to complete. As of September 30, 2025, DoW has completed the PA/SI phase at 704 installations. The Department has determined that no further action is required at 116 of these installations, while 588 are proceeding to the next step in the CERCLA process (i.e., Remedial Investigation (RI)). DoW will prioritize sites as they move into the RI-phase based on relative risk and through the RI-phase will determine appropriate cleanup actions based on the extent of the release, the impacted media and identified risk.

The Department’s timeline for cleanup response actions is dictated by CERCLA, and its regulations, and reflects an evolving understanding of PFAS releases on its military installations. While DoW strives to maintain original schedules, shifts may occur due to unique factors encountered at some sites. At some installations, there may be multiple reasons for a shift. If a schedule is modified, the reasons are provided in the status chart for the 723 installations where the Department is investigating PFAS releases.

DoW can also take interim actions at any phase during the CERCLA process. Interim cleanup actions can include removal of soil “hot spots” and installation of groundwater extraction systems. Locations of interim actions currently in progress are illustrated on this map or can be viewed on this list.

As DoW moves through the CERCLA process, the Department works in collaboration with regulatory agencies, communities, and facilities to ensure open and transparent information sharing.

PFAS in Groundwater

DoW addresses PFOS and PFOA in groundwater that is not consumed as drinking water under CERCLA (click here for an overview of the CERCLA process). Groundwater is underground water that resides within the cracks, crevices and spaces in soil, sand, and rock. Cleaning up groundwater is often technically complex and takes many years to complete. DoW tailors the actual sequence, timing, and scope of cleanup actions to site-specific conditions. Additionally, the Department prioritizes resources and addresses sites where risk to human health is the highest using the Relative Risk Site Evaluation (RRSE) framework. If at any time during the CERCLA process, DoW identifies a location where there is an imminent risk to human health, DoW performs an interim removal action. This removal action mitigates the risk to human health while still allowing the site to continue through each phase of the CERCLA process and identify any additional actions that may be needed to fully cleanup the site.

DoW Cleanup Actions to Address Off-Base Drinking Water

DoW conducts sampling of drinking water off-base to ensure it identifies potential impacts of PFAS resulting from previous DoW activities. PFOS and PFOA were found above 70 parts per trillion (ppt) in drinking water resulting from DoW activities at 55 installations and the Department took immediate action to address the drinking water exposure.

Moving forward, the DoW Components will initiate interim actions to address private drinking water wells impacted by PFAS from DoW activities where concentrations are known to be at or above three times the Maximum Contaminant Levels (MCL) values (i.e., PFOA = 12 ppt; PFOS = 12 ppt; PFHxS = 30 ppt; GenX = 30 ppt; PFNA = 30 ppt; HI = 3). The Department is prioritizing action where PFAS levels from DoW releases are the highest, rather than delay action at these locations while ongoing remedial investigations continue.

View final testing results for PFAS in off-base drinking water in areas in the United States located adjacent to and down gradient from a DoW military installation, FUDS, or National Guard facility.