The Fort Devens-Sudbury Training Annex is a former U.S. Army facility that once covered about 2,750 acres across Sudbury, Hudson, Stow, and Maynard, Massachusetts. It operated as an ammunition depot, ordnance test station, troop training area, and laboratory disposal facility from 1942 until it closed in 1995. EPA added it to the National Priorities List in 1990 after finding contamination from pesticides and other chemicals. The site was deleted from that list in 2002 after cleanup goals were met.
Cleanup addressed contaminated soil and groundwater across five operable units, or distinct problem areas. Arsenic and thallium were found in soil in Area A9. Remedies included soil excavation, an engineered cap on the Old Gravel Landfill, removal of underground storage tanks, and groundwater monitoring. Most areas received a "no action" decision after further review showed risks were within acceptable limits. The Army still monitors and maintains the capped landfill every year.
A newer concern has emerged since the original cleanup. PFAS, a group of manufactured chemicals, was found in a drinking water well near the north gate at levels above Massachusetts drinking water standards, making that well unsafe to use. The Army investigated PFAS at two former contaminated areas between 2017 and 2021. As of March 2025, the Army is conducting a full remedial investigation to measure PFAS in soil, groundwater, surface water, and sediment. A second remedial investigation for Area A9 began in January 2024, with a record of decision amendment estimated for 2028.
EPA has determined that human exposure to contamination is currently under control across the entire site, and contaminated groundwater migration is stabilized with no unacceptable discharge to surface water. Institutional controls, including zoning restrictions, remain in place to prevent residential development and other incompatible land uses. Much of the land has been transferred to the U.S. Fish and Wildlife Service, which runs the Assabet River National Wildlife Refuge there, offering hiking, fishing, canoeing, and guided tours. The Army's fifth Five-Year Review was completed in September 2021, and the next review is scheduled for completion by September 2026.
Community members with questions about the site can contact EPA's Community Involvement Coordinator, Zanetta Purnell, by phone or email. The Army's point of contact is Thomas Lineer. Public records are available online through the EPA Superfund website and at two physical locations: the Devens Regional Facility Training Area office in Devens, Massachusetts, and the EPA Region 1 records center in Boston.
