The Nuclear Metals, Inc. site is a 46-acre former manufacturing facility in Concord, Massachusetts. It operated from 1958 to 1985, producing depleted uranium products, metal powders, and specialty metals like beryllium tubing. Waste discharged into an unlined holding basin contaminated soil, sediment, and groundwater with hazardous chemicals. The site was added to the National Priorities List in June 2001 and is currently in the Remedial Design and Remedial Action stage of cleanup.
EPA has identified 37 contaminants of concern across the site. Groundwater contains trichloroethene, vinyl chloride, 1,1,2,2-tetrachloroethane, 1,4-dioxane, arsenic, chromium, lead, uranium, and thorium-232. Soil holds arsenic, polychlorinated biphenyls (PCBs), uranium isotopes, thorium-232, and polycyclic aromatic hydrocarbons. Sediment contains copper, lead, mercury, and PCBs. The Assabet River runs along part of the northern boundary of the property. The groundwater is not used as a public drinking water source, and the site is fenced to prevent public contact with contaminated areas. EPA has determined that human exposure and groundwater migration are currently under control.
Cleanup actions began in 2002 with soil removal from the holding basin and removal of over 3,800 drums of depleted uranium and other materials. EPA issued its final cleanup decision in September 2015, selecting a roughly $125 million remedy that includes excavating about 82,500 cubic yards of contaminated material, treating groundwater, and capping the holding basin area. A groundwater extraction and treatment system became operational in June 2019 to protect the Town of Acton's water supply wells from 1,4-dioxane. Remedial action started in September 2022 and includes iron injections to address depleted uranium in groundwater and multi-phase soil and sediment excavations. Phase 1 excavations were completed in November 2024. In March 2025, EPA added requirements to address asbestos transite piping discovered during excavation, a change that does not fundamentally alter the 2015 cleanup plan. Construction is estimated to wrap up between September and November 2028, with additional work at the landfill and cooling pond planned through 2029.
Community members can follow progress through monthly fact sheets, with the most recent issued in May 2025. EPA held a public meeting in April 2025 to discuss the site's history and current activities. Documents are available online at www.epa.gov/superfund/nmi, at the Concord Public Library at 129 Main Street, or at the EPA Region 1 office in Boston. Redevelopment planning is ongoing between EPA and the Town of Concord.
