Kearsarge Metallurgical Corporation ran a precision stainless steel casting operation in Conway, New Hampshire from 1964 to 1982. The company dumped waste casting sands, wax, and solvents into a wooded wetland east of the facility. That waste contaminated groundwater with volatile organic compounds, mainly 1,1,1-trichloroethane and its breakdown products. EPA placed the site on the National Priorities List in September 1984.
The site contains 26 contaminants of concern. Volatile organic compounds found in groundwater include 1,1,1-trichloroethane, 1,1-dichloroethane, 1,1-dichloroethene, 1,2-dichloroethane, 1,2-dichloroethene, acetone, chloroform, trichloroethene, and 1,4-dioxane. Metal contaminants include chromium, copper, mercury, and nickel, found across soil, groundwater, surface water, sediment, and solid waste.
Cleanup began in earnest in 1990. Workers removed 13,620 tons of waste pile material between 1992 and 1993. A groundwater pump-and-treat plant operated from 1993 to 2005 and cleared up contamination west of Hobbs Street by 2003. On the east side, 5,670 tons of contaminated soil were excavated in 2003. After pumping stopped, contaminant levels failed to improve, so in fall 2015 contractors applied a soil mixing and soil treatment remedy. The New Hampshire Department of Environmental Services is monitoring groundwater to check how well that 2015 treatment is working.
EPA's most recent five-year review, completed in August 2023, found that response actions are protective of human health and the environment in the short term. Continued long-term protectiveness requires ongoing monitoring of institutional controls and groundwater. Human exposure and groundwater migration are both considered under control. Physical construction is complete across the entire site, and all cleanup goals for current and anticipated future land uses have been met. The Town of Conway owns the property. Institutional controls restrict land use, including residential development, and will stay in place as long as contamination or cleanup components remain on site. Three businesses now operate there, employing six people and generating about $755,630 in annual sales. The next five-year review is estimated for August through October 2028.
Community members with questions can contact EPA Community Involvement Coordinator Liz McCarthy by email or phone. The EPA Remedial Project Manager is Gerardo Milan-Ramos. State inquiries can go to Brian Thornton at the New Hampshire Department of Environmental Services. Site documents are available at the Conway Public Library and at EPA Region 1 in Boston.
