The Cheshire Ground Water Contamination site covers 15 acres in Cheshire, Connecticut. Companies conducted plastic molding and electronic device manufacturing there from 1966 to 1980, releasing chemicals and solvents into the soil and groundwater beneath the property. The EPA (Environmental Protection Agency) added the site to its National Priorities List, or NPL, in August 1990. The NPL is the federal list of the most contaminated sites in the country.
EPA identified 43 contaminants of concern across the site. Groundwater contains chlorinated solvents including 1,1,1-trichloroethane, 1,1-dichloroethane, and 1,1-dichloroethene, along with metals such as arsenic, chromium, lead, nickel, and manganese. Soil contamination includes pesticides like DDT, dieldrin, and alpha-chlordane, polycyclic aromatic hydrocarbons such as benzo[a]pyrene, and metals including arsenic, cadmium, chromium, beryllium, and mercury. The primary risks come from people ingesting or touching contaminants in soil or groundwater.
Cleanup work began in October 1983 when past landowners removed 20 cubic yards of contaminated soil. Municipal water was extended to residents whose drinking water wells were affected. EPA completed a remedial investigation and feasibility study between September 1994 and December 1996, then issued a Record of Decision selecting "No Action" as the final remedy. That decision reflected a 1996 EPA finding that remaining contamination levels did not pose an unacceptable threat to public health or the environment. The site was deleted from the NPL in July 1997.
Human exposure is currently under control, and groundwater migration is also under control, with contaminated groundwater stabilized and no unacceptable discharge to surface water expected. No institutional controls are required, meaning no restrictions on land use are needed because no contamination remains at levels that could cause unacceptable exposure. The site achieved sitewide ready for anticipated reuse status in April 2008. Today, one business operates on the property, employing 19 people and generating an estimated $6,880,000 in annual sales revenue.
Community members who want more information can contact EPA staff directly. Site records are also available at the Cheshire Public Library in Cheshire or at the EPA Region 1 Records and Information Center in Boston.
