EPA Announces Plan to Address Drinking Water Contamination at New Hampshire Superfund Site

EPA Announces Plan to Address Drinking Water Contamination at New Hampshire Superfund Site

October 22, 2025

BOSTON (October 22, 2025) - U.S. Environmental Protection Agency (EPA) has finalized the Interim Record of Decision (IROD) for the Tinkham Garage Superfund Site in Londonderry, New Hampshire. The IROD finalizes EPA's preferred alternative to extend the existing municipal water line into certain target neighborhoods where groundwater is used as a drinking water source. This plan also covers connections of homes affected or potentially affected by the site-related contaminants of concern that were not previously connected to the existing water line.

In 2018, the presence of 1,4-dioxane and per- and polyfluoroalkyl substances (PFAS) were identified in groundwater at the site and in groundwater and water supply wells downgradient from the site at levels that present an unacceptable current and future risk to human health and the environment. Groundwater is used as drinking water downgradient of the site and monitoring has continued since 2018. Households with detections above federal and/or state standards have been offered bottled water by the Responsible Parties or by the EPA as a temporary mitigation measure.

The selection of a different, documented remedial alternative represents a fundamental change to the selected remedy, as specified in the IROD. A final decision was made after consideration of public comments.

Copies of the IROD and Administrative Record can be found at https://www.epa.gov/superfund/tinkham. If you do not have internet access to view these documents, you can view this information at the Leach Library, located at 276 Mammoth Road, Londonderry, NH 03053.

Background
Located in Londonderry, New Hampshire, the roughly 375-acre Tinkham Garage Superfund Site is comprised of residential, commercial, and undeveloped conservation land. In addition to the 13-unit Woodland Village Condominium complex (formerly the Londonderry Green Apartments), there are single family homes along Mercury and McAllister Drives to the north, along Gilcreast Road and the Boston/Charleston/Albany neighborhood to the northeast, and the Ross/Tokanel neighborhood to the east and southeast.