LONDONDERRY – The U.S. Environmental Protection Agency recently released a proposal for an interim remedy to address drinking water contamination at the 375-acre Tinkham Garage Superfund Site on Rt. 102.

The next public hearing will be held on July 29 at 6 p.m. at the Moose Hill Council Chambers, 268 Mammoth Rd., Unit B, in Londonderry.

The EPA is accepting public comments on the proposed plan until Aug. 12.

The EPA considered several options which would provide alternative water to mitigate risk for residents who rely on groundwater as their drinking water source within target neighborhoods. The EPA is seeking public comment on the preferred interim remedy and will offer public meetings to receive input. After the public has had an opportunity to review and provide comments, the EPA expects to finalize the decision in September.

The EPA’s preferred alternative for the interim remedy in the proposed plan has been designed to prevent current and future human health exposure to, and risk from, ingestion of contaminated groundwater used as drinking water. This interim action will be a part of a final remedy at the site which will be selected at the completion of on-going remedial investigations. The proposed plan includes:

-Extension of the existing municipal water line into target neighborhoods where groundwater is used as a drinking water source, and the connection of homes impacted or potentially impacted by site-related contaminants of concern that were not previously connected to the existing water line.

-Disconnection of private water supply wells from the contaminated groundwater. Continued long-term monitoring of groundwater and periodic reviews, at a minimum of every five years, to assess the effectiveness and protectiveness of the remedy.

-The estimated total value of this proposed cleanup approach, including design and construction of the waterline is approximately $6.8 million.

The site is comprised of residential, commercial and undeveloped conservation land. In addition to the 13-unit Woodland Village Condominium complex, 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.

The presence of volatile organic compounds (including 1,4-dioxane) and per- and polyfluoroalkyl substances have been 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 Agencies as a temporary mitigation measure.

Copies of the detailed proposed plan, as well as historical information about the EPA’s efforts at the Tinkham Garage Superfund Site may be viewed on the EPA’s website at: www.epa.gov/superfund/tinkham or at the site’s information repository at Leach Library, 276 Mammoth Rd.