Contaminant concerns prompt EPA to expand public water connections in New Hampshire

The U.S. Environmental Protection Agency (EPA) has finalized an Interim Record of Decision (IROD) for the Tinkham Garage Superfund Site in Londonderry, New Hampshire, selecting a plan to extend municipal water service to neighborhoods where groundwater contamination has affected or could affect drinking water wells.

The finalized plan calls for expanding the existing municipal water line to connect homes impacted by site-related contaminants, including 1,4-dioxane and per- and polyfluoroalkyl substances (PFAS). These substances were first detected in 2018 at concentrations posing “an unacceptable current and future risk to human health and the environment,” according to EPA.

Since the discovery, EPA and responsible parties have provided bottled water to households with detections above federal or state standards as a temporary mitigation measure. The agency’s decision to pursue a new remedy marks a fundamental change from earlier cleanup plans and follows a public comment period.

The 375-acre Tinkham Garage site includes residential and commercial properties and conservation land in Londonderry. The IROD and related documents are available on EPA’s website or at the Leach Library in Londonderry.