EPA Superfund site
LETTERKENNY ARMY DEPOT (SE AREA)
Human exposure is NOT currently under control
Data limitations: Proximity to a Superfund site boundary does not mean your property is contaminated. EPA site boundaries show the area designated for cleanup, not the full extent of contamination. Groundwater plumes can extend beyond site boundaries. This tool shows publicly available EPA federal data. It is not affiliated with or endorsed by EPA, and is not a substitute for a professional environmental assessment.
About this site's exposure pathways
As of April 2026, the Letterkenny SE Superfund site is considered ‘Current Human Exposure Not Under Control’ (HENC); this is a change from the previous designation of “Insufficient Data to make a Human Exposure evaluation” (HEID). Newly identified contaminants, per- and polyfluoroalkyl substances (PFAS), were detected in private drinking water off-base during sampling efforts conducted in 2022 and 2024. Some residential drinking water wells have been identified with perfluorooctanoic acid (PFOA), PFHxS and perfluorooctanesulfonic acid (PFOS) values that exceed the Pennsylvania Maximum Contaminant Levels (MCLs) and EPA MCLs for PFOA and PFOS that have not been addressed. A Remedial Investigation is ongoing to determine the nature and extent of the PFAS contamination both on and off-site at the Base. Currently, the planned activities by the Army to address this pathway are expanded residential sampling and performing an Engineering Evaluation/Cost Analysis process to provide alternative drinking water. EPA currently anticipates that human exposure will be under control by April 2027 because alternative drinking water will be provided to eliminate this exposure pathway. For more information on ways you may be able to reduce your exposure to PFAS, please visit the following page: https://www.epa.gov/pfas/meaningful-and-achievable-steps-you-can-take-reduce-your-risk