Old Wilmington Road Ground Water Contamination

Overview

The Old Wilmington Road Ground Water Contamination site sits in West Caln Township, Chester County, Pennsylvania. The Pennsylvania Department of Environmental Protection found groundwater contamination during an inspection of the nearby Perry Phillips Landfill. EPA added the site to the Superfund National Priorities List in February 2000. The site is divided into two operable units. Operable Unit 01 covers sitewide vapor intrusion and groundwater contamination. Operable Unit 02 does not yet have a decision document, and a combined remedial investigation and feasibility study for it is estimated to begin between June and August 2027.

Contaminants found at the site include 1,4-dioxane, vinyl chloride, chloroform, perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), tetrachloroethene, and trichloroethene. These chemicals appear in groundwater, soil gas, and indoor air. In 2021, PFAS were discovered in a well serving an adjacent mobile home park and in some residential wells. EPA is providing bottled water to certain nearby residents because of new federal drinking water standards for PFAS. Current data is insufficient to determine whether human exposure is under control or whether the groundwater plume has stabilized.

EPA has been taking action at this site for years. The agency ran removal actions in three phases: December 1993 through June 2000, April 2018 through July 2019, and December 2022 through January 2024. Carbon-filtration systems were installed at affected homes to remove VOCs and metals from drinking water. A Record of Decision issued April 14, 2023 selected the cleanup approach for Operable Unit 01, which includes connecting homes to a municipal water supply, sub-slab depressurization, vapor intrusion mitigation systems, indoor air monitoring, and institutional controls. An Explanation of Significant Differences issued February 21, 2024 documented modifications to that remedy. Remedial action started in September 2025. Construction of a new public waterline began March 2, 2026, and is progressing from Ash Road toward Old Mill Road. About 90 properties were offered connections, and roughly 50 opted in. Remedial action for Operable Unit 01 is estimated to finish between June and August 2028.

Community members can get involved through EPA's Community Involvement Program. A public meeting was held January 22, 2026 at the Wagontown Fire Company to discuss cleanup and construction impacts. The Administrative Record for the site is available online or in person at the Coatesville Area Public Library at 501 East Lincoln Highway in Coatesville, Pennsylvania, and at the U.S. EPA Region 3 office at 1600 John F. Kennedy Boulevard in Philadelphia, Pennsylvania. The Pennsylvania Department of Environmental Protection continues to monitor the mobile home park's drinking water well. Questions can be directed to EPA staff assigned to the site.