The Kimberton site covers 45 acres in East Pikeland Township, Chester County, Pennsylvania. The Henry Company has manufactured asphalt products there since 1969. Contaminated groundwater flows north-northeast toward the Village of Kimberton and drains into streams that reach the Schuylkill River. The site was added to the National Priorities List, a federal register of the most serious hazardous waste sites, in September 1983.
EPA identified ten contaminants of concern, all found in groundwater and some also in surface water. These include trichloroethene, vinyl chloride, 1,1-dichloroethene, 1,2-dichloroethene, and cis-1,2-dichloroethene. All are chlorinated volatile organic compounds commonly linked to industrial contamination.
Cleanup addressed two main problems. For drinking water, a 1986 Consent Order required granular activated carbon filters on 23 residential wells and potable water tanks for two commercial locations. A public water supply line completed in 1991 and 1992 replaced those temporary measures. For groundwater, a pump-and-treat system has operated since December 1993. Ten extraction wells pull contaminated groundwater into a treatment building where an air stripper removes volatile organic compounds. The system treats up to 250 gallons per minute and discharges about 85 million gallons of treated water per year to a local stream. Vapor intrusion was identified as a concern in 2009. Mitigation systems were installed at an on-site warehouse and an off-site residence, and sampling in 2013 and 2014 confirmed they were working properly. Institutional controls restrict land use, protect capped areas, and guard against vapor intrusion risks.
Physical construction across the entire site is complete. Human exposure is under control, and contaminated groundwater migration is stabilized with no unacceptable discharge to surface water. The site was designated Sitewide Ready for Anticipated Use in 2018. One on-site business currently operates, employing 300 people. A long-term response action for the second operable unit remains ongoing, and the site has not been deleted from the NPL. EPA completed its seventh five-year review in April 2024, confirming the remedy remains protective of human health and the environment. The next five-year review is scheduled for 2029.
Community members can get involved through EPA's Community Involvement Program. Site records are available online and at the East Pikeland Township Building in Phoenixville, the Phoenixville Public Library, and the EPA Region 3 office in Philadelphia. Appointments are required to review materials at physical locations.
