The Bally Ground Water Contamination site covers 20 acres in Bally Borough, Pennsylvania. A former industrial facility disposed of solvent waste in on-site impoundments from roughly 1955 to 1965, contaminating the aquifer that supplies drinking water to Bally Borough and Washington Township. EPA placed the site on the National Priorities List (NPL) in 1987 after contaminated wells were discovered in 1982.
Nine contaminants of concern have been identified in the groundwater, all volatile organic compounds (VOCs) or related chemicals. They include trichloroethene, tetrachloroethene, 1,4-dioxane, 1,1,1-trichloroethane, 1,1-dichloroethane, 1,1-dichloroethene, 1,2-dichloroethane, and dichloromethane (also called methylene chloride). The 1,4-dioxane is a probable carcinogen and was found in the municipal water supply in 2003. Drinking contaminated groundwater or direct contact with it presents potential health risks from these compounds.
Cleanup has addressed the groundwater plume, the public water system, and vapor intrusion at the former plant building. An air-stripper system installed in 1989 treats contaminated groundwater before it reaches the municipal supply. When 1,4-dioxane was discovered and could not be removed by the existing air-stripper, EPA decided in 2007 to install a new municipal supply well, which was completed in August 2010. Sampling confirmed that 1,4-dioxane was no longer a concern and that water met Safe Drinking Water Act standards. A pipeline to discharge the originally contaminated well to West Branch Perkiomen Creek was completed in 2012. A vapor intrusion mitigation system was installed at the former plant in 2009, with ongoing indoor air monitoring. The potentially responsible party is now evaluating ways to optimize the treatment and monitoring systems.
The site achieved sitewide ready for anticipated reuse status in January 2013. As of December 2024, nine businesses on the property employ 21 people in light manufacturing, storage, and office work. Human exposure is under control with no unacceptable exposure pathways currently present. Institutional controls prevent private wells from tapping into the contamination plume and restrict uses such as residential development. EPA's most recent five-year review, completed in May 2025, concluded that the remedy is protective of human health and the environment. The site has not yet been deleted from the NPL.
Community members can get involved through EPA's Community Involvement Program. Key documents available for public review include the Community Relations Plan, Record of Decision amendments, vapor intrusion mitigation reports, and fact sheets on soil vapor sampling. Records can be viewed at the Boyertown Community Library at 24 N Reading Avenue in Boyertown, Pennsylvania, or at the EPA Region III office in Philadelphia by appointment.
