North Penn - Area 5

Overview

North Penn - Area 5 is a Superfund site in the Colmar and Hatfield Township area of Montgomery County, Pennsylvania. It was added to the National Priorities List in March 1989 after chlorinated solvent contamination was found in a North Penn Water Authority drinking water well in 1979. The site is organized into three operable units, each covering a different groundwater plume. Most homes near the site use municipal drinking water and are not at risk from the contaminated groundwater.

The contaminants are chlorinated solvents found in three separate groundwater plumes. They include trichloroethene, tetrachloroethene, vinyl chloride, 1,1,1-trichloroethane, 1,1-dichloroethene, cis-1,2-dichloroethene, trans-1,2-dichloroethene, 1,2-dichloroethane, and 1,1,2,2-tetrachloroethane. All contamination is in groundwater. Contaminated groundwater is still moving and has not yet stabilized.

Cleanup approaches differ by operable unit. Operable Unit 1 (OU1), near a facility owned by Cobham Advanced Electronic Solutions, Inc., is undergoing an optimized pump and treat system. EPA approved the design in May 2025, and construction is expected to finish by mid-2026. Operable Unit 2 (OU2), near a vacant former manufacturing facility, requires more study of deep groundwater. EPA is negotiating with responsible parties to conduct a Focused Feasibility Study, and vapor intrusion monitoring is ongoing at the facility above the contamination. A 2025 administrative order initiated that focused feasibility study. Operable Unit 3 (OU3), near commercial facilities on Advance and Enterprise Lane, has low but above-cleanup-level contamination. EPA is conducting semi-annual groundwater sampling to evaluate new cleanup alternatives. The Stabilus plume remedial action was completed in October 2021.

Two sources describe the cleanup status differently. One source states that human exposure cannot yet be determined due to insufficient data. The same source confirms that groundwater migration is not currently under control and that physical construction remains incomplete. The site has not been deleted from the National Priorities List and is not yet ready for anticipated reuse. At the same time, as of December 2024, the site hosted 10 businesses employing 816 people and generating roughly $379.6 million in annual sales revenue, reflecting ongoing economic activity at the location.

Community members can get involved through EPA's Community Involvement Program, which supports early and meaningful participation in cleanup decisions. Key cleanup decisions are documented in Records of Decision for OU1 and OU3 from 2004, an Interim Action for OU2 from 2011, and an OU1 amendment from 2016. Public records can be reviewed at the Lansdale Public Library, the Montgomery Township Municipal Building in Montgomeryville, or the EPA Region 3 office in Philadelphia. Appointments should be scheduled in advance. Community members with questions can contact the EPA staff assigned to the site.