EPA Selects Remedy for North Penn Site

July 8, 2004

The U.S. Environmental Protection Agency has selected a remedy for contaminated soil and groundwater at the North Penn Area 5 Superfund site in Montgomery and Hatfield Townships in Montgomery County, Pennsylvania. The remedy requires reducing the contamination at its source through in-situ chemical oxidation. In addition, the remedy calls for the design and construction of a system to pump and treat contaminated groundwater.

The remedies were selected because they will provide the most overall protection and meet all state and federal regulations. They will restore groundwater quality by aggressively treating and eliminating areas which are the sources of contamination. This restoration will allow for unlimited use of, and unrestricted access to the groundwater in the future.

The North Penn 5 site encompasses about five square miles and is one of six sites, within the North Penn Water Authority (NPWA) service area that were added to the Superfund National Priorities List in March 1989. The site came to the attention of state and federal authorities when volatile organic compounds including tricloroethylene (TCE), a probable human carcinogen were discovered in a NPWA supply well in 1979.

The remedy announced today requires source reduction using in-situ chemical oxidation for groundwater that is contaminated with TCE. In-situ chemical oxidation is a process that involves adding non-hazardous chemicals such as potassium permanganate to the source areas to create a reaction which transforms toxins in the soil and groundwater to harmless byproducts.

A pump and treat system will be built to prevent off-site migration of contaminated groundwater. The remedy also calls for a hydrogeologic study to determine the most effective design and monitoring system for the groundwater.

Source: U.S. Environmental Protection Agency