Superfund Site Profile

  • The EPA is sampling private drinking water wells in the area of Willow Grove Naval Air station Joint Reserve Base in Horsham, PA for perfluorinated chemicals (PFCs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).
  • As of January 9, 2015, of the 333 wells identified to be sampled, 206 have been sampled and 182 wells have validated results. There are 37 wells which exceed provisional health advisory levels of 0.2 micrograms per liter of water for PFOS and 0.4 micrograms per liter of water for PFOS. There are 51 properties receiving bottled water.

October 2015 Drinking Water Fact Sheet 


This 1,200 acre site is comprised of the Naval Air Station Joint Reserve Base Willow Grove (NASJRB/WG) and the Willow Grove Air Reserve Station (WGARS), which are operating U.S. Navy and U.S. Air Force installations, respectively, located in Montgomery County, Pennsylvania. The installations are co-located within one perimeter and are located approximately 25 miles north of Philadelphia. Aircraft operations at the site began during the 1920s when the facility was named Pitcairn Airfield. The U.S. Navy acquired the airfield in 1942 and began jet training there in 1949. Currently, NASJRB/WG and WGARS provide materials, facilities, services, and training in direct support of all units assigned to the stations. The site was listed on the EPA's National Priorities List on September 29, 1995.

Activities that generate, store, or dispose of hazardous waste at the facilities fall into four general categories: (1) aircraft maintenance; (2) base civil engineering; (3) fuel operation and (4) personnel training. Sources of potential contamination on Navy property include, but are not necessarily limited to, the Privet Road Compound, Antenna Field Landfill, Ninth Street Landfill, the former Fire Training Area and a fuel farm.

On the Air Force property, a washrack area, a stormwater retention basin, a fuel farm, and a number of hazardous waste storage areas have been identified as potential sources of contamination.

Analysis of groundwater samples collected from wells located near the Privet Road Compound area, which is near the border of the Navy and Air Force properties revealed contamination from various chemicals. Samples from two Navy drinking water supply wells showed levels of tetrachlorethene (PCE) above EPA-established health-based levels. Water form the Navy potable water production wells receives preliminary treatment (air stripping) to remove volatile organic compounds (such as PCE) before entering a storage tank. Treated water in the storage tank is monitored to ensure no levels of potentially harmful contaminants are reached. Water from the storage tank is further treated for bacterial disinfection and testing prior to distribution throughout the base for drinking and other uses.

Over 800 employees at the two facilities may consume or come into contact with treated water from the Navy supply wells. The source(s) of contamination found in groundwater is under investigation by EPA Site Assessment Branch.