Naval Air Station Joint Reserve Base Willow Grove

Naval Air Station Joint Reserve Base Willow Grove is a former Navy installation in Horsham Township, Montgomery County, Pennsylvania. The airfield dates to 1926, when aviation pioneer Harold Pitcairn built a hangar and grass airstrip there; the Navy purchased the property in 1942 and commissioned it as Naval Air Station Willow Grove in January 1943. After World War II the station served primarily as a Naval Air Reserve training facility, and in 1994 it was redesignated a Joint Reserve Base to reflect combined operations by Navy, Marine Corps, Air Force, and Army reserve units alongside the Pennsylvania Air National Guard. Selected for closure in the 2005 Base Realignment and Closure round, the roughly 900 acre installation ceased operations in 2011, although the adjacent Horsham Air Guard Station remains active.

There are concerns about potential carcinogenic health hazards at NAS JRB Willow Grove, due to documented exposure to a number of environmental contaminants:

1. PFAS: Per- and polyfluoroalkyl substances, often called forever chemicals because they resist breaking down in the environment, have been identified at Willow Grove in soil, groundwater, surface water, and sediment. Groundwater near the base has tested at 329,500 parts per trillion of combined PFOS and PFOA, and contamination migrated into drinking water supplies serving Horsham Township and nearby Montgomery and Bucks County communities, including private wells in Horsham, Warminster, and Warrington. PFAS exposure has been associated in some studies with kidney and testicular cancers, thyroid disease, and immune system effects.
2. PFOS: Perfluorooctane sulfonate, one of the most studied PFAS compounds, was among the chemicals ATSDR evaluated in exposure dose calculations for Horsham public water. PFOS persists in the body for years and has been associated with potential adverse health outcomes, including possible links to certain cancers.
3. PFOA: Perfluorooctanoic acid was also detected in water supplies affected by the base. PFOA has been classified as carcinogenic to humans by the International Agency for Research on Cancer, and exposure may potentially be linked to kidney cancer and other conditions.
4. AFFF: Aqueous film forming foam, a PFAS-containing fire suppressant, was used routinely at Willow Grove in firefighting and fire training activities beginning in the 1970s. This foam is considered the likely source of the PFAS contamination found in area groundwater and drinking water.
5. Solvents: Volatile organic compounds, including industrial solvents associated with aircraft operations and maintenance, have been detected in groundwater at the site. Long term exposure to certain solvents has been associated with elevated cancer risks.
6. Heavy metals: Metals have been found in soil at the installation. Depending on the metal and the level of exposure, some heavy metals are recognized or suspected human carcinogens.

The Willow Grove site was added to the EPA's National Priorities List of Superfund sites in 1995. Cleanup is organized into thirteen operable units across the Navy and Air National Guard portions of the property, including dedicated units established specifically to address PFAS. The EPA has issued cleanup decisions for several units, others remain under investigation, and five year reviews were completed in 2023. ATSDR has published a public health assessment documenting exposure pathways and supported biomonitoring studies in nearby communities.

It is important to note that while there are documented concerns about potential exposure to these contaminants at NAS JRB Willow Grove, establishing definitive links between service at the base and any individual diagnosis can be complex, and research into PFAS and the other substances found here is ongoing. Veterans and family members who lived or worked at Willow Grove may wish to stay informed about new findings and consult the Department of Veterans Affairs about health evaluations and potential benefits.