EPA v. WILLOW GROVE NAVAL AIR & AIR RESERVE STATION

Case summary

Naval Air Station Joint Reserve Base, Willow Grove, Horsham, PA - On December 15, 2025, EPA concurred on the final Action Memorandum for a large-scale groundwater pump and treat system for PFAS sources areas on the Navy side of Willow Grove. The Navy had previously conducted two successful pilot studies in these areas. The PFAS treatment system will consist of treatment with GAC and single-use ion exchange resin with final discharge to Park Creek. The public is generally in support of this action, but there were concerns about flooding at Park Creek and potential drawdown of nearby potable groundwater, both of which have been addressed by the Navy. The Navy also built in additional capacity of the system in anticipation of possibly expanding extraction as part of the long-term remedy and/or treating groundwater from the adjacent Biddle Site. We expect an Air National Guard Action Memorandum to pump and treat groundwater on the Biddle side sometime in 2026. On June 27, 2005, Region III signed a Federal Facility Agreement for Naval Air Station Joint Reserve Base (NAS JRB) Willow Grove, in Horsham, PA. The Federal Facility Agreement was entered into and signed by EPA, the Department of the Navy, and the Pennsylvania Department. The Federal Facility Agreement is entered into pursuant to the Comprehensive Environmental Response, Compensation and Liability Act ( CERCLA ), 42 U.S.C. 9620. OU-2 THE SUSPECTED SOURCE OF CONTAMINATION AT OU-2 IS A SPILLAGE OF WASTE VOCs TEMPORARILY STAGED ALONG THE ACCESS ROAD BEFORE BEING TRANSFERRED TO THE FORMER BURN RING AND MINOR AMOUNT OF PAHs IN WASTE LIQUIDS THAT WERE SPILLED IN THE IMMEDIATE VICINITY OF THE BURN RING DURING BURNIING. The 09/2015 Action Memorandum documents the decision by the Department of the Navy to conduct a time-critical removal action (TCRA) to mitigate potential public exposure to perfluorinated compounds (PFCs) in drinking water (including providing bottled water to residents). Discharges of Aqueous Film Forming Foam (AFFF) may have occurred during firefighter training activities and spills of AFFF during airfield operations. Perfluorooctanoic Acid (PFOA) and /or Perfluorooctane Sulfonate (PFOS) may be components of some AFFF solutions. In 2011, PFOA and PFOS were detected in groundwater at Installation Restoration Program (IRP) Site 5 ? Former Fire Fighting Training Area, OU-2. Removal (6/19/18) for OU-12: TCRA for removal of highest concentrations of PFOS in soil. Removal (11/30/17) for OU-12: TCRA added carbon treatment to municipal wells above lifetime health advisory for PFAS. Removal (11/30/17) for OU-12 TCRA to connect residences to municipal wells because their private wells had PFOS above health advisory. On October 21st, EPA signed the ROD for the Site 12 South Landfill (Operable Unit 11). The ROD selects limited soil and sediment removal, on-site consolidation, soil cover, land use controls and long-term monitoring to address unacceptable risk to human health and the environment from metals, polycyclic aromatic hydrocarbons and dioxins present in soil. These actions will be protective by: eliminating the potential human and ecological exposure to contaminated soil and landfill waste material; minimizing the erosion of contaminated surface soils and transport of contaminated surface water; reducing the potential contaminant migration from buried landfill waste and contaminated soils into groundwater; improving site drainage and eliminating ecological exposures to contaminated sediment. Groundwater at this site will be addressed in a separate action. This ROD is a Federal Facility mission measure achievement for October.

Defendants (1)

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATIONNamed in complaintNamed in settlement

Facilities (1)

• WILLOW GROVE NAVAL AIR AND AIR RESERVE STATION

  ROUTE 611, WILLOW GROVE, PA, 190905348

  Registry ID: 110001001772

Statutes cited

• CERCLA 106A — Imminent & Substantial Endangerment Order
• CERCLA 120E — Federal Facility Interagency Agreement

Enforcement conclusions (11)

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION (OU11 Site 12 Southern Landfill)entered 2021-10-21

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION OU-4entered 2007-09-21

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION OU-12 (PFAS)entered 2017-11-30

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION (OU-2)entered 2012-09-25

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATIONOU-12 (PFAS)entered 2017-11-30

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION OU-02 (Site 5)entered 2015-09-29

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION (OU 12 PFAS Drinking Water Action Memo)entered 2025-09-30

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION (OU 12 PFAS GWETS AM)entered 2025-12-15

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION - (OU1)entered 2006-09-29

  Primary law: CERCLA

• WILLOW GROVE NAVAL AIR & AIR RESERVE STATION OU-12 (PFAS)entered 2018-06-19

  Primary law: CERCLA

Timeline (3 milestones)

• 2004-11-17Enforcement Action Data Entered
• 2005-06-27Complaint Filed/Proposed Order
• 2025-12-15Final Order Issued