PFAS Study Brad Geisman and Dan Casey discuss a water treatment system being used to remove per- and polyfluoroalkyl substances, or PFAS, from groundwater at the fire training area of Wright-Patterson Air Force Base, Ohio on Sept. 29, 2020. SHARE: Download: Full Size (0.1 MB) Tags: PFAS Credit: Ty Greenlees, Air Force VIRIN: 200929-F-AU145-1068.JPG Photo Gallery