Brad Geisman, left, pilot engineer, and Dan Casey, lead field operations engineer for Emerging Compounds Treatment Technologies (ECT2), discuss the patented regenerable ion exchange (SORBIX RePURE) water treatment system being used to remove per- and polyfluoroalkyl substances (PFAS) from groundwater at the fire training area of Wright-Patterson Air Force Base, Ohio on Sept. 29, 2020. U.S. Air Force personnel from the Air Force Civil Engineer Center are leading the study of combining proven remediation techniques that can remove PFAS with new destruction technologies to destroy the PFAS. PFAS are a group of chemicals, some of which were formerly used in aircraft fire fighting foam. (U.S. Air Force photo by Ty Greenlees)