The Air Force is using new guidance from the Environmental Protection Agency to determine if water at US bases and communities is contaminated, according to the Air Force Civil Engineer Center. Previously, the Air Force had followed guidelines issued in 2009 for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in drinking water, but will now follow updated guidelines issued May 19. USAF has tested for the chemicals at 30 bases, and has found them above the new EPA guidelines at 202 homes. Deputy Assistant Air Force Secretary for Environment, Safety, and Infrastructure Mark Correll said protecting health is the service’s priority, and stressed that when Air Force missions have had or are having “an adverse impact on communities,” USAF will take “appropriate measures.” The two chemicals are resistant to heat, water, and oil, and do not degrade easily. They are both used in a foam the Air Force and other agencies use to fight petroleum fires.