The Pentagon may be forced to follow new state environmental pollution standards for a family of manmade “forever chemicals” that may have been spilled at hundreds of military sites in the U.S., Defense Secretary Mark Esper told lawmakers. Esper was pressed Wednesday at a House Armed Services Committee hearing over the military’s use of widely used firefighting foam containing chemicals known as per- and polyfluoroalkyl substances, or PFAS, that never degrade.