ARFF vehicles are the main tool in airfield firefighting. In addition, there are a large number of DoD installations, including aircraft hangars and other storage and workplaces where fire protection is provided by foam delivery systems, many of which utilize AFFF as the extinguishment formulation. The DoD is estimated to have more than 6,000 ARFF trucks in its inventory and most of these trucks have been used with AFFF and are thus contaminated with PFAS. In ESTCP, we are exploring methodologies to clean these vehicles and foam delivery systems as water washing has proven to be ineffective, and we are also looking at appropriate technologies to dispose of rinsate from the cleaning process.