PFAS found in 72% of drinking water samples in Philly’s suburbs Frank Kummer, The Philadelphia Inquirer PFAS “forever chemicals” have been detected in 33 of 46 public water locations in Philadelphia’s suburban counties, or 72% of samples, although none exceeded totals of federally suggested limits, according to an Inquirer analysis of new state data. Statewide, however, the Pennsylvania Department of Environmental Protection found PFAS in only 35% of 114 sites tested in a broader sampling of 22 counties. Similarly, none of those exceeded the current EPA guideline of 70 parts per trillion, although some scientists contend there are no safe levels. The Inquirer looked at results for Philadelphia, Bucks, Montgomery, Chester and Delaware counties. The data indicate most PFAS samples were found in Bucks and Montgomery, though that was expected because of past contamination from military bases, and that’s where the state focused most of its effort.