So-called “forever chemicals” have been found in 45% of the nation’s tap water, according to a recent government study, but is your tap water affected? If you’re wondering whether or not your tap water might contain synthetic chemicals known as PFAS, nonprofit Environmental Working Group created an interactive map using official records and data from public drinking water systems to show where forever chemicals were found to be above and below the advised maximum concentration level, 4 parts per trillion (PPT). … Sample sites in the 12-65 PPT range were found in and around Grass Valley, California; Fresno, California; Los Angeles; Lakewood, Colorado; … The USGS said most PFAS exposure was found near urban areas and potential chemical sources, with higher counts in the following regions: Great Plains, Great Lakes, Eastern Seaboard and Central/Southern/California.