3M Co., E.I. DuPont de Nemours Inc., Chemours Co., and Corteva Inc. are facing a suit by Golden State Water Co. over PFAS contamination of the state water supply. The water supplier seeks to recover from 3M as the only manufacturer of perfluorooctanesulfonic acid in the U.S. PFOS and perfluorooctanoic acid are both in a family of chemical compounds known as per- and polyfluoroalkyl substances.