DuPont has known since 1984 that its chemical plant in Parkersburg, West Virginia, was polluting local water supplies in nearby Washington County, Ohio, but did not tell local residents or do anything to correct the problem, according to environmentalists and a water district suing the company. DuPont’s Washington Works Plant has caused a chemical used to make Teflon to leach into underground wells used by local residents, claims the Little Hocking Water Association. The Environmental Working Group reported that DuPont secretly tested wells 25 years ago and discovered contamination involving perfluorooctanoic acid