The U.S. Environmental Protection Agency and DuPont have agreed on when the chemical maker must provide alternative water supplies to residents living near a West Virginia plant.
In an order announced Thursday, EPA's Region III said DuPont will provide alternative supplies when concentrations of a chemical used to produce Teflon hits 0.4 parts per billion. The previous level was 0.5 ppb.
EPA says the agreement currently affects 14 residents living near DuPont's Washington Works plant near Parkersburg.
A settlement in a class-action lawsuit involving the chemical required DuPont to install a filtering system on public water plants in Ohio and West Virginia. The company also is funding a health screening to determine if the chemical affects human health.