North Carolina’s governor says he’s directing state criminal investigators to see if a chemical plant violated any permits by discharging a lightly studied chemical into a river hundreds of thousands of people use for drinking water.

Gov. Roy Cooper revealed his directions to the State Bureau of Investigation while speaking Monday to local officials in Wilmington.

Cooper also promised chemical company Chemours will be barred from releasing the compound known as GenX into the Cape Fear River alongside its Bladen County plant, which employs nearly 1,000 workers. The chemical is used to make nonstick products like Teflon, replacing a different chemical tied to increased cancer risk.

Cooper spokeswoman Sadie Weiner says the compounds are related and the health effects of GenX largely unknown.

Chemours didn’t respond to messages seeking comment.