Along 75 miles of the Ohio River – from Parkersburg, West Virginia, to Pomeroy, Ohio – water from wells contaminated with C8, or perfluorooctanoic acid, is being filtered through granulated activated carbon before reaching taps in homes and businesses.

That’s good. The chemical has been tied to a number of cancers and health disorders.

But what about the homes and businesses downriver from DuPont’s Washington Works plant south of Parkersburg? For more than 50 years, the plant spewed tons of the chemical directly into the river or into the air through its smokestacks.

Dr. Paul Brooks,who helped start a community health study to measure the level of C8 in the blood of Ohio and West Virginia residents living near the company’s Washington Works plant, said of areas farther downriver: “We were strongly recommending that these local water districts test for contamination in their drinking water, not just based on its bio-persistence, but the logic that it would flow down.”