There is no measurable amount of C8 flowing from taps in the six Ohio River water districts that settled a lawsuit with DuPont over the toxic chemical that the company used to make Teflon.

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.

Some water-district managers along those 230 river miles say they will wait to see what regulations are added, or cut, by the Trump administration. Other managers say they don't think their water is contaminated, or they have more important things to worry about.

But Dr. Paul Brooks said of those districts, "We believe they are in danger of C8 contamination."

Brooks is a retired general practitioner 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. The study found that, in general, area residents had a median level of 38 parts per billion of C8 in their blood — 7.6 times more than the average American.

The $70 million study, financed by a DuPont settlement in 2005, was the foundation of a science panel's investigation that concluded a "probable link" existed between C8 and six diseases: kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, pregnancy-induced hypertension and high cholesterol.

Brooks 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."

Portsmouth Water Manager Sam Sutherland said the city doesn't plan to test for C8, which is an unregulated compound. He wants to see what the U.S. Environmental Protection Agency does under the Trump administration.

"We’re kind of waiting to see if they adopt guidelines for testing," Sutherland said. "If so, we’ll certainly test for it."

Nearby, Scioto Water's wells are close to the river but buffered by so much silt that most groundwater enters wells from the northeast, said General Manager Jeff D. Spradlin.

The well fields in Point Pleasant, West Virginia, tap into an aquifer that flows beneath the Ohio River, said Steve Gardner, operations manager for the city's waterworks. “Our well fields are so far from the riverbanks."

C8 showed up once in the Gallia County Rural Water Association system, but it was an odd reading, said General Manager Brent Bolin. It was detected in the system, but not where the water enters the plant and is treated.

"We test for everything we’re required to," Bolin said. "I do care, but I've got people drinking out of rain barrels. I have people drinking out of creeks next to where they change their oil."

Brooks said that's not the right attitude for suppliers of public water to deal with C8.

"That's not for them to decide," he said. "This is a public hazard, and it's for real. This stuff kills people over time."

Communities must put heat on politicians to do something, said Brooks, an adviser to Keep Your Promises, a grass-roots organization that wants to hold DuPont accountable for the effects of C8 on the Mid-Ohio River Valley.

The largest urban area along this stretch of the river, Cincinnati and northern Kentucky, has been using powdered carbon and activated carbon filtration systems for decades.

The Ohio River Valley Sanitation Commission is an eight-state cooperative that monitors the health of waterways in the Ohio River Basin, from New York to Illinois.

"We don’t routinely monitor for that," Jason Heath, the commission's manager of technical programs, said of C8. "We did a very limited study in 2009 on the Ohio River, random samplings in 20-some locations."

The highest level was at Ravenswood, West Virginia, where 0.0352 parts per billion were discovered, according to the report. (One part per billion is less than a teaspoon of water in an Olympic-size swimming pool.)

This month, the EPA lowered its "action level" for C8 in drinking water to 0.07 parts per billion. At that level, DuPont must provide drinking water to residents who live near the Washington Works plant.

DuPont and the EPA declined to comment on the C8 issue.

The level of C8 in the water and blood of residents and DuPont workers has been debated in the three C8 lawsuits that have gone to trial among more than 3,000 pending. DuPont has lost all three, including a $10.5 million award for punitive damages on Jan. 5 for a man who argued the chemical caused his testicular cancer.

The fourth such trial is to continue this week before U.S. Chief District Court Judge Edmund A. Sargus Jr. in Columbus.

A major point argued by plaintiff attorneys is the bio-persistence of C8. It doesn't go away, they say; it stays in your blood.

Brooks said of a typical 60-year-old: “If you had a level of 200 (parts per billion) in your blood today when they put out the filters, and you have no more exposure, you couldn’t live long enough to get rid of it. You’re not out of the woods until it’s out of your body.”

DuPont used C8 for so long that “it might take 200 years to get it out of the wells,” Brooks said.

Prosecutors in the Netherlands have begun a criminal investigation into possible C8 contamination from a DuPont plant there.

“It’s probably the worst contamination the world has ever seen,” Brooks said of C8 in general.

His partner in the health study was Dr. Alan Ducatman, professor of occupational and environmental health sciences at West Virginia University. Ducatman said he has received calls from communities asking for information about C8, "but not from communities on the Ohio River or anywhere near it."

"There's an irony that in places away from West Virginia and Ohio, people have been more successful in attracting a higher degree of concern, for whatever reason," he said.

erinehart@dispatch.com

@esrinehart