The state’s health advisory goal of 140 parts per trillion for GenX in drinking water is based on sound science, an advisory board concluded yesterday, while cautioning it doesn’t define a “boundary line” between a “safe and dangerous level” of the chemical compound.
The Secretaries’ Science Advisory Board issued a final draft of its report after nine months’ of public meetings, scientific debate and consultations with other states and countries about their handling of GenX and other fluorinated compounds. A finalized version of the document will be released soon for a 30-day public comment period.
The state might need to revisit the 140 ppt benchmark, said board chairman Jamie Bartram, after the EPA releases its own findings, which is expected to happen next month.
The report notes that drinking water composes only 20 percent of a person’s exposure to GenX; the remaining 80 percent comes from other sources, including microwave popcorn bags, fast food wrappers, non-stick cookware and water-repellant clothing.
That’s little consolation to thousands of residents in New Hanover, Brunswick, Robeson, Bladen and Cumberland counties whose drinking water has been contaminated by Chemours. A spinoff of DuPont, the company is responsible for discharging GenX into the Cape Fear River, which for nearly 40 years contaminated the waterway and the drinking water of downstream and nearb residents. Spills and discharges at the plant also contaminated the groundwater, which then migrated offsite.
Fluorinated compounds emitted into the air from the Fayetteville Works plant also contaminated the soil, fish, honey and groundwater miles from the plant. This occurred through a process known as atmospheric deposition, in which the compounds ride on air emissions, then mix with water, such as rain, and fall to the ground. From there, the pollution can enter drinking water wells, lakes, gardens — whatever lies in its path.
The board also recommended that DEQ and DHHS collaborate with the state agriculture department to determine whether to establish scientific standards for GenX in food. In addition, DEQ should also study the cumulative effects of the various fluorinated compounds on human health, ecology and the environment, the board said.
Last year, the state Department of Health and Human Services originally established a provisional health goal of 70,000 ppt for GenX in drinking water. State toxicologists set that benchmark based on one rodent study — the only peer-reviewed one they could find. After consulting a second time with the EPA, DHHS officials obtained a second study that prompted the agency to lower the threshold to 140 ppt.
The lack of peer-reviewed science about the health and ecological effects of GenX and other fluorinated compounds has stymied many state agencies, as well as the EPA, in setting definitive and enforceable contaminant levels in drinking water. There are no maximum contaminant levels for GenX in air, food, groundwater and soil.
However, the state Department of Environmental Quality does have what is known as a Practical Quantitation Limit, often referred to as PQL, of 10 ppt for GenX in groundwater. The “PQL” is defined as “the lowest concentration of a given material that can be reliably detected by routine lab analysis.
Since groundwater sampling at the Chemours plant showed concentrations of 64,000 ppt, the state has used the PQL to file a complaint in Bladen County against Chemours, asking a judge to force the company to legally stop all discharges of the chemical. The complaint also asks the court to require Chemours to pay for new wells and alternate drinking water supplies for affected residents.
Within the hundreds of pages of public comments on the complaint, though, residents demand that DEQ and the judge levy stricter enforcement and penalties. Those include shutting down all operations at the plant, either temporarily or permanently, and requiring Chemours to provide alternate water supplies to all residents whose drinking water tests above 10 ppt — the PQL — not just 140 ppt, the health advisory goal.
Commenters also asked that the state require Chemours to clean up and stop discharging any fluorinated compounds, of which there are thousands. Many of those compounds have been phased out, but because they persist in the environment, are still being detected not only in the Cape Fear, but in Jordan Lake and Lake Michie. These compounds have also been detected in drinking water wells at and near military bases, and in Greensboro’s water supply, most likely the result of runoff of firefighting foam from neighboring airports.