Initial sampling results of GenX in drinking water are in. They show that levels of the chemical far exceeded new — and drastically reduced — health department goals before Chemours stopped discharging most of its contaminated wastewater into the Cape Fear River.
After water from the Cape Fear had been treated by public utilities, levels ranged from a high of 1,100 parts per trillion to as low as 269 ppt, but all above the NC Department of Health and Human Services’ new health goal. State health officials announced late this afternoon that it had revised its recommendation for GenX in drinking water to no more than 140 parts per trillion, particularly for vulnerable people such as bottle-fed infants.
Originally, DHHS had said levels of GenX at 70,000 parts per trillion presented a “low risk” of health effects, based on Chemours data from 2013-2014. Although a safe level has not been established, the international threshold is 90 ppt; the EPA has set a “health advisory” for combined levels of PFOAs above 70 ppt.
A cancer risk is not factored into the 140 ppt threshold. DHHS said there are no studies in humans on cancer related to GenX. Only one animal study is available. While it did show increases in some cancers of the pancreas, liver and testicles, the EPA has not identified a specific level of GenX that could be associated with an increased risk for cancer.
Although there is no standard for GenX exposure in recreational use, the department also advised people not to swim in the area of the Cape Fear River near the Chemours plant in Fayetteville.
DHHS said in a press release that after it consulted with the EPA, a different set of animal studies and an uncertainty factor lowered the level from 70,000 parts per trillion to 140 ppt. The department emphasized that this updated risk assessment “is not final” and is likely to be updated when new information becomes available or the EPA sets standards.
When Chemours stopped discharging most of its wastewater into the Cape Fear, the levels dropped at the five public utilities: International Paper, Northwest Brunswick, Pender County No. 421, Cape Fear Public Utility Authority, Sweeney plant and Bladen Bluffs.
At that point, only the Pender wastewater treatment plant reported levels in drinking water above 140 ppt. A well at Wrightsville Beach recorded levels of just 24–26 ppt.
DEQ collected water from 13 sites, including areas in the river and at downstream wastewater treatment plants, on June 19 and July 6. The EPA office in Research Triangle Park and Test America, a Colorado-based lab, analyzed the samples. The higher levels occurred before Chemours stopped discharging most of its GenX-contaminated wastewater into the Cape Fear. (The plant still discharged smaller amounts until this week.)
June 19 sampling results indicated that at the Chemours outfall — basically where the discharge leaves the facility — levels ranged from 21,760 ppt to 39,000 ppt. By June 26, those levels had dropped to 15,250 to 19,000. Those were still higher than expected. A subsequent DEQ inspection showed areas in the plant that were still discharging GenX. Those parts of the facility have since been shut down.
Additional sampling occurred Wednesday and Thursday, although the results aren’t in. DEQ will also sample on July 17 and 24.
GenX, used in the manufacture of Teflon and other non-stick coatings, is an emerging contaminant. That means it has not been independently tested for safety; nor is it regulated.