SOUTHEASTERN NORTH CAROLINA (WECT) - After news that Chemours would stop discharging the chemical GenX into the Cape Fear River, WECT has learned about another contaminant in our water supply.
Scientists testing Cape Fear River water who discovered GenX also found elevated levels of a chemical called 1,4-dioxane. 1,4-dioxane is an emerging contaminant that has caused liver and kidney damage to laboratory rats chronically exposed to 1,4-dioxane in their drinking water.
In studies of workers exposed to the compound through their jobs, there was no conclusive link to cancer. Still, the EPA has determined 1,4-dioxane to be a "probable human carcinogen."
The compound is an industrial solvent found in paint strippers, varnishes, soaps, make-up and antifreeze. It is one of 30 chemicals the EPA has identified as needing to be tracked and studied, with the goal of eventually regulating those that pose the greatest risk to public health.
While GenX is one of about 100 known emerging contaminants, it did not make this list of those found most pressing to be studied for their potential health risks like 1,4-dioxane did.
Dr. Detlef Knappe, an NC State researcher who partnered with environmental regulators to study our local water supply, says news that Chemours would stop discharging GenX into the water supply was "encouraging" but he still has other concerns.
"One question I have is whether the new management approach will also be effective in preventing the release of the other perfluoroalkyl ether carboxylic acids we have been finding at concentrations that greatly exceed those of GenX," Knappe told WECT. While 1,4-dioxane is not a perfluoroalkyl ether carboxylic acid, Knappe said it is also present in the river in greater concentration than GenX.
According to the DEQ, removal of 1,4-dioxane through traditional water and wastewater treatment methods is ineffective. Knappe said elevated levels of 1,4-dioxane have been found in both the Cape Fear Public Utility Authority water system and the Brunswick Regional water system as recently as 2015.
The North Carolina Department of Environmental Quality (DEQ) has been studying 1,4-dioxane in the Cape Fear River basin for the last two years. The DEQ considers .35 parts per billion to be a safe contaminant level, but water samples taken as recently as the fall of 2016 show the average level of 2 at Lock 1 in the Cape Fear River near Kelly, about 6 times the safe level of 1,4-dioxane.
Some parts of the state had even more alarming levels in their water supply. In the Haw River at Troxler Mill Road near Reidsville, researchers found average levels of 1,4-dioxane at 351 in the first year of testing, more than 1,000 times the EPA safe level. In the second year, 1,4-dioxane levels there had dropped considerably, to 11.
In the Cape Fear River Basin, the DEQ identified four primary areas of elevated 1,4-dioxane in the upper portion of the basin. Those are the Cape Fear River at Harnett County Public Utilities intake, Cape Fear River at US-401 at Lillington, Cape Fear River at Hoffer WTP intake at Fayetteville, and the Lock in Kelly mentioned above.
"Three of these areas were located immediately downstream of domestic wastewater treatment facilities, indicating that these facilities were likely conduits for 1,4-dioxane from industrial sources into surface water. The fourth was located further downstream of a wastewater facility, as well as in proximity to potential legacy sources of the contaminant," the DEQ explained in a report about its study.
For now, these "emerging contaminants" continue to go largely unregulated as scientists try to gather more definitive evidence about their effects on humans.
Stay tuned for more on this developing story as we get more information from state regulators.