“The Duke researchers who discovered trace amounts of contaminants in water sources around the Triangle last year think they may be closer to understanding where they’re coming from. The potentially toxic contaminants, known as perfluorinated chemicals, or PFCs, are known to be especially elusive and difficult to track.

But at a forum last month sponsored by the Sierra Club and N.C. Central, Lee Ferguson, an environmental analytical chemist at Duke University, said that his team might have some ideas. In some cases, the chemicals could be coming from sewage that is recycled and used for agriculture. The repurposed sewage can flow into tributaries of larger bodies of water. And since wastewater treatment plants aren’t accustomed to looking for these little-known compounds, they’re not especially good at removing them from drinking water. In other cases, the chemicals could be carried through rainwater or the air.

Durham’s assistant director of water management, Vicki Westbrook, announced that Durham’s latest tests showed low levels of PFCs in the water. However, Westbrook doesn’t believe that they’re coming from water runoff but rather “some sort of aerosolized deposit that’s floating over when it rains, and it ends up there.”

Ferguson and his colleague, Heather Stapleton, collected water samples from various sources, including their home faucets, last year. Most contained detectable levels of fluorinated organic chemicals referred to as PFOAs and PFOSs, which the Environmental Protection Agency says cause cancer, liver damage, and birth defects, among other possible health issues, at high enough levels. It’s important to note that while Ferguson and Stapleton discovered these chemicals, they did so at levels well below what the EPA considers dangerous.

However, the combined level of a broader range of chemicals collectively known as PFAs, for which the EPA has not yet written a health advisory, was substantially higher in Cary and Jordan Lake. Ferguson says that’s at least cause for further investigation.

Rachel Monschein, a laboratory supervisor for the town of Cary, won’t speculate on the source of the PFAs but says that her team has been in touch with the scientists who discovered them.

A great deal of attention has been paid to GenX, a PFA that was recently discovered along the Cape Fear River. Created as a supposedly safer alternative to its predecessors, GenX was found emanating from the Fayetteville plant of Chemours, a spinoff of DuPont that manufactures Teflon and other nonstick coatings. The chemicals had likely been discharging as a byproduct since the 1980s. N.C. State is exploring the effects of the contaminant on residents in the Wilmington area, where the chemical has been frequently detected in drinking water.”

Read the full article by Nick Gallagher.