Study: Coal Ash Not Source Of Contamination In NC Wells

Oct 27, 2016

Researchers at Duke University have found widespread contamination of North Carolina well-water with hexavalent chromium. Researchers initially believed the cancer-causing toxin was coming from coal ash ponds. But Duke professor Avner Vengosh said his new study shows the dangerous compound is naturally occurring across the state.

"It's related to water-rock interaction that's causing, in some circumstances, the leeching out of chromium and converting it to hexavalent chromium," Vengosh said.

Hexavalent chromium, also known as chromium-6, is a carcinogen made famous by the Erin Brockovich case. The heavy metal has been linked to myriad health problems, including cancer.

Vengosh said his team found the toxin in wells many miles from coal ash pits, and that the technology researchers used allowed them to trace it to the natural geology of the Piedmont.

"In some wells we did we found relatively high values, and some folks should be concerned," he said.

Federal and state authorities are not required to test small, individual wells. That puts the responsibility on private well owners, who may not be aware of the danger or  have the means to test their wells.

"So I think the state should find resources and accommodate this need to conduct comprehensive monitoring of the level of hexavalent chromium in the drinking water wells of North Carolina," Vengosh said.

Duke Energy officials told the Charlotte Observer the findings are consistent with data that shows coal ash has not harmed private wells.

'This study is an extraordinary development, particularly for hundreds of plant neighbors who have been needlessly concerned that ash basins contributed hexavalent chromium or other substances to their wells,” Duke Energy's Senior Vice President of Environmental, Health and Safety Harry Sideris told the newspaper.

California is the only state that regulates chromium-6. In May, some North Carolina democratic state lawmakers tried and failed to pass regulations on chromium-6.

Vengosh adds that even though chromium-6 detected in well water is  not coming from Duke Energy's coal ash ponds, the ponds are still dangerous.

"When we see contamination of coal ash, we see a wide assembly of contaminants. We see arsenic, we see selenium, we see boron, strontium," he said. "Coal ash ponds need to be addressed as potential environmental and human health issues."