Under the Dome

New well tests show naturally occurring contamination near coal power plants

UPDATED Tests of wells in the vicinity of Duke Energy coal-fired power plants — but not close enough to have been affected by their ash storage ponds — show contaminated water supplies, the state Department of Environment and Natural Resources reported Monday.

Duke Energy said the results from what is called background testing indicates that groundwater contamination found near the plants is naturally occurring and not the result of leaking coal ash basins.

“While the state’s background testing would have been helpful months ago, it does validate what we’ve been saying from the beginning,” Duke Energy spokeswoman Paige Sheehan said by email. “The constituents found in wells near our facilities occur naturally and at various levels across the state.”

This new round of tests expanded to wells that were far enough away from the power plant basins so that they would not be affected by them, in order to establish a baseline of what naturally occurs in those areas. DENR says that the recent samples are thought to be similar to the water quality conditions closer to the plants.

The 24 newly tested wells don’t meet current state groundwater nor health screening standards, but they are within federal drinking water standards. Still, the state issued “do not drink” warnings to 20 of the well owners; four well tests were incomplete.

The tests were conducted at the Allen Steam Station near Charlotte, the Buck Steam Station that straddles Davidson and Rowan counties, and the Marshall Steam Station in Catawba County.

Previously, nearly 300 private wells were tested around the state near power plants. The state issued do-not-drink warnings to owners. The drinking water well assessments are part of the Coal Ash Management Act enacted last year.

DENR, in a blog posted on its website, said the source of well contamination doesn’t matter in terms of the public health response. But DENR says it will require Duke Energy to provide alternative drinking water to well owners if they determine the wells were contaminated by coal ash spreading underground. There are 14 coal power plant sites in the state. The utility has already begun providing bottled water to some residents.

Duke Energy is concerned that the state has been confusing some well owners by reporting overly restrictive levels of contaminates while the water remains at federal safe drinking standards.

Sheehan said the results are encouraging but there is more work to do, including detailed groundwater assessment by outside experts.