State data show contaminated groundwater near all 13 N.C. coal-ash ponds owned by Duke Energy and Progress Energy, an environmental group said Tuesday.
Ash, left by coal-burning power plants, is loaded with metals that can be toxic at high levels. It's often mixed with water and piped into open basins, a practice under scrutiny since a ruptured dike in Tennessee spilled 5 million cubic yards of sludge in December.
The analysis by Boone-based Appalachian Voices shows ash can also seep into groundwater and, the group said, also needs more oversight by regulators. The report detailed 681 instances in the testing of the ponds in which pollutants exceeded state groundwater standards.
Duke and N.C. groundwater officials didn't challenge the group's analysis. But they said there's no evidence that contaminated groundwater is flowing off the large, rural power plant sites into neighborhoods where people could be exposed to it.
"Based on the data we have, we do not believe we have any potential impact on public health or the environment," said Dave Mitchell, Duke's managing director for environmental issues.
Upper Watauga Riverkeeper Donna Lisenby, who is affiliated with Appalachian Voices, disagreed.
"I think it's probably much worse than anyone suspects," said the frequent Duke critic, a former Catawba Riverkeeper based in Charlotte. "If a truly independent analysis was done, not by the power companies, it would show much more serious contamination."
The Appalachian Voices analysis is based on pond data Duke and Progress Energy submitted to the state in April. It found arsenic, boron, cadmium, chloride, chromium, iron, lead, manganese and sulfate at levels higher than the state considers safe.
Arsenic ranged up to 12 times higher than the state standard, Iron 380 times higher and manganese 208 times higher.
Iron and manganese occur naturally in high levels in the N.C. Piedmont, Duke noted. Arsenic has been found at high levels, apparently naturally, in some places.
State officials said there's no evidence the coal-ash readings pose an eminent public danger. They aren't even sure the high contamination readings are illegal.
"At this point, the jury is still out," said Ted Bush, the state's aquifer-protection chief. "We don't know definitively, and we're convinced no one knows, whether these groundwater exceedances are violations that are enforceable."
The reason: State law allows groundwater contamination inside a "compliance boundary" 250 to 500 feet around an ash pond.
Duke acknowledges that the groundwater it tested was contaminated above state standards, mostly from the ash ponds. All the high readings were from inside the compliance boundary. But the utility has no wells on the boundary itself that might show whether contamination has spread.
Duke said the data it has collected so far doesn't indicate a need for the more distant wells, and the state hasn't required them.
The EPA now says it will propose tightening regulation of coal ash by late this year.
