Duke Energy last week assured South Carolina Public Service Commission members that the utility’s coal ash pits in the state were safe and designed differently from the one that failed at its Eden, N.C. plant, coating a 70-mile stretch of the Dan River in toxic sludge.
What the executives didn’t mention was the company had just been cited by South Carolina environmental regulators a month earlier for problems at its W.S. Lee Power Station along the Saluda River. The notice of violation from the Department of Health and Environmental Control said Duke failed to file critical monitoring reports for three years, and had problems with erosion and seepage around an earthen dam that holds back tons of coal ash.
“Duke simply did not tell the Public Service Commission the full story,” said Frank Holleman, a senior attorney with the Southern Environmental Law Center who gave his own briefing at the commission meeting.
Duke spokeswoman Paige Sheehan said in an email that the Lee station is “safe and inspected regularly by the company and outside agencies.”
But she didn’t immediately respond to questions about why Duke didn’t disclose the notice of violation to the commission at the meeting.
Jack Spadaro, an engineering consultant and former director of the National Mine Health and Safety Academy, reviewed the state’s notice of violation and Duke’s response for The Associated Press.
He said the letters reveal that there were “serious engineering problems regarding stability of the upstream slopes of the coal ash dams and that the factors of safety were too low.”
“The letters also indicate that some of the material used to construct the dams was very fine material that can fail under seismic loading caused by earthquakes,” Spadaro said.
There also was substantial erosion damage to the upstream slopes, he said.
But the most important thing: a stability analysis was not done on the dams as recommended by the EPA evaluations. “That study is still being undertaken, so long-term safety of the dams is questionable,” he said.
Duke requested the March 24 meeting with the Public Service Commission to let it know what happened at the Dan River plant and to give information about the South Carolina ash pits.
The regulators can review Duke’s rates and operations in the state, but approval of any plans on what to do with the ash pits would fall to the environmental agency.
Duke has ash pits at two power plants in South Carolina. The W.S. Lee plant, which is set to convert to natural gas within a year, has two. The other is at an already closed plant in Darlington County where the ash pit has dried up.
Mike Ruhe, the company’s director of environmental affairs in South Carolina, told the commissioners that the ash pits don’t have storm water pipes running under them and they will be thoroughly checked to make sure they are safe, according to the utility.
A break in a storm water pipe caused the leak into the Dan River with toxic sludge containing arsenic, selenium, lead and other contaminants.
“To the extent that the team finds any issues, we will aggressively address those issues or any potential risks,” Ruhe said.
But Ruhe and a Duke lobbyist who also talked to the commission didn’t bring up the recent violations at the Lee plant.
The state environmental agency said Duke failed to file its annual coal ash monitoring reports for 2011, 2012, and 2013. The company submitted those reports on Feb. 21 – just three days before the agency inspected the Lee pits.
During the inspection, regulators found erosion and other problems.
“Erosion must be repaired on the upstream slope of the secondary ash pond,” the state report said.
Inspectors also discovered “visible seepage” emerging from the toe of a slope on the second ash pit and told the company it must be fixed.
And the regulators said they had concerns about whether Duke had corrected problems cited in earlier inspections.
Duke responded in a March 11 letter that it would develop a plan to address the erosion and the company had implemented many of the earlier recommendations. It also said the dams were safe.
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