Dam issues cited at Cliffside plant
A recent inspection of dams near coal ash basins at the Cliffside Steam Station yielded citations directed at Duke Energy from the North Carolina Department of Environment and Natural Resources (DENR).
The state’s Dam Safety Program conducted an on-site investigation of the two dams last week and concluded the “high-hazard” dams had deficiencies.
One deficiency was regarding a corrugated pipe which inspectors noted had deteriorated to the point of a noticeable increase in flow. A letter from DENR to Duke outlined the issue and stated “a makeshift system consisting of sandbags, PVC pipe and tanks to collect the flow from the barrel was in place at the barrel outlet.”
The ash basin dam was also reported to have “varying degrees of seepage and corrosion.” The report said “at least two of the drains have broken/corroded, separated portions of pipe lying on the dam toe (base).”
Inspectors said the problem warranted immediate mitigation from a registered professional engineer and “in the event of dam failure, significant environmental damage to the Broad River could occur due to release of coal ash stored behind the dam.”
In the reports, investigators noted Duke officials attempted to seal the break in the pipe with flowable fill cement but those attempts were unsuccessful. Investigators told Duke officials repairs must be approved by DENR before they are made.
However, DENR officials said there is nothing to indicate a potential for a coal ash spill similar to the Feb. 2 spill into the Dan River at Duke’s Eden facility.
“Our investigations have not turned up anything that would indicate that,” said Bridget Munger, DENR spokeswoman.
The spill into the Dan River was the result of a storm water pipe bursting under a coal ash pile, releasing nearly 80,000 tons of coal ash into the river. Officials said nearly 70 miles of the Dan River was affected by the spill near the North Carolina-Virginia border.
The other citation referenced vegetation on one of the dams being improper.
“There were issues with vegetation growing on the dam and grass growing on the crest of the dam,” said Jamie Kritzer, DENR spokesman. “Grass on the dam can prevent erosion but you don’t want trees — that could lead to internal erosion.”
The citation indicated trees and bushes growing on the dam which “can cause problems and even failure of the dam by creating holes when trees are uprooted due to wind or ice …”
DENR officials directed Duke to remove the larger vegetation and place grass on the dam.
Duke officials responded to the citations with an email to DENR from John Elnitsky, vice president of project management and construction.
“Duke Energy is in receipt of your letter and will reply as requested,” the email said.
The investigations into the Cliffside dams were part of a statewide inspection of all Duke’s facilities in the wake of the Dan River spill.
“We will take appropriate action to enforce the laws and protect public health and the environment to prevent another coal ash spill like the one that happened in Eden,” said John Skvarla, DENR secretary, in a release.
Duke has until April 7 to contract with a registered professional engineer and provide a plan to repair the Cliffside dams. DENR said, if that is not done, it “can take appropriate enforcement action.”