Green Scene: Dam your ash

Kiss our ash goodbye?: An earthen dam holds back the coal-ash ponds at Progress Energy’s Skyland plant; the French Broad River and Interstate 26 lie below the 90-foot wall. photo by Hartwell Carson; flight courtesy SouthWings.
Kiss our ash goodbye?: An earthen dam holds back the coal-ash ponds at Progress Energy’s Skyland plant; the French Broad River and Interstate 26 lie below the 90-foot wall. photo by Hartwell Carson; flight courtesy SouthWings.

A coalition of local and national environmental groups announced plans Jan. 19 to sue the U.S. Environmental Protection Agency to force the release of long-awaited rules regulating coal ash as hazardous waste. Despite evidence of leaking ponds and poisoned ground water, the EPA has delayed issuing new rules for nearly two years.

Meanwhile, local environmentalists have recently urged Progress Energy to create a lined, capped, dry-storage facility for the coal ash produced by its Skyland power plant. This would help prevent toxins from leaking into the environment, and perhaps head off a massive spill like the one that flooded Kingston, Tenn., in 2008 (see “Coal Slurry for a Tennessee Christmas,” Dec. 23, 2008 Xpress).

Produced when coal is burned to generate electricity, coal ash contains varying levels of such toxic compounds as arsenic, mercury and chromium. At Progress Energy, scrubbers in the stacks capture up to 93 percent of the waste to keep it from going into the air. Instead, it’s sent to one of two large holding ponds, whose contents are held back by an earthen dam situated above Interstate 26 and the French Broad River.

Nearby residents have complained about ash blowing into their yards and open windows from the unlined, open ponds (see “When the Dust Settles,” Sept. 28, 2010, Xpress). And recent testing by the state Division of Water Quality found excessive levels of heavy metals including chromium and thallium in monitoring wells the agency maintains at the plant.

“We’re definitely seeing exceedances. … So now we’ll go to Progress Energy and begin the conversation,” says state hydrogeologist Brett Laverty. “This is not a small facility,” he adds. “This is a big gorilla: These facilities have been here for a very long time.”

There are no known drinking-water wells in the vicinity, but “We’ve asked [Progress Energy] to double-check using a well-receptor survey on the whole west side of the coal-ash basin,” says Laverty. “We’ve let them know that if they don’t do that survey, the Division will.”

Local environmentalists see a ready solution: “We need to get those ponds lined and covered,” says Judy Mattox of the WENOCA Sierra Club. It’s not clear how this would be achieved, however.

“Dry-storing these ponds is not going to be cheap or easy,” says French Broad Riverkeeper Hartwell Carson, a party to the EPA suit, “but it’s the only real solution. Until they eliminate the source, it’s not going to go away.”

Both Laverty and Progress Energy spokesperson Scott Sutton say there’s not enough room to create a new dry-storage facility on-site. “I don’t know what a proposal would look like,” Laverty reports, “but it’ll begin with us sitting down with Progress Energy and looking at the data.”

“There’s no way to control how ground water interacts with the [ponds],” he continues. “With dry-ash landfills, you’re excluding ground water from your coal ash, because you’re encapsulating it. It’s easily controlled, easily monitored.” As things now stand, however, “We’ve got a huge gorilla there.”

Margins of safety

The problem is twofold: contaminants seeping into ground water and the structural integrity of the dam. Built in 1964, the older of the two holding ponds is now inactive; the second one came online in 1982. Last October, the U.S. Environmental Protection Agency released a report listing the older pond’s condition as “poor,” meaning either that remedial action is necessary or that critical studies are needed to characterize structural deficiencies.

Meanwhile, the EPA has also rated the dam “high hazard,” due to the potential destruction and loss of life if it failed.

Progress Energy has proposed upgrading and stabilizing the dam; Sutton says the public isn’t at risk, “but we don’t have the excess margin of safety the Corps of Engineers recommends.”

To get the “poor” rating removed, he explains, the company must re-engineer the dam’s slope; that project is awaiting state approval. “The state knows the ball is in their court.”

As for the contamination, Sutton says it could be the French Broad River depositing heavy metals in the floodplain, where one of the monitoring wells is located. Other wells also showed excessive heavy metals, however.

“If there’s a need for mitigation,” says Sutton, “We’ll do that in lockstep with our regulators.”

North Carolina doesn’t currently require dry storage of coal ash, but that would change if the EPA reclassifies it as hazardous waste.

“We’ve invested big-time money in environmental controls at the Asheville plant,” adds Sutton. “It’s one of the three big plants that we’re not retiring from our fleet, because we’ve invested so much money in making it one of the cleanest plants in terms of emissions in the nation.”

It’s true that the scrubbers the company added to the waste stacks in 2005 have significantly cleaned up emissions. But how the Skyland plant stacks up nationally depends, in part, on which substances you’re looking at. According to just-released EPA data, the Asheville Steam Plant emitted some 2,400 metric tons of greenhouse gases (CO2, methane and sulfur dioxide) in 2010 alone, placing it in the bottom third nationwide for those emissions.

Sutton also stresses the Asheville plant’s critical role in the region’s power supply, serving customers in nine counties.

In the meantime, the utility inspects the dam regularly, in addition to the state’s annual inspections. “The idea is to catch small problems before they become big,” Sutton explains.

He also cites significant differences between this dam and the one that failed at Kingston. Progress Energy’s dam is made of clay; the Kingston dam was built from coal ash. “Then they had excessive rain. And they’d built a new ash pond on top of an older pond — another bad move.”

So what would it take to secure the coal ash in a lined, capped facility?

“Regulatory certainty,” says Sutton. “Right now, there’s substantial uncertainty: EPA is still considering whether to classify coal ash as hazardous waste.” At this point, he argues, it would be imprudent for any business to launch such a time- and money-intensive process.

“It would be tens of millions of dollars. We’re a regulated business; we don’t yet know the rules of the game.”

— Send your local environmental news and tips to sandrew@mountainx.com, or call 251-1333, ext. 153.

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