North Carolina environment officials are listening as plans settle for almost two decades of future coal ash cleanup at a Lake Wylie site.
On Feb. 27, the North Carolina Department of Environmental Quality will hold a public hearing on plans to excavate coal ash at Allen Steam Station on the northern end of Lake Wylie. The meeting will come a day after a similar hearing for excavation at Marshall Steam Station on Lake Norman. The Allen plant meeting wraps up a series of 10 such hearings related to the excavation of almost 80 million tons of coal ash at six Duke Energy sites, and recycling ash from four more.
Coal ash is a byproduct of coal burning at coal-fired power plants. According to the Environmental Protection Agency, coal ash can include anything from fine powdery silica to coarse ash, wet calcium sludge to a dry mix of silfites and sulfates.
Coal ash contains materials like mercury, cadmium and arsenic which can pollute waterways. Federal attention to coal ash sites — largely alongside public waters as are the coal plants that produce the ash — heightened following a 2008 spill in Tennessee where 5.4 million cubic yards of ash spilled over up to 300 acres outside a Roane County plant. Then, an estimated 39,000 tons of ash spilled from a Duke site in Eden, N.C. in early 2014.
Both spills reached public waterways.
The Allen site is on Lake Wylie, the drinking water source for much of York County. The Lake Norman plant is two reservoirs upstream. Duke officials say water supplies near and downstream from the sites haven’t been impacted by the ash and won’t be during cleanup.
“Their water supplies are protected now,” said Bill Norton, Duke spokesperson. “They’re going to stay protected.”
On Dec. 31, 2019, Duke reached a settlement with the state environmental department and several environmental interest groups to move forward with excavations at Allen and elsewhere. Duke submitted coal ash site closure plans as required by the 2016 Coal Ash Management Act in North Carolina.
“Everyone’s on the same page now,” Norton said.
The latest plan
Allen includes both an active and retired ash basin. The retired basin, active from the plant opening in 1957 until 1973, has about 8.9 million tons of coal ash. It has two embankments operating as dams. The active basin operated from 1973 to February 2019. It has about 10.5 million tons of ash. It also has two two embankments operating as dams, according to the Duke closure proposal.
“Allen has the most material we’ll have to excavate,” said Dave Renner, closure engineer for Duke.
Submitted plans have Duke excavating the ash and placing it in new, double-lined on-site landfills within the footprint of the current ash basins. Duke already started by dewatering the sites, but further work will come after final approval from the state environmental department, Renner said.
Based on various approvals and permits needed, it could be early 2023 before the first coal ash makes it into a new landfill. Able to secure 1.5 million tons of ash per year, Duke eyes completion by 2037.
The larger proposed landfill would be up to 110 acres. When completed, vegetation on top of the landfill would put it about 110 feet above nearby South Point Road. Neighbors, Renner said, will notice the earthen mound.
“It’ll be pretty prominent on their line of site,” he said.
The smaller landfill on the northwest corner of the property would be 30 acres. It’s closer to South Point, about 50 feet higher than the road, Renner said.
With almost two decades of what essentially will be a construction site ahead, managing potentially unsafe material right along the banks of a major water source, Duke faces challenges.
“Storm events are going to be one of our ongoing issues we have to deal with,” Renner said.
Rainwater that comes in contact with the site will have to be treated as ash water, though the site will have more capacity since most of the basin water will be removed before excavation. Today rainwater from about 200 acres of land would flow into the basin. There’s also a large power transmission structure that would have to remain stable during excavation. There’s the depth of material, in some places 60 feet deep.
“That actually puts it down below the level of Lake Wylie,” Renner said. “That’s going to present some challenges for us.”
Along with having the most coal ash of the various cleanup sites, he said Allen also has neighbors closest to it.
“There’s a couple houses here where, literally their back yard is the ash pond,” Renner said.
Still, Duke is confident work to put the ash in landfills can happen safely, Norton said. Below-grade pipes have been eliminated, water pumped out and new spillways installed in both basins. The submitted closure plan notes inspection, monitoring and maintenance required during a 30-year post-closure care period.
Keeping the new landfills on-site will help avoid hauling it out 20 tons at a time, Renner said, saving almost 2 million truck trips in the area. Some ash will have to be moved to make way for the landfills, before ash can then fill them.
Duke continues to evaluate ways not only to work safely on the closure, but work in a way that doesn’t disrupt the area around the plant.
“That’s a long, long window,” Norton said. “As best possible, we’re going to minimize impacts.”
The main challenge remains one from before Duke submitted its proposal for closing the basins. Norton said there’s a tendency to focus on groundwater as if drinking water supplies are unsafe.
“They have been safe all along,” he said.
Want to go?
The North Carolina Department of Environmental Quality public hearing on Duke Energy closure plans at Allen Steam Station begins at 6 p.m. Feb. 27 at Stuart Cramer High School, 101 Lakewood Road, Belmont, N.C. For more information or to submit online comments, visit this link.