The North Carolina Department of Environmental Quality (DEQ) hosted a public information session Thursday regarding options to close the coal ash basin at Marshall Steam Station. The event was the third of six scheduled throughout the state near sites where coal ash impoundments are located.
Late last year, DEQ determined that Duke Energy met criteria established by the Coal Ash Management Act (CAMA) to classify coal ash impoundments as low-risk at six sites throughout the state, including Marshall Steam Station.
CAMA was enacted in 2014 after approximately 39,000 tons of coal ash spilled into the Dan River from a broken pipe at the now closed Dan River power plant in Eden. The spill occurred a year after DEQ filed lawsuits alleging Duke Energy violated state law by unlawfully discharging and groundwater contamination. The act forced Duke Energy to provide a permanent alternative water source to residents surrounding coal ash sites and repair dams at facilities around the state.
According to a Duke Energy notice of groundwater protection standard of exceedance released in October, arsenic, beryllium, cobalt, lithium, thallium and radium 226 and 228 combined were detected at levels above protection standards.
Approximately 20 million tons of coal ash is stored at Marshall, separated from Lake Norman by an earthen dam that is permeable, allowing water to move through the coal ash into the lake. According to Catawba Riverkeeper Brandon Jones, the seepage isn’t enough to show up in water samples from the lake, but contaminants have been found in groundwater near the basin and in fish. Currently, there’s a public health advisory in place on striped bass and hybrid striped bass due to bioaccumulated mercury and polychlorinated biphenyls.
The coal ash basin at Marshall Steam Station is nearly six miles, as the crow flies, from the Lincoln County Water Treatment plant on Tree Farm Road, which does testing for metals.
Jones said he wouldn’t expect the contaminants to pose a risk even if there was a spill.
“Lake Norman is so big and the distance is so far,” Jones said. “These particles generally bind with the soil. I wouldn’t say it’s a risk for municipal water, but certainly a risk for people with wells right beside it.”
The reclassification to low-risk status means Duke Energy has three closure options for cleaning the sites. DEQ will decide whether to require Duke Energy to excavate and remove the material or cap it in place.
According to the DEQ’s Marshall Station Ash Basin Closure Options analysis summary report, the first of the three closure options is to excavate the coal ash and move it to a consolidated closure area on site. The option includes adding a stability feature and capping with an infiltration cover system. It would reduce the current basin’s footprint by 184 acres.
The second option would require Duke Energy to excavate all coal ash materials and one foot of residual soil within the basin’s footprint. The materials would be moved to a lined onsite landfill. According to the report, the new landfill would rise 175 feet and would be capped with an infiltration barrier system.
The final, and most disputed option known as cap in place, would cap the basin with an infiltration barrier system. This option leaves nearly 20 million tons of coal ash in place on Lake Norman.
The site, along with 23 other basin at 14 Duke Energy sites, is in violation of the the Coal Combustion Residuals (CCR) rule. In the CCR rule filing by Duke Energy in September 2018, the coal ash basin at Marshall doesn’t the meet the requirement that the base of the basin be no less than five feet above the top of the uppermost aquifer nor does it meet the wetlands impact requirements. However, the EPA announced in July that it plans to replace the CCR rule with less demanding regulations.
According to its website, the Catawba Riverkeeper advocates for ash to be stored in lined landfills that meet federal guidelines or recycled into building materials. They say if capped in place, the unlined basins will continue to be a risk to groundwater and threaten surface water.
Regardless which option the DEQ decides for remediation of Duke Energy’s coal ash basins, construction costs could exceed $1 billion initially, not including maintenance. According to the DEQ’s analysis report of Marshall’s closure options, construction of any of the options could take 15-30 years. However, excavations at the smaller Riverbend Steam Station in Mt. Holly were completed in under five years.
CAMA rules require a decision by December but DEQ is expected to announce a decision in April.
Jones calls these meetings the best chance for the public to input on this decision.
“Once DEQ makes a decision, they’ll take comments about it, but it’ll be very difficult for them to change their minds,” Jones said.
The next meeting in the Catawba River Basin is Jan. 29 at 6 p.m. at Stuart Cramer Middle School located at 101 Lakewood Road in Belmont.