Building on the momentum of coal ash excavation work already underway at several Carolinas sites, Duke Energy last week recommended full excavation of an additional 12 coal ash basins in North Carolina.
The material would be safely reused in lined structural fills or permanently disposed in lined landfills.
The announcement brings to 24 the total number of Carolinas basins the company is prepared to close by removing ash from its current storage locations at each power plant.
The company recommends excavating five basins at the Cape Fear Plant in Moncure, North Carolina, five basins at H.F. Lee Plant in Goldsboro, North Carolina, one basin at W.H. Weatherspoon Plant in Lumberton, North Carolina, and one inactive basin at the Cliffside Steam Station in Mooresboro, North Carolina.
Most of the excavated ash from these basins would be relocated to previously discussed lined structural fills in Chatham and Lee counties in North Carolina.
"We're making strong progress to protect groundwater and close ash basins, delivering on our commitment to safe, sustainable, long-term solutions," said Lynn Good, Duke Energy's president and CEO.
"A blue ribbon national advisory board and independent engineers, scientists and dedicated teams at Duke Energy are spending thousands of hours studying data, building enhanced groundwater and surface water protection programs, and identifying closure options that protect people and the environment in a cost-effective manner," Good said.
The company is continuing to study the remaining 12 basins in North Carolina to identify smart and effective ways to close those facilities while minimizing overall environmental impact.
Based on engineering work completed to date, the remaining 12 basins could be candidates for a broader range of closure options, including an approach that consolidates the ash on-site, caps it with a durable and impermeable liner and protects groundwater.
However, work continues to inform those decisions, including comprehensive groundwater assessments, groundwater modeling and other site-specific engineering.
State and federal coal ash regulations allow various proven closure options based on each site's specific circumstances. Today's progress report comes after extensive study to ensure that the recommendations comply with the Environmental Protection Agency's recently published federal Coal Combustion Residual (CCR) regulations and North Carolina's Coal Ash Management Act (CAMA).
The proposals are subject to public input and approval by the North Carolina Department of Environment and Natural Resources and the North Carolina Coal Ash Management Commission.
Since October, a blue ribbon panel of international experts interested in safe and practical solutions for the disposal of coal ash has been reviewing the company's strategy and technical approach to closing ash basins.
The National Ash Management Advisory Board (NAMAB) is led by John Daniels, a former program director at the U.S. National Science Foundation and current professor and chairman of the Department of Civil and Environmental Engineering at the University of North Carolina at Charlotte.
Working with Duke Energy engineers and scientists, NAMAB developed a set of guiding principles for safe basin closure.
Technical or regulatory reasons led the company to recommend full excavation for 24 basins in the Carolinas thus far. These facilities are operating safely but are not suitable locations for the material long term.
"While conditions at each site are unique, our board has established a common set of principles for Duke Energy to apply to each closure option, ensuring compliance with state and federal laws," Daniels said. "We fully support this science- and engineering-based approach."
The company's approved plans and the latest recommendations for each ash basin in the Carolinas include:
- Continued excavation of coal ash at W.S. Lee Steam Station in Belton, South Carolina; Riverbend Steam Station in Mt. Holly, North Carolina; and the Asheville, North Carolina, Electric Generating Plant.
- Already planned excavation of coal ash at the Dan River Steam Station in Eden, North Carolina; L.V. Sutton Steam Electric Plant in Wilmington, North Carolina; and H.B. Robinson Plant in Hartsville, South Carolina.
- Recommended coal ash excavation at the Cape Fear Plant in Moncure, North Carolina; H.F. Lee Plant in Goldsboro, North Carolina; W.H. Weatherspoon Plant in Lumberton, North Carolina; and one basin at the Cliffside Steam Station in Mooresboro, North Carolina.
- Continued study to determine the best options for Allen Steam Station in Belmont, North Carolina; Belews Creek Steam Station in Belews Creek, North Carolina; Buck Steam Station in Salisbury, North Carolina; two basins at the Cliffside Steam Station in Mooresboro, North Carolina; Marshall Steam Station in Terrell, North Carolina; Mayo Plant in Roxboro, North Carolina; and the Roxboro Plant in Semora, North Carolina.
Depending on how quickly plans are reviewed and approved, Duke Energy is confident it can comply with North Carolina's deadlines to have all basins in the state safely closed by 2029. Individual basin closure timelines will be determined by the state's classification process and other factors.
In parallel with the work outlined above, Duke Energy also plans to add interim measures to further protect groundwater and surface water as needed before basins are closed, including:
- Capturing engineered seeps and rerouting the water back to the ash basins or other treatment systems, eliminating the flows. Seeps are common in earthen dams and do not affect water quality in nearby lakes or rivers. This work should be complete in the next six to 12 months.
- Developing engineering plans to address groundwater exceedances. The company will use the results of comprehensive site assessments to develop plans to remove water from basins and remediate groundwater to the extent needed.
Work will be prioritized based on the unique conditions at each facility and basin closure schedules.
"Once the assessments have been completed, well-established engineering solutions can be deployed as needed to enhance groundwater protection," Daniels said. "Moving forward, NAMAB will be independently reviewing the data and advocating for state-of-the-art closure plans that maximize beneficial use. The scale, scope and aggressive schedule of closure efforts that Duke Energy is undertaking allow these principles to serve as a guide for the entire industry."
Earlier this month, Duke reached a settlement with Virginia for a February 2014 spill of coal ash in North Carolina that floated down the Dan River, depositing tons of the toxic stew into the city of Danville's waterfront and beyond.