RALEIGH, N.C. (WGHP) — The nine remaining North Carolina coal ash basins will close now that state regulators and community groups have reached a deal with Duke Energy.

Duke Energy, North Carolina’s Department of Environmental Quality and the Southern Environmental Law Center announced Thursday that six of the basins will be excavated with the ash moving to lined landfills.

DEQ touts the plan as the largest coal ash excavation in the nation’s history.

“North Carolina’s communities have lived with the threat of coal ash pollution for too long,” said DEQ Secretary Michael S. Regan. “They can now be certain that the clean-up of the last coal ash impoundments in our state will begin this year. We are holding Duke accountable and will continue to hold them accountable for their actions as we protect public health, the environment and our natural resources.”

The plan involves the excavation of almost 80 million tons of ash across six facilities and will bring an end to pending court cases.

Duke Energy praised the deal for reducing the cost of the cleanup. The company previously suggested it would need to increase costs for customers to offset the cost of the cleanup process as outlined in earlier demands.

“This agreement significantly reduces the cost to close our coal ash basins in the Carolinas for our customers, while delivering the same environmental benefits as full excavation,” said Stephen De May, Duke Energy’s North Carolina president. “We are fully focused on these important activities and building a clean energy future for the Carolinas.”

The company assures that the groundwater in those areas is safe and will be monitored.

“Drinking and recreational water supplies are safe now, and Corrective Action Plans will address groundwater at each site to ensure those supplies remain protected,” the company said.

The plan involves the excavation of almost 80 million tons of ash.

The announcement comes after months of conflict over the future of the remaining basins.

For decades, Duke Energy had mixed coal ash from its facilities with water and stored the mixture in open ponds.

After a 2014 spill dumped 39,000 tons of ash from the Dan River plant in Rockingham County into the Dan River, lawmakers passed a law demanding the energy company end the use of coal ash ponds by 2030.

On April 1, the Department of Environment Quality ordered that Duke Energy excavate the remaining nine ash basins to make sure there are no future spills. The order specifically targetted the basins at Duke Energy’s Allen, Belews Creek, Cliffside/Rogers, Marshall, Mayo and Roxboro facilities.

Duke Energy issued a statement days later, arguing that excavation would put a financial strain on customers, suggesting the company would recoup the cost by increasing energy bills. The company announced that it intended to appeal.

The DEQ determined that excavation was the only option that met the requirements of the Coal Ash Management Act “to best protect public health,” specifically by disposing of the ash in a lined landfill.

The company described the DEQ’s order as “the most expensive and disruptive closure option possible,” adding that the department describes the basins in question as “low risk.”

This new plan, which would fall short of full excavation, reduces the cost for Duke Energy to close the basins. Closing the remaining basins will cost the power company $1.5 billion, bringing total costs to close the Carolina basins to about $8 billion to $9 billion.

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