CHARLOTTE -- Duke Energy announced plans, Thursday, to permanently close coal ash basins and safely store coal ash from its North Carolina power plants.

The Charlotte-based utility submitted detailed coal ash excavation plans to the North Carolina Department of Environment and Natural Resources for ash stored at the high-priority Asheville Steam Electric Plant, Dan River Steam Station in Eden, Riverbend Steam Station in Mount Holly, and L.V. Sutton Steam Electric Plant in Wilmington. The total combined amount of coal ash stored at the four sites is 17.5 million tons.

The plans, and all associated permits, must be approved by DENR before any excavation can begin. Under North Carolina's Coal Ash Management Act, all basins at the four sites must be closed by Aug. 1, 2019.