RALEIGH, North Carolina (AP) — North Carolina regulators say they may force Duke Energy to move a pair of leaky coal ash dumps, more than three weeks after a massive spill coated 70 miles (112 kilometers) of the Dan River in toxic gray sludge.

The state Department of Environment and Natural Resources said Tuesday it plans to review Duke's wastewater discharge permit and consider requiring the company to remove its remaining coal ash from the site at Eden near the Virginia line to a lined landfill away from the river.

It would mark the first time state regulators have moved to force Duke to move its toxic waste away from rivers or lakes.

The agency's statement makes no indication if similar permitting changes are under consideration for Duke's other 13 dumps in North Carolina.