RALEIGH, N.C. (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 of the Dan River in toxic gray sludge.

The state Department of Environment and Natural Resources said Tuesday it plans to reopen Duke’s wastewater discharge permit and consider changes that would require 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.