FILE - In a Wednesday, Feb. 5, 2014 file photo, Duke Energy engineers and contractors survey the site of a coal ash spill at the Dan River Power Plant in Eden, N.C., as state and federal environmental officials continued their investigations of the spill into the river. North Carolina regulators said Friday, March 21, 2014, that they have asked a judge to withdraw a proposed settlement that would have allowed Duke Energy to resolve environmental violations by paying a $99,000 fine with no requirement that the $50 billion company clean up its pollution. (AP Photo/Gerry Broome, File)