Updated

The U.S. Environmental Agency expressed concern last year that a proposed deal between North Carolina regulators and Duke Energy to settle pollution violations at two of the company's coal ash dumps was too lenient.

The North Carolina Department of Environment and Natural Resources released more than 13,000 pages of public records in recent days as a response to media requests following the Feb. 2 coal ash spill at a Duke plant in Eden, which coated 70 miles of the Dan River in toxic gray sludge.

Among them was a Sept. 27 email from EPA questioning a proposed settlement over groundwater contamination at dumps near Charlotte and Asheville that would have required the $50 billion company to pay $99,000 with no requirement to clean up the pollution. State officials have scuttled that settlement after it was criticized by environmental groups.