Correction:  This version clarifies the fact that the Sutton coal ash pond was earlier designated as high risk.

The coal ash pond at Duke Energy's Sutton Energy plant in New Hanover County is one of four such ponds in North Carolina classified as high risk and must be excavated and closed by December 2019, according to a new report containing draft classifications from the N.C. Department of Environmental Quality (DEQ).

"Work at those four sites must be completed by August 2019. As such, we have been excavating coal ash at Sutton since late October 2015 and taking the ash to a fully lined structural fill at a former clay mine in Chatham County (Brickhaven Mine)," Duke Energy spokesman Jeff Brooks said in an email Friday.

Duke is still awaiting final designation of 10 of its coal ash sites, Brooks said.

The report, released Friday, contains the scientific data used to determine the risk level at each of Duke Energy’s 33 coal ash ponds within a framework developed by Gov. Pat McCrory. The data was used to assess the threat an individual coal ash pond poses using three major criteria: the pond’s impact on surface water; its impact on ground water; and the structural integrity of the coal ash storage structures, according to a news release accompanying the report.

“From this assessment, a coal site is designated as either high, intermediate or low risk. Coal ash ponds designated as high-risk must be excavated and closed by December 2019; intermediate-risk ponds must be excavated and closed by December 2024; and low-risk ponds must be closed by December 2029,” the release stated.

The proposed risk classification of the Sutton plant, as well as that of energy plants in Buncombe, Rockingham and Gaston counties, is “high.”

Starting in March, a public meeting will be held in each county where a coal ash facility is located for public comment and review. The meeting to elicit public input on the Sutton coal ash pond takes place on March 1 at Cape Fear Community College.

The public comment period will close on April 18. The information gathered from the public will help inform the department’s final classifications, according to the release.