Duke says coal ash clean deadlines unrealistic

by Kate Elizabeth Queram, Wilmington Star-News, June 23, 2014.

Officials with Duke Energy said Monday that adhering to a proposed timeline for decommissioning coal ash basins across the state could be difficult, as closing procedures will vary widely from site to site.

The timeline, drafted by state legislators in a bill currently making its way to the Senate floor, would require each of the utility's 33 ash basins to be closed within five, 10 or 15 years, based on priority rankings. As written currently, the legislation calls for the Sutton plant in Wilmington along with Duke Energy's Dan River, Asheville and Riverbend sites to be cleaned up no later than 2019.

"Each of our sites is unique," Jeff Brooks, a spokesman for the utility, said during a media tour of the coal ash basins at the Sutton plant. "We have to understand the individual situation at that plant, and that allows us to have options as we discuss how to close down the ponds."

The tour, followed by an informational forum downtown for community members, took reporters through the facility's ash ponds – large, in-ground basins where utility companies store coal ash slurry, a mixture of water and fly ash, a lightweight byproduct of burning coal. The Wilmington ponds sit on the lip of Sutton Lake, just north of the old coal-fired plant.

That facility was decommissioned in November in favor of a new plant on the same grounds that burns cleaner natural gas. No coal ash has been added to the ponds since then, officials said.

When in use, the ponds functioned as a "multi-stage water treatment process," according to Brooks. Water was added to coal ash and pumped to the ponds via large orange and brown pipes that snake the perimeter of the property. The ash went first to an unlined basin, where it sat while larger particulate matter sank to the bottom. The slurry moved next to a "polishing pond," where finer particulate matter separated from water and fell to rest on the bottom of the clay-lined pit. The mixture moved finally to a "clear basin," a large, cattail-lined pond containing mostly water. After that, it discharges to Sutton Lake.

Traditionally, utility companies have just a handful of disposal options after ash ponds are decommissioned and dewatered. The ash can be removed and placed in lined, monitored landfills, or reused in some other manner, typically in concrete or cement. Ponds can also be capped and left in place, but the proposed legislation doesn't allow that option for sites – including Sutton – that have been deemed high or immediate risk.

Brooks said strategies would vary from plant to plant, and that some sites could use a mixture of options. But settling on a procedure for each facility within five to 15 years could be unrealistic, as Duke officials had originally estimated that statewide cleanup would take at least 30 years.

"These timelines are extremely aggressive," he said. "It will be difficult to achieve at some of our sites. Certainly we want to comply with the law, and we're asking for the time to do that."

Depending on the final plan, cleanup could cost anywhere from $2 billion to $10 billion. The legislation is expected to hit the Senate floor Tuesday.

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