Utilities manage coal ash ponds threatened by Hurricane Florence

In the wake of Hurricane Florence, utility companies have worked to maintain the safe operation of coal ash basins and to keep coal ash in retaining ponds and out of rising rivers.

Charlotte, N.C.-based Duke Energy has closely monitored its 625-megawatt Sutton Power Plant, which used to be coal-fired until switching to natural gas in 2013.

On Sept. 15, Duke said that rain from Florence had caused a release of stormwater, which may have come into contact with coal ash from Sutton’s lined landfill. Through a statement, Duke said that about 2,000 cubic yards of soil and ash, enough material to fill about two-thirds of an Olympic-sized swimming pool, eroded from the landfill. According to Duke, “the majority of displaced ash was collected in a perimeter ditch and haul road that surrounds the landfill and is on plant property.”

Duke recently responded to concerns about contaminated water moving downstream by testing for environmental impacts. Duke spokesperson Dawn Santoianni said, “Water samples collected from various locations demonstrate that coal ash released from a landfill under construction has not impacted water quality in Sutton Lake in Wilmington, N.C.”

Duke also said on Sept. 20 that flooding has caused the Cape Fear River to flow across three normally dry, forested and inactive ash basins at the retired H.F. Lee power plant site in Goldsboro. Visual inspections with an environmental regulator showed that some cenospheres were released during the flooding. Cenospheres are lightweight, hollow beads comprised primarily of alumina and silica that are a byproduct of coal combustion, Duke explained.

“It also appears that only a small amount of coal ash has been displaced, similar to the impact in the wake of Hurricane Matthew. Crews will continue to monitor the situation,” Duke said in a written statement.

Dominion Energy, the other large investor-owned utility company with operations in the hurricane’s potential path was missed by most of the horrendous weather and addressed concerns by saying, “In Virginia, we have 11 coal ash ponds at four stations – Bremo, Chesapeake, Chesterfield and Possum. Most of the ash has been removed from five ponds and we’re in the process of removing ash from a sixth pond. Prior to and following Florence, we haven’t had any issues.”

Containing, transporting and ultimately safely disposing of coal ash remains a priority for the utilities. Hurricane season pulls the issue onto the front pages as public concern rises with the incoming tides. But prepping for a direct hit starts way before evacuations.

“We were very aggressive in preparing our ash basins for this historic weather event. We have been actively working on closing ash basins for some time, and water levels in many ash basins near the coast were lower as a result of our closure activity,” Santoinni said.

The utilities are focused on complying with changing regulations while keeping the lights on in extreme storms and making sure sensitive materials don’t spill in a flood.

It’s well documented that coal ash contains traces of heavy elements and other contaminants, but how much isn’t clear.

“There is an awful lot of misinformation when talking about coal ash,” Santoianni said. “Less than 1 percent of coal ash contains trace elements. We routinely test ash basin water, and that repeatedly shows the absence of toxicity.”

As more coal plants are retired, the problem of what to do with ash will become smaller each year.