Santee Cooper officials are nervously monitoring the Waccamaw River as it continues to rise, days after Hurricane Florence, toward a large stockpile of coal ash near Conway. Their goal: keep the ash out of the coastal river.
Coal ash contains metals that, in high doses, can be toxic to people and wildlife. The Waccamaw winds past the now-demolished Grainger Generating Station, where 200,000 tons of ash awaits excavation, and into the lush Waccamaw National Wildlife Refuge.
The Grainger site, where ash is being excavated for recycling into cement and concrete, had a near-miss with Hurricane Matthew in 2016. The Waccamaw peaked at a record flood stage of 17.9 feet, within 1 to 3 feet of the top of the dikes impounding the ash.
After Florence, the river is projected to set a new record, reaching 18.7 feet by Saturday but possibly rise higher next week.
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“We’d be within inches, probably,” of flooding the ash basin, Santee Cooper spokeswoman Mollie Gore said Monday. The river’s flood stage near Conway is 11 feet. It was at 15.4 feet Monday evening.
Coal ash is a legacy of Southeastern utilities’ decades-long reliance on coal to make electricity. It’s a fuel most utilities are phasing out in favor of natural gas, a cheaper and cleaner-burning alternative, and solar energy.
The millions of tons of ash that utilities were left with as they make that transition has haunted some. Duke Energy spilled 39,000 tons of ash into North Carolina and Virginia’s Dan River in 2014, leading to $102 million in federal fines and state orders to close its ash-disposal basins statewide. Most of the ash that turned the Dan River gray for 80 miles was never removed.
Flooding from Florence led to a possible ash release at Duke’s Sutton Lake near Wilmington over the weekend.
Santee Cooper, a state-owned electric and water utility, has worked since last week to safeguard the stored ash at Grainger, draping it with tarpaulins to keep rain out.
Twenty-two pumps are working to pump water from the river into the basin that holds most of the ash, to equalize pressure on the earthen dikes from inside and out. A thousand feet of inflatable rubber dams have been put in place to keep river water out. Sacks have been filled with 1.5 tons of rock each to be lifted by helicopter, if needed, and placed in breaches in the dike. Containment booms to catch floating particles arrived Sunday.
“We’re doing all this contingency planning, but we don’t know what will happen,” Gore said. “We’re trying to be situationally prepared.”
Myrtle Beach draws drinking water from the Intracoastal Waterway, which connects to the Waccamaw southwest of the city.
Santee Cooper agreed to excavate and remove the ash from its coal-fired power plants in a 2013 agreement with conservation groups represented by the Southern Environmental Law Center. That settlement became part of a state-approved plan to close its ash basins.
About 1.4 million tons of ash has been excavated from Grainger since 2014. Santee Cooper had agreed to remove all of it by 2023 but accelerated its work after Matthew, Gore said, and was on track to finish the job by the end of this year.
While the federal government doesn’t consider coal ash itself to be hazardous, ash contains potentially harmful metals, including lead, arsenic, selenium and mercury. Those contaminants pose a threat to aquatic life, said Coastal Carolina University scientist Susan Libes, director of the Conway university’s Waccamaw Watershed Academy and its Environmental Quality Lab.
It’s hard to assess the impact of Grainger’s ash, if it reaches the river, without knowing the concentrations of those metals, Libes said. But floodwater would dilute them.
“This is a relatively pristine river, but you have very rapid water flows right now,” she said. “It’s quite possible the solids and particles will get transported quite far downstream, toward Winyah Bay, before they can settle out.”
The bay is the third-largest estuary on the East Coast, a marine nursery where young fish and other animals grow. Water flowing down five rivers to the bay meets incoming tides there. Because of that water movement and the changing chemistry that happens when freshwater meets saltwater, Libes said, estuaries are efficient at trapping pollutants attached to solid particles.
It’s also helpful that estuaries are rich in biological activity, she added. Algae and other microbes can accumulate metals, then carry them to the bottom sediment when they die.
Jane Guentzel of Coastal Carolina’s marine science department said high levels of metals in ash can cause neurological, reproductive and development problems in fish, mussels, worms and amphibians. Because metals can accumulate in the tissue of those animals, she said by email, they also pose threats to the raccoons, birds and people who eat the smaller prey.
“We don’t want that stuff in our water,” said Waccamaw Riverkeeper Cara Schildtknecht.
Schildtknecht credits Santee Cooper for its efforts to keep ash out of the river. After the high water of Matthew, she said, “they saw it coming” when Florence swirled toward its territory.
The wildlife in the Waccamaw refuge downstream of Grainger are vulnerable to contaminants in ash, she said. So are the young fish and animals in Winyah Bay, which teems with life.
While the plants and animals in the bay are adapted to changing ratios of freshwater and saltwater, Schildtknecht said, “they’re still not adapted to carcinogens and neurotoxins.”