(North Carolina) — Millions of pounds of Duke Energy’s coal ash, a byproduct of power plants that can contaminate water, lies underground in the Charlotte region as regulators increase their scrutiny of the waste.
Nobody knows whether it poses a threat. North Carolina requires no permits, protective liners or checks of groundwater when ash is used to fill gullies or prepare roadbeds and building foundations. Duke deposited 2.7 million tons of ash for those uses between 1992 and 2003.
State inspectors discovered the two known N.C. contamination cases, at so-called structural fill sites in Robeson and Nash counties, virtually by accident. They noticed improper practices while driving by.
Duke’s Belews Creek power plant in Stokes County proves the value of monitoring ash deposits. Duke had to shut down an ash landfill at the plant in 2008 after repeatedly exceeding state groundwater safety standards.
Public attention, meanwhile, has focused on coal ash in a different form – the watery slurries stored in basins at power plants – since a disastrous spill by the Tennessee Valley Authority spill near Harriman, Tennessee, last December.
Coal ash contains metals that can be toxic in high concentrations, and Duke Energy has recently detected tainted groundwater near its basins.
In the aftermath of the TVA spill and amid concerns about contamination, the Environmental Protection Agency is now considering whether to regulate coal ash as hazardous waste. The agency, which has promoted the use of ash in projects such as highway construction, says it will release a proposed rule by the end of this year.
In anticipation of stiffer rules, Duke plans to spend $140 million in the Carolinas – and $365 million companywide – by 2013 to install caps and liners at its existing and new ash landfills at power plants, according to recent Securities and Exchange Commission filings.
A 2007 state law required that liners and leak-detection systems be installed at new landfills, like the one Duke is building at its Allen power plant on Lake Wylie. Duke’s four new N.C. landfills will also feature synthetic caps to keep out rain that could soak the ash and wash contaminants toward groundwater.
But those laws didn’t apply a decade ago, when Duke deposited 450,000 tons of ash to fill deep gullies at a Lake Wylie horse farm near the Allen plant.
Ash a ‘fabulous product’
“When all this coal ash news came out last year, my concerns were that we’re on a community well and I wondered whether it could be contaminated,” said nearby resident Beth Montgomery, who remembers the rumble of hundreds of dump trucks a day hauling ash to the site south of the Gaston County town of Belmont.
Because state rules don’t require monitoring of such sites, said field operations chief Mark Poindexter of the state Solid Waste Section, if contamination occurred, “We would not know that.”
The latest water-quality samples for the community well that serves Montgomery’s family showed no high levels of metals that could be traced to the ash. State water samples from that part of Lake Wylie show high levels of naturally occurring iron and slightly elevated levels of copper, which isn’t associated with coal ash.
Mark Baxa, a physician and surgeon who owns the 45 acres where the ash is buried, said state officials did weekly tests over the course of the engineered installation. Eighteen to 24 inches of soil capped the compacted ash, Duke says.
Baxa said he also researched what was in the ash and concluded it’s a “fabulous product.”
“If I were given the choice of swallowing a mouthful of dirt or a mouthful of ash, I’d take the ash,” he said.
N.C. rules say ash should be tested for toxicity before being used in construction, although some scientists say the state’s prescribed test is unsuitable for that purpose. Ash can’t be placed closer than 50 feet of streams, 100 feet of drinking water sources or 2 feet of the water table, the rules say.
“We certainly met all the requirements at the time,” said Duke spokesman Andy Thompson. “This construction practice was accepted at the time.”
Baxa, who hasn’t had his own well tested, considers contamination a moot point and ash disposal part of the tradeoff for electricity.
As for the 29 to 30 horses grazing above his ash, he added, “their manes and coats have never looked better.”
Trying to learn more
Duke says 90 percent of its ash was used for construction purposes such as road beds, parking lots and building foundations. But the company hasn’t sold it for those uses since 2003, when the ash helped build a leg of Charlotte’s Outerbelt.
Its ash is now used mostly to make concrete and cement products – the preferred use, scientists say.
“The power companies, in our experience, have been pretty responsible, they tend to use it locally or on their own sites,” said Ed Mussler, permitting branch head in the Solid Waste Section.
But such sites don’t have monitoring wells to detect contaminated groundwater, Mussler added, “and they don’t get inspected unless somebody complains.”
Duke learned this year that groundwater is contaminated near the ash ponds at all seven of its N.C. coal-fired plants. That information came from a voluntary-monitoring program U.S. utilities began in recent years as part of an agreement with the Bush administration.
Duke is working with state environmental officials to learn more, including whether the contamination has migrated off the plants’ boundaries. State officials, and Duke, say there’s no evidence the tainted groundwater poses a public health hazard.
Lisa Evans, an attorney who works on coal ash issues for the Oakland, Calif.-based public interest law firm Earthjustice, cautions that “it may take many years for ash to release harmful constituents.”
During the 1970s and 1980s, EPA documents say, selenium flowing from an ash basin at Duke’s Belews Creek power plant wiped out 16 of the 20 fish species in adjoining Belews Lake.
A research scientist with the industry-supported Electric Power Research Institute said contamination from ash can also occur if structural fill installations are not designed properly or are put in the wrong setting, such as too close to wells.
Most structural fill sites pose no cause for alarm, said EPRI researcher Ken Ladwig. Whether sites need to be watched, he added, depend on circumstances.
“If you’re talking about 1,000 cubic yards of ash in a small gully, then absolutely not, it would be a waste of time and money,” he said. “If you’re talking about 1 million cubic yards put in an area with shallow drinking water wells around it, it would be prudent.”
Coal ash is suspected of contaminating wells throughout the town of Pines, Ind., now a federal cleanup site. And four environmental groups said last week they will sue over contamination by an ash landfill of a creek that flows through a wildlife refuge in Prince George’s County, Md.
Avner Vengosh is among the Duke University scientists studying the effects of the TVA ash spill, in which they detected high levels of arsenic, mercury and radiation. The team hasn’t yet researched ash used in structural fill, he said, but past studies are clear.
“Theoretically what we know about ash is that if you put it in an environment that interacts with water, you definitely would generate a leachate that could contaminate water,” he said. “The only question is the magnitude.”
By: Bruce Henderson