After coal ash spill in Tennessee, some see potential for trouble at Buck Steam Station
Published 12:00 am Wednesday, December 2, 2009
By Mark Wineka
Duke Energy’s Buck Steam Station has three coal ash ponds that are similar to the one that ruptured Dec. 22 in eastern Tennessee.
Are impoundments at Buck, which cover some 119 acres, a ticking time bomb of toxic waste?
Duke Energy says the company’s coal ash ponds systemwide have passed annual and five-year inspections and are in compliance with all existing laws and regulations.
“All ash basin inspections to date have been reviewed, and we are confident in those inspections,” says Tina Worley, a Duke Energy spokesperson. “Our review of records has not identified any dam citations.”
But environmentalists say the state and federal regulations are a joke and, in many states, non-existent.
Chandra Taylor, a staff attorney for the Southern Environmental Law Center in Chapel Hill, says household garbage in North Carolina is more regulated than the type of coal waste that spilled in Tennessee and is part of other wet storage impoundments like Buck’s.
“I think we should all be concerned about coal waste not stored in a way that’s protective of human health and the environment,” Taylor says.
The spill at the Kingston (Tenn.) Fossil Plant sent more than a billion gallons of possibly toxic sludge toward the Emory River and covered some 300 acres. On its path, it destroyed and/or damaged at least 45 homes and other properties.
Residents were evacuated, and local wells were put off limits out of fear of contamination from dangerous levels of arsenic and other heavy metals.
As with the Tennessee coal-fired power plant, the Buck Steam Station lies next to a major waterway ó in this case, the Yadkin River.
Duke Energy added Buck Steam Station’s “newest” pond in 1983. Of the three coal ash basins on the plant site, one is considered primary and the other two secondary, but all are in use.
The company says 5 million pounds of coal ash are stored in Buck’s three basins, which were constructed over a period of several decades. The steam station dates back to 1926 and is the oldest plant with coal-fired units in Duke’s system.
The primary basin collects the ash-water slurry and allows the ash to settle out. The second and third basins are used for additional water clarification.
Worley says a minimal amount of ash might pass from the primary to secondary basins, with “virtually very little ash” carried to the tertiary basin. The ash present in the secondary and tertiary basins was collected before construction of the primary basin, according to Duke Energy.
The ponds are contained by earthen dams, and their size or footprint at the site does not change.
A key focus when operating an ash basin is to ensure compliance with National Pollutant Discharge Elimination System permits, Worley says.
“In addition to meeting all water discharge requirements,” Worley says, “we have a basin inspection program to monitor the basins for minor leakage (seepage), settlement, erosion, vegetative growth and animal burrows.”
She adds that monitor readings to detect any instability also are reviewed.
The Buck coal ash ponds have no liners, but Worley says the existence of a liner would not have prevented the rupture that happened in Tennessee.
The Buck site does have monitoring wells, “and results are discussed with the state regulatory agency when enough data has been collected,” Worley says.
Duke operates 17 coal-fired stations in five states and has a total of 38 ash basins/ponds at those sites. Most of the ponds were constructed when the plants were built, though others were added when more capacity was required.
In North Carolina, Progress Energy and Duke Energy have coal ash ponds at 14 different locations, including Buck, which stores more coal ash than most plants, according to 2005 data.
The U.S. Energy Department statistics reveal that 156 coal-fired power plants store ash in hundreds of surface ponds over 32 states.
“Utilities have safely operated hundreds of coal ash impoundments for decades with only a few documented impoundment failures,” Worley says.
The coal ash ó sometimes called fly ash ó represents coal combustion waste. These contaminants once went through the smokestacks and into the air. The coal ash can be captured as solid waste and stored in huge piles or sent to dry landfills.
A cheaper alternative is to put it into the surface ponds.
Increasingly, coal ash is being sold for construction fill, mine reclamation and farm uses such as improving a soil’s ability to hold water.
Worley says Duke Energy manages its coal ash through a combination of programs, including its sale as a raw material to make cement. She estimates that 30 to 40 percent of the coal combustion byproducts are used “in beneficial ways.”
John Wear, director of the Catawba College Center for the Environment, says the ground floor of the center is concrete made with fly ash. The kind of coal a power plant such as Buck uses determines whether the coal ash has self-cementing properties and can be used in lieu of Portland Cement in construction projects, Wear says.
And that can have a real positive environmental result, Wear says, because there would be no additional carbon dioxide going into the air.
Wear says he has long been aware of the ponds on the Buck Steam Station site and recognizes how they could be of concern, especially with the string of Yadkin River reservoirs downstream.
Taylor, the staff attorney with the Southern Environmental Law Center, says the coal ash ponds raise fears of surface and groundwater contamination because heavy metals such as arsenic, lead and cadmium all exist in certain quantities that can cause risk to public health and the environment.
“We should also be concerned about how coal ash is reused,” Taylor says, adding if it’s not reused properly, the same risks exist.
She said it’s obvious that coal ash storage is growing. While it’s “very important and necessary to keep it out of the air,” Taylor says, it doesn’t excuse power companies from not disposing of the coal ash properly.
“There are ways to dispose of coal waste that are more protective (see accompanying story),” Taylor says. “They are more costly, but that’s part of the cost of burning coal for energy.
“There’s no such thing as clean coal, and it’s expensive to store it properly, but it has to be done.”
Power companies have successfully fought at least two previous efforts by the Environmental Protection Agency to classify coal ash as a hazardous waste. The industry has argued that it would cost billions of dollars a year to handle the coal ash under tighter controls.
In 2000, the EPA concluded that coal ash should be considered a non-hazardous waste with states as the primary regulators.
Regulations vary by state. Most states don’t require coal ash ponds to have liners or monitors that make sure hazardous metals aren’t leaching into aquifers. Basically, the ponds aren’t regulated at all, except through required water discharge permits.
Taylor says power companies should realize that the cost of a cleanup would be astronomical compared to taking steps to handle coal ash more prudently.
“It’s s shame something this terrible has to happen to bring attention to coal waste regulations,” Taylor says of the spill in Tennessee.