Safety of Duke’s SC coal ash ponds questioned

sfretwell@thestate.comFebruary 22, 2014 

— Water is seeping through a coal ash dam in the foothills of South Carolina, raising concerns about the structure’s stability and whether a failure would contaminate the Saluda River.

But the seepage at Duke Energy’s power plant in Anderson County has gone largely unnoticed as environmental groups and federal prosecutors focus much of their attention on the company’s troubles in North Carolina.

Duke, the energy giant with headquarters in Charlotte, finds itself in the middle of a criminal investigation in North Carolina and company officials are trying to explain why they couldn’t prevent a major coal ash spill into the Dan River near the Virginia border.

Since Duke has 14 coal ash sites in North Carolina, it makes sense the attention would not be focused on the two places in South Carolina that Duke owns.

Records show, however, that environmental concerns have turned up at both of the utility’s ash sites in South Carolina, most prominently along the Saluda River between Greenville and Anderson. The company’s other coal ash site is in Darlington County.

In 2010, consultants for the Environmental Protection Agency noted elevated water levels at one of the Anderson County coal pond dams and a history of seepage along the base of the other. Those issues could compromise the safety and stability of both structures, the report for the EPA said.

The report, prepared by GEI Consultants Inc., classified the ash pond dams as a “significant hazard” to the Saluda River because of the environmental impact they could have if a collapse occurred. A breach to the dams, which impound 64 acres of coal ash and wastewater, could send a large amount of ash into the Saluda, the report said.

GEI’s study didn’t find an imminent threat of failure from the coal pond walls, but it recommended monitoring seepage at the base of one dam. Evidence compiled during a site visit indicated seeps had been occurring for nearly a quarter century along what is known as the site’s “secondary ash pond” dam.

It wasn’t clear from the report whether the seeping water is coming from the coal ash ponds or is groundwater welling up into the dam. But excess water in an earthen dam can erode the structure and destabilize it.

“The main issue of potential concern for the (ash) impoundments identified in our field assessment was the flowing water and the soft wet soil” below one of the two ash dams, according to the December 2010 study. “Duke Energy personnel indicated that the seepage has been present for at least 24 years.”

Duke conceded last week that seepage still is occurring from the dam, but said that’s not abnormal and that the structure is safe. State regulators also said they believe both dams are stable, although they said the power company is making modifications.

“Some seepage through an earthen dam is common,” Duke spokesman Ryan Mosier said, but he emphasized that “seepage monitoring indicates no unusual conditions to date.”

Coal ash critics don’t see it that way.

In addition to concerns about the dams in the GEI report, the study questioned whether the foundation of the polluted ash ponds and dams could withstand an earthquake.

Previous studies, relying on a method of measuring soil stability known as a “blow count,” showed the earth beneath the Anderson County ponds and dams is relatively soft, said Steve Jaume, an earthquake specialist at the College of Charleston after The State newspaper made him aware of the study.

How dangerous are spills?

Spills from coal ash lagoons can be devastating to the environment.

A spill that occurred this month at a Duke site on the Dan River of North Carolina sent toxins into the water, threatening fish and aquatic organisms. Duke finally plugged a leaking pipe and announced plans to dredge the river after the water turned gray with ash. A second leak also has been stopped. Federal officials now are asking whether state regulators were diligent enough in monitoring the coal pond.

The worst spill in U.S. history occurred in Kingston, Tenn., about five years ago, when a coal dam broke and sent a wave of poisoned water into rivers. The deluge killed fish and drove people from their homes.

Coal ash is the residue of burning the fossil fuel to make electricity. It contains an array of toxins. Those often include arsenic, selenium and mercury, all poisons that can cause health problems or even death to people and animals who come in contact with the pollutants. Some aquatic animals regularly exposed to coal ash develop deformities.

In addition to questions about threats to the Saluda River in Anderson County, groundwater pollution is a concern.

Coal ash ponds operated by both SCE&G near Columbia and Santee Cooper near Myrtle Beach have poisoned groundwater with high levels of arsenic. Unlike Duke’s coal ponds, those are slated for cleanup.

At Duke’s sites, groundwater does not appear to have the same high levels of contaminants found at other places around the Carolinas. But it is not pollution-free, either.

Recent groundwater sampling at Duke’s Darlington County site detected an elevated level of toxic chromium in a monitoring well, according to the S.C. Department of Health and Environmental Control.

Chromium exceeded the maximum contaminant level for safe drinking water at the H.B. Robinson coal site just outside of Hartsville, DHEC said in response to questions from The State.

At the company’s W.S. Lee site in Anderson County, elevated levels of iron and manganese have shown up, DHEC said.

Peaceful river

Duke Energy’s Lee steam station, built in 1951, is nestled in a rural area of woodlands and farm fields about 2 miles east of Williamston, a small textile town 102 miles northwest of Columbia.

Just downhill from the company’s power plant and coal ponds is the Saluda River, a long waterway that extends from the Blue Ridge Mountains to the central Midlands in Columbia.

The source of drinking water for hundreds of thousands of people between Greenville and Columbia, the river also is popular with people who like the outdoors. Crappie and catfish fill the river and deer are abundant along its banks. Nongame species also can be found there, including birds that thrive in the tangled habitat.

Kenny Cooley loves the community and its peaceful nature. But he’s concerned about the coal ash ponds at Duke’s Lee steam station down the road from his house.

People used to fish in the ash ponds, but the whoppers they caught often carried a petroleum flavor that was hard to get used to, Cooley said last week as he stood in his front yard and looked through a thin veneer of trees at Duke’s ash basins. The company no longer allows access to the property, he said.

Worried about groundwater pollution, Cooley said he has tapped onto a public water system to avoid any threat to his family’s health.

“I said, ‘This might be sinking into our wells,’ so I moved” to public water, the 64-year-old barber said. “I’m always worried about carcinogens.”

Environmentalists, while conceding that they’ve been busy with Duke’s coal ash basins in North Carolina, said Duke Energy’s South Carolina ponds present their own hazards.

Although a breaking coal dam can devastate a river, an unlined waste pond can let toxins ooze into groundwater – and many are unlined, conservationists say.

“People should be very concerned,” said Donna Lisenby, a former South Carolina resident now involved in the regional fight over coal-fired power plants and contaminated ash basins that serve them.

Coal ponds in five states tested by the Waterkeeper Alliance are leaking, and “most of them aren’t safe,” Lisenby said. “The most worrisome thing is all the high-hazard dams.”

Frank Holleman, an environmental lawyer in Greenville and one of Duke’s chief agitators, suggested the possibility of a lawsuit to clean up the South Carolina sites. But he said DHEC should spearhead the cleanup effort since its job is to protect the environment in the Palmetto State.

“The problem is that for years on the Saluda River, the system has not operated properly. The dam has leaked,” Holleman said. “That’s a warning sign.’’

Duke says it is following the law and keeping the South Carolina ash ponds safe.

DHEC records show the agency has cited Duke a handful of times for water pollution violations at its Robinson facility near Hartsville in Darlington County and its Lee steam plant near Williamston. Those citations include a $7,267 fine in 2007 for discharging heated water that killed fish in the Saluda River.

Holleman said the best way for Duke to reduce environmental threats in South Carolina is by digging up all the coal ash it deposited in ponds and hauling it to a landfill. That’s especially important since the company has closed the Darlington coal site and is in the process of shuttering the one in Anderson County, where a gas-fired plant will be constructed in its place, he said.

Holleman’s organization, the Southern Environmental Law Center, successfully sued two other utilities in South Carolina, SCE&G and Santee Cooper, seeking an ash cleanup. Both companies have agreed to dig out their ash ponds during the next 10 to 15 years and dump the material in landfills or recycle the ash. The decisions have been held up as a model for Duke to follow.

Aside from a complete dam failure, Holleman said even a partial break could pollute the Saluda River because Duke has a pipe to the Saluda to catch pond wall seepage. The pipe could act as a “conveyance” for a rush of polluted water, similar to the pipe discharge on the Dan River, he said.

Safe operation

Duke Energy, which supplies power to much of North Carolina and to northern South Carolina, said there’s no reason for the public to be worried about ash dams anywhere – including on the Saluda River east of Williamston or on the flat plains of Darlington County.

The company is committed to safety, Mosier said.

In Anderson County, Duke has responded to questions in the EPA report and is convinced the ash pond dams are in good shape, Mosier said. The company routinely checks dams after heavy rains or earth tremors and has found no problems, he said.

“Analyses indicate the dams are stable in their current condition,” Mosier said in an email to The State. “Special inspections are conducted immediately after unusual conditions, such as significant rain and seismic events, to help detect areas that could be distressed and to facilitate immediate repair.”

The modification Duke is making to one of its Lee dams is for an outfall structure that carries some drainage water away from the embankments, records show. Erosion – and failures – are less likely if the dams are not saturated with water. Duke’s improvements to the dam involve trying to repair a pipe that carries away seepage.

Mosier said seepage water goes through a “toe drain” to the river. That protects the coal ash dam from saturation. The discharge has been approved by state regulators.

Despite calls by environmentalists to clean out the ash basins to reduce the threats, Duke says only that it is studying the future of the ponds near Williamston and Hartsville and it will come up with the most realistic plan for closing the basins.

The company’s position on the South Carolina ash ponds mirrors its stance on ash basins in North Carolina, where Duke has resisted efforts by environmentalists to dig out the ash to reduce threats to rivers.

“Closure planning studies are currently under way at many retired North Carolina plants with ash basins, and we plan to follow a similar process in South Carolina,’’ Mosier said.

“Our focus is developing closure plans that will protect the environment, neighbors and customers. Each site is different with respect to soils, hydrology and other aspects that inform our planning, so we will leave it to the science to tell us what closure approach will be the best fit for W.S. Lee and Robinson.”

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