Tennessee Spill: The Dredge Report
This is the second in a series of investigative reports on the fallout from the Tennessee coal ash spill. Research support was provided by the Puffin Foundation Investigative Fund at The Nation Institute.
The Tennessee Valley Authority's efforts to clean tons of toxic coal ash are set to cause a "major toxic event" that could kill entire fish species and send a human health threat slinking up the food chain, according to scientists.
On December 22 the largest industrial spill in US history sent an earthen tsunami consisting of 5.4 million cubic yards of toxic coal ash sludge roiling out of a man-made lagoon and into the Emory River, which flows into the Clinch and Tennessee rivers. The ash clogged a section of the Emory River's navigation canal, forming an underwater "dam" that state and federal officials say could soon cause a flood of toxic backwater. On March 20, in a race to beat spring rains, the TVA--a federally owned utility company--began sucking out the toxic-sludge dam with huge hydraulic machines, putting it on land to dry out and be hauled away by trucks.
A handful of scientists are saying that the river-clearing operation will unleash a deadly pulse of selenium, an element found in coal ash that's good for humans in small doses but toxic to people, fish and wildlife at high levels. Water-treatment plants can filter selenium out of drinking water, but humans may still ingest harmful doses by eating contaminated fish and wildlife.
The EPA's hazard summary cites long-term studies showing that exposure to high levels of selenium in food and water have led to discoloration of the skin, loss of nails and hair, excessive tooth decay and discoloration, listlessness and lack of mental alertness. The agency also labels selenium sulfide, a selenium compound, a "probable human carcinogen." The EPA summary says hazard summary: "Acute human exposure to selenium compounds via the oral route has resulted in pulmonary edema and lesions of the lung; cardiovascular effects such as tachycardia; gastrointestinal effects including nausea, vomiting, diarrhea, and abdominal pain; effects on the liver; and neurological effects such as aches, irritability, chills and tremors. Selenium's impacts on animals can also be severe."
"This isn't just about fish and wildlife," said A. Dennis Lemly, a biologist who studied selenium for three decades while working at the US Forest Service. Federal scientists have documented at least a dozen cases where selenium has killed off fish and animal species, the largest selenium-related environmental disaster in US history being at Kesterson National Wildlife Refuge in California. "Fish were poisoned and there were massive deaths and deformities in waterfowl and other aquatic birds," Lemly recently wrote in a technical report. "This episode of contamination was extensively researched and documented by the US Fish and Wildlife Service and the US Geological Survey."
Problems of the Past?
As the dredging operation rolls toward its tenth week, a new scientific report by university scientists painted a picture of a river system that's already "loaded" with toxic levels of selenium. It also found that the unregulated, unlined structure that failed in December could have been the contamination source, quietly leaching selenium for decades. A study conducted at Appalachian State University (ASU) suggests that TVA's dredging operation will not only kick up large amounts of selenium-infused river sediment but will also bear down on a river that's already on a toxic edge. "Preliminary data suggest the selenium in the fish tissues may be the result of legacy selenium from decades of release of this metal from ash settling in ponds at the TVA Kingston plant," the study states. Tom Welborn, an EPA scientist, told The Nation that ASU tests and other studies indicate that the selenium contamination near the TVA's coal plant "appears to be a historic problem," meaning that the selenium contamination has been around for years.
The TVA says that the ASU study's claim is unfounded. In a written response to questions submitted by The Nation, TVA officials said that the authority, two state agencies and the Oak Ridge National Laboratory are analyzing fish tissue for selenium, and that information about selenium levels in Tennessee rivers is slim. "While the Appalachian State University researcher's contention that selenium could have leached from the failed pond over the years is interesting, there is no data to support that contention," the statement said. A spokesperson for the Tennessee Department of Environment and Conservation (TDEC) said that the state has viewed the data from ASU. According to a TDEC statement: "We respect their views on this subject, but there is no evidence that materials have historically 'leached' from the ash ponds at the Kingston facility." Department officials also told The Nation that the TDEC had studied fish samples, finding that levels of selenium in their tissue "did not exceed EPA's draft national selenium criterion based on fish tissue concentrations." Federal and state officials say they are monitoring the dredging operation closely and will stop if the operation is found to kick up high levels of selenium from the sediment into the water column.
Pressure to Dredge
Despite warnings that the dredging may trigger a major toxic event, the TVA, backed by federal and state officials, is following through with its plans. "There apparently has been horrendous pressure to dredge at any costs," said Bryce Payne, an independent environmental consultant who has been working on fly ash for more than fifteen years. "But the fish and similarly vulnerable biota in the Emory and Clinch River system simply will not be able to tolerate additional selenium."
Payne, who is considered by some to be the nation's top expert on coal ash issues, has led a behind-the-scenes effort--alongside some of the nation's top selenium scientists--to convince the TVA that the selenium problem is a loaded gun, that the authority's water-monitoring plan is faulty on scientific principle and that alternatives to dredging may well help avoid serious damage caused by selenium.
In two recent conference calls with dozens of officials and experts, Payne laid out one alternate plan to avoid floods, by digging a bypass channel around the ash dam. Payne proposes alternate ash removal approaches, including one that calls for adding lime, a relatively inert substance that causes the ash to solidify in place in the river, then removing the ash in solid form, essentially locking in selenium loads. The downside: the technique has been demonstrated only on a smaller pilot scale. On March 20, Paul Sloan, deputy commissioner at the Tennessee Department of Environment and Conservation, sent an e-mail to Payne and over a dozen people, including TVA and federal officials, who had been on one of the conference calls. "We believe the risks of selenium contamination are manageable with proper planning and attention, and that the risks of delaying ash removal outweigh the risk that might associate with selenium," Sloan wrote. He said that the EPA and TDEC will carefully monitor river water near the dredge operation for selenium contamination and added that the agencies plan to "follow up on fish testing samples."
Federal officials, for their part, stress that they will monitor the river water closely, and shut down the multimillion-dollar dredging operation if too much selenium is found. "If selenium or other constituents we are monitoring exceed regulatory limits, the dredging will be stopped so we can determine appropriate next steps," said Dana Tulis, deputy director of the EPA's Office of Emergency Management.