The Environmental Protection Agency has approved a plan by TVA to leave more than 500,000 cubic yards of spilled coal ash at the bottom of the Emory and Clinch Rivers in Roane County.
In December 2008 more than a billion gallons of sludge was unleashed from the TVA Kinston Fossil Plant when a retaining pond failed. A large portion of that ash went into the Emory River and Clinch River beside the plant. After a year and a half of dredging the ash out of the water, crews stopped in the summer of 2010 and intentionally left a layer of ash at the river bottom.
"There were concerns about legacy radioactive material from pollution that originated decades ago from the Department of Energy in Oak Ridge in the form of Cesium 137," said Craig Zeller, EPA project manager at the Kingston ash spill. "The landfill that we were sending ash we removed during the dredging days was not interested in taking material that was potentially co-mingled with Cesium 137."
The legacy materials from Oak Ridge's nuclear operations are now buried under a layer of natural river sediment. When TVA devised three plans for how to deal with the remaining coal ash, it included a plan to let nature once again run its course and bury the past.
"The first option was to let natural sediment cover the ash and monitor the water quality for 30 years. That plan would cost around $10 million, with all of that being the cost of monitoring the water for 30 years," said Zeller. "There was a second option to cover the ash with a few inches of gravel that would cost $50 million. The other option was to keep dredging the rest of the ash and that could cost $80 million to $180 million."
Wednesday the EPA announced it had reviewed all three options in conjunction with state environmental officials at TDEC and approved the plan to let sediment naturally cover the ash.
"The other options were a lot more expensive and would not exponentially speed up the process of eliminating exposure to ash in the river. You might have to spend $180 million to get it all out in five years or you can let the river cover it naturally in ten years. Within ten years we expect the concentrations to go back to what they were prior to the spill."
Roane County executive Ron Woody said he agrees with the decision to let the river naturally take care of the remaining ash.
"I think it is the least invasive option. Let's let nature now heal what damage may exist," said Woody. "If in fact they find out there's some other issues out there, at any point in time they can go in at that time and dredge or do whatever they need to do."
Zeller said an exhaustive two-year $40 million collaboration to study any possible health hazards from the ash deemed the material very low-risk.
"This study examined a wide range of species and wildlife. A couple of bugs that live in the sediment showed some effects, but they also continued to flourish. Things like turtles, frogs, raccoons, the aquatic vegetation, and everything else checked out okay. Oak Ridge Associated Universities also did an extensive study on any health impact on humans and did not find any major risks. The river is open for recreation right now with the ash in the river."
In a press release, TVA says the process is known as Monitored Natural Recovery, and calls it the preferred option among several alternatives proposed to manage an estimated 500,000 cubic yards of remaining ash dispersed intermittently over more than 200 acres in the river system. TVA's selection of Monitored Natural Recovery, also called EE/CA Alternative 1, is documented in an Action Memorandum released by the agency.
TVA hosts a public meeting Thursday, November 8, at 5:30 p.m. at Roane County High School in Kingston to provide information and answer questions about the decision-making process and ongoing clean up.