The Tennessee Valley Authority said June 28 that it is marking two significant milestones in the Kingston Recovery Project with the completion of ash excavation around the storage cell that failed in December 2008 and the placement of a liner over the failed cell.
“These are major steps toward our goal of restoring the area to a condition that is as good as or better than it was before the spill,” said Bob Deacy, TVA senior vice president of Generation Construction.
The failure of a wet ash containment dam at the coal-fired Kingston power plant in Tennessee allowed millions of gallons of polluted water to run downstream, fouling the watershed below. Among other things, that spill sharpened calls for the U.S. Environmental Protection Agency to crack down on coal ash disposal, which, other than a 2010 proposal that it has not made final, is something the agency has not yet done.
Workers have removed more than 3 million cubic yards of ash from the middle embayment and areas north of the cell using excavating equipment. The ash will be covered and permanently stored on site, surrounded by an earthquake-resistant, reinforced wall tied into bedrock up to 70 feet deep, which is one of the largest walls of its type ever constructed in the U.S. Work on that structure should be finished this fall.
Workers are placing a liner over the containment cell — a significant step in the process of closing it by late 2014, TVA noted. The first section of the liner is already in place on a segment of the cell.
“It really is a light at the end of the tunnel,” said Craig Zeller, project manager for the U.S. EPA at Kingston. “Now we can focus more on long-term monitoring and other aspects of the project.”
TVA has implemented a long-term monitoring plan to continue to assess the ecological health of the river system. Work also is under way on public recreation areas, which will include fishing piers, walking trails and green space around the former Lakeshore Drive area and the middle and north embayments.
Said TVA’s May 3 Form 10-Q financial report about Kingston: “In December 2008, one of the dredge cells at the Kingston Fossil Plant (‘Kingston’) failed, and approximately five million cubic yards of water and coal fly ash flowed out of the cell. TVA is continuing cleanup and recovery efforts in conjunction with federal and state agencies. TVA completed the removal of time-critical ash from the river during the third quarter of 2010, and removal of the remaining ash is considered to be non-time-critical. In November 2012, the Environmental Protection Agency (‘EPA’) and the Tennessee Department of Environment and Conservation (‘TDEC’) approved a plan to allow the Emory River’s natural processes to remediate the remaining ash in the river, and to conduct a long-term monitoring program. TVA estimates that the physical cleanup work (final removal) will be completed in the first quarter of 2015. A final assessment, issuance of a completion report, and approval by the State of Tennessee and the EPA are expected to occur by the third quarter of 2015.”
The Form 10-Q said that amounts spent since the Kingston spill event through March 31 of this year totaled $908m. The remaining estimated spill liability as of March 31 was $217m.