CHATTANOOGA, Tenn. — The Tennessee Valley Authority will permanently store onsite more than two million cubic yards of coal ash from a massive spill as part of the utility’s second phase of clean up.
At $270 million, the onsite storage will consist of 25-foot-tall heap with no liner system beside the Emory River west of Knoxville. It was the cheapest of several options TVA considered, and Steve McCracken, the utility’s cleanup project manager, said it should keep overall costs within the projected $1.2 billion total.
The onsite storage plan includes closing the ash pond that was contained behind an earthen dike until it failed at the coal-fired plant in Dec. 2008. The second phase is expected to take about four years and is to be followed by a third phase that includes monitoring the river for contaminants.
Environmental Protection Agency remedial project manager Craig Zeller said water and air monitoring in the spill area have shown no adverse health or environmental impacts.
“This has been a very carefully and comprehensively monitored cleanup project,” Zeller said.
While the spilled coal ash contained arsenic and potentially carcinogenic heavy metals, it is not regulated as hazardous waste. EPA recently decided to consider using some hazardous waste standards in regulating the ash.
TVA’s Dec. 22, 2008, spill sent 5.4 million cubic yards of ash into the river and onto nearby private property about 40 miles west of Knoxville in Roane County. In the first phase of cleanup that is near completion, the utility has dredged about 3 million cubic yards of ash from the river, much of it shipped by rail to a landfill in Alabama.
The TVA statement said dry ash will be stored onsite in Roane County on a “foundation of sand, gravel and geo fabric enclosed by an underground perimeter wall constructed of cement mixed with subsurface soil to divert drainage and control runoff.”
“The area will not include a liner system, however the long-term closure plan will include extensive groundwater monitoring of existing and new wells,” the statement said.
Brenda Timm, chairperson of the Roane County Community Advisory Group that opposed all of TVA’s proposed phase 2 options, said yesterday there is no other location “where the EPA would allow ash to be disposed of like TVA plans to do out there now,” without a liner system.
Zeller said “there is no discernible ground water contamination” at the site of the former ash pond.
He said the shipments of dredged ash to the lined Alabama landfill will continue until this fall. Phase 3 will involve removing another 500,000 cubic yards of “residual ash” from the river and environmental monitoring.
TVA also considered offsite disposal that would have involved trains and trucks — with cost estimates ranging up to $740 million — but McCracken said health and environment were also factors ahead of cost. He also said transporting the ash “does have risks” not posed by onsite storage.
“All those things get considered,” McCracken said.
Zeller said the closed area of the river is to be reopened May 29.
TVA is battling federal lawsuits seeking damages from the spill and has purchased more than 100 properties.
The utility has nearly nine million consumers in Tennessee, Alabama, Mississippi, Kentucky, Georgia, North Carolina and Virginia.