The sludge lagoon failure at the Tennessee Valley Authority (TVA) Kingston Fossil Plant raises serious questions about the future of “clean coal.”
On the morning of December 22, 2008, an earthen dam on a 40-acre sludge lagoon broke releasing 5.4 million cubic yards of wet sludge, covering about 300 acres of land, destroying 3 homes, and breaking a major gas pipeline near Harriman, TN. The environmental cost will take a long time to assess.
What is this sludge? Coal doesn’t burn completely. It is an organic sedimentary deposit derived from ancient forested swamps containing, among other things, giant ferns the size of modern trees. After burning, the coal leaves a mineral residue called flyash that is collected from the power plant’s furnace. The flyash is the texture of silt, which is finer than sand but coarser than clay - about like flour.
Flyash can be used to make cement, concrete, asphalt, grouting materials, and other useful products, according to the Federal Highway Administration’s Turner-Fairbank Highway Research Center.
The market for flyash doesn’t keep up with it’s production, apparently, so the stuff piles up, either in wet lagoons or in dry piles. When the wet sludge enters water bodies, it’s constituent metals like arsenic, mercury, and lead pollute the water. The silt is suspended in the water column or coats the benthic community, causing problems for fish, fresh water clams, and other aquatic life.
When the siliceous dry sludge is wind-blown, it’s an air pollutant. Fine silica dust is a respiratory irritant responsible for silicosis.
According to the Engineering News Record, the lagoon has recently shown signs of trouble:
…Jack Sparado, a former national mine safety and health engineer, says that the inspection report indicates serious problems that TVA should have addressed. He conducted the engineering analysis of a similar, 300-million-gal, coal slurry spill in Martin County, Ky., in 2000 and wrote the engineering report of the Buffalo Creek, W.Va., coal slurry spill that killed more than 100 people in 1972.
Sparado says the dike has been failing since 2003 because of foundation piping, or internal erosion. There had been two minor blowouts in recent years and TVA noted seepage. The agency took corrective measures, Sparado says, but the only solution would have been to drain the reservoir and reconstruct the dam. “It was completely irresponsible of TVA to allow the dam to continue to be used when they knew of these previous problems,” he says. “They should have done a complete stability analysis of whole dam and essentially reconstructed it. It certainly should have been engineered better than it was.”
Ronald Hall, Kingston plant manager, says that other than the blowouts, TVA had “no indication or concerns leading up to the event.”
If Ronald Hall actually said that, he should be fired -at minimum. That’s just crazy.
The Knoxville News Sentinel is keeping an updated list of articles from various sources about the Kingston lagoon disaster and freelance photojournalist Antrim Caskey has this interesting set of photos:
Aerial view of the breach site at the Kingston Fossil Plant in Harriman, Tennessee.
Man with reptile.
Aerial view of the Kingston Fossil Coal Plant on December 29, 2008.
James Schean’s home thrown off its foundation
Set of all 17 photos.
The Natural Resources Defense Council’s blog OnEarth has a good summary of the incident, including an aerial video clip shot from a helicopter.
As America simultaneously rebuilds it’s economy and plans for it’s energy future, King Coal will fight hard to hold it’s current dominant position. Those of us who want clean renewable energy should gird their loins for a tough fight.