Army Corps Considering Coal Ash To Fix Levees

(Business Week 7-14-2010) The Army Corps of Engineers wants to use ash cast off from coal-fired electrical generation to shore up dozens of miles of Mississippi River levees, drawing fire from environmentalists worried that heavy metals from the filler might make their way into the river.
The corps announced the plan last month, touting the injection of a slurry of water, coal ash and lime into 25 miles of slide-prone levees in 200-mile stretch of the river from Alton, Ill., near St. Louis to tiny Gale on southern Illinois' tip as the cheapest, longest-lasting fix among several options it weighed.
A public hearing on the matter, scheduled Thursday in St. Louis, is certain to elicit questions from environmentalists who consider the use of coal ash -- also known as fly ash -- a bad idea despite corps assurances that it has been used trouble-free on levees near Memphis for more than a decade.
"This is an emotional issue with some people," Alan Dooley, a spokesman for the Army Corps' St. Louis district, said Tuesday. "But we are looking for a more permanent way of fixing the levees. We're looking at public safety and best use of taxpayer dollars."
Various studies have suggested the ash -- a remnant of coal-fired power plants and long used in making roads and cement -- contains arsenic, selenium, mercury and other substances defined as hazardous, and may be closely linked to cancer.
The corps has said clay used to build the levees more than a half-century ago wasn't strong enough to last long-term, its significant shrinkage at low moisture levels allowing for the formation of cracks that fill with water from precipitation, weakening the embankment.
The proposed slurry involving fly ash would fill cracks and meld with substances in the clay, producing a cement-like, soil-fortifying material that locks in trace metals within the ash, Dooley said.
Dooley said other options considered by the corps included carving out the weakened soil in slide-prone levees and replacing it with firmer ground trucked in, or mixing the dug-out soil with firming lime, then reinserting and compacting it. Dooley said such efforts were more expensive and time-consuming than the ash-slurry plan, though cost projections of any of the options were not immediately available Tuesday.
Environmentalists worry that heavy metals from the coal ash might be too unstable, degrade in the water and leach its way into the river, then be swept downstream to the Gulf of Mexico.
"The whole thing is an absurd idea," said Kathy Andria, president of the American Bottom Conservancy and chairwoman of the Illinois Sierra Club's Floodplain Task Force.
Andria said engineers and a geologist she consulted panned the idea as a gambit that could further pollute a river system that supplies drinking water to many communities near the affected levees and provides recreation such as swimming, boating and fishing.
"With enough toxins there are (in the river), we don't need the federal government putting more in," she said.
Concerns about coal ash were revived in December 2008, when 5.4 million cubic yards of it breached an earthen dike and spilled into and around the Emory River from the Tennessee Valley Authority's Kingston plant near Knoxville. The TVA -- the nation's biggest public utility -- is in the midst of a projected $1.2 billion cleanup of the mess.
The Environmental Protection Agency in May first proposed federal regulation of coal ash, perhaps as a hazardous waste form. The plan would allow coal byproducts to be used in concrete, wallboard and other building materials.
An EPA statement said one option would have EPA enforce compliance with waste management and disposal regulations, and another would set performance guidelines to be "enforced primarily through citizen suits."
To view the original article please go to: