The Tennessee Valley Authority will seek engineering and construction proposals next month to convert to dry storage all of its wet-storage impoundments for combustion by-products. The project, which will take until 2020 to complete and could cost up to $2 billion, follows the 2008 failure of a coal-ash pond at the utility’s Kingston, Tenn., powerplant that spilled 5.4 million gallons of waste material over 300 acres and into the Emory River. Cleanup could cost $1.2 billion.

Photo: TVA

Tennessee ash spill pushes TVA to rethink waste storage at all powerplants.

Robert Deacy, TVA senior vice president for clean strategies and project development, says by-products now will be placed in dry piles to be capped and covered. TVA will first convert five “high hazard” impoundments at four sites, with high environmental or population risk in the event of failure, says John Kammeyer, vice president of coal combustion products, projects and engineering.

TVA also will close 18 ash and gypsum ponds and build dewatering systems at four gypsum ponds. Deacy says the program is “very aggressive,” but costs could rise if the U.S. Environmental Protection Agency changes regulations to designate coal-combustion by-products as a hazardous material. The agency now is reviewing the designation.