The Tennessee Valley Authority is soliciting public feedback on its initial plan to convert from wet to dry storage of coal ash byproducts at its Paradise fossil fuel power plant in Muhlenberg, Ky.
The utility's preferred alternative is to build and operate a new dewatering facility for coal ash byproducts, and a new dry fly ash conversion system and landfill, according to a draft environmental assessment released March 28. The option would involve a closure-in-place method and shutting down several ponds at the plant's site that store wet coal ash, including those currently used for sluiced gypsum, fly ash and boiler slag.
The new facilities proposed by TVA would be used by unit 3 at the Paradise plant. TVA plans to remove units 1 and 2 from service but leave unit 3 operational, with retrofitted air emission controls. The retiring units will be replaced with natural gas capacity currently under construction.
TVA said it also evaluated closure-by-removal for the impoundments, but the option was "eliminated from detailed consideration as it was determined to be unreasonable." The utility said the reasons for this include the size of the impoundments, excessive costs and increased environmental emissions that would result from closure-by-removal.
In 2009 TVA's board of directors committed to switching from wet to dry storage at its fossil plants including Paradise. The conversion will help the utility meet federal and state regulations, including rules set forth by the U.S. EPA regulating coal combustion residuals and providing limitations on wastewater from coal fired plants.
TVA said it will accept comments on the draft environmental assessment until April 27.
The utility's board in August 2016 approved its fiscal 2017 capital plan and budget, which allocated more than $2 billion for investments in cleaner energy sources, including the clean air equipment at Paradise and the construction of the natural gas combined cycle plant.
On TVA's first-quarter earnings call Jan. 31, president and CEO Bill Johnson said significant progress was being made on several projects, including the Paradise CC plant and the utility's other gas-fired project, the Thomas H Allen CC plant in Shelby County, Tenn.
On March 23, TVA released a draft EA on impacts of wet to dry storage conversion at its Gallatin fossil plant in Sumner County, Tenn. TVA found that building a dewatering facility with a recirculated bottom ash effluent stream is the only option that fully complies with the EPA limitations on wastewater. The facility would remove the water used in the coal ash management process, recycle it and then use it to move coal ash back into the powerhouse for continued use.