The Tennessee Valley Authority is taking public comment until June 15 on an environmental assessment that covers a plan to phase out wet storage of coal combustion products (CCPs), including bottom ash and scrubber gypsum, at the coal-fired Bull Run power plant in Tennessee.
Currently, bottom ash and gypsum are sluiced to wet disposal areas onsite. To enable the wet-to-dry conversion, TVA proposes to install a mechanical dewatering facility for bottom ash and gypsum at Bull Run. At Bull Run currently, TVA handles fly ash on a dry basis, and no changes to those fly ash handling and storage procedures are proposed. The proposed dewatering facility would:
- allow TVA to close wet CCP handling and disposal operations at Bull Run;
- provide a potential revenue source from the possible future sales of CCPs and reduce the demand for native raw materials through substitution of CCP materials; and
- foster TVA compliance with present and future regulatory requirements related to CCP production and management.
The Bull Run plant is located in Anderson County, Tenn., about 5 miles east of downtown Oak Ridge and 13 miles west of Knoxville. Most nearby lands are U.S. Department of Energy reservation properties for the Oak Ridge facilities, but there are residential and recreational land uses in the vicinity. The plant was built between 1962 and 1966. Commercial operation began in June 1967. Nameplate generating capacity for the single unit is 950 MW. Winter net-dependable capacity is about 881 MW.
CCP is residue that remains after pulverized coal is burned. At various stages of the coal combustion process, different types of CCPs are generated. CCP produced at Bull Run is composed of three main byproducts: bottom ash, gypsum and fly ash. CCPs are currently exempt from hazardous waste regulations under “the Bevill Amendment,” the draft EA noted. The U.S. Environmental Protection Agency is currently considering regulation of CCP facilities, such as those operating at Bull Run. Regulatory options being considered by EPA include: classifying CCP as special wastes subject to regulation under subtitle C of the Resource Conservation and Recovery Act (RCRA;) and regulating coal ash under subtitle D of RCRA, the section for non-hazardous wastes. Under both options, EPA is proposing to establish impoundment safety requirements to address structural integrity and to prevent catastrophic releases.
TVA is still being dogged by the regulatory and legal aftermath from the failure of an ash impoundment dam at its Kingston coal plant in Tennessee. In December 2008, one of the dredge cells at Kingston failed and approximately 5 million cubic yards of water and coal fly ash flowed out of the cell.
TVA is continuing cleanup and recovery efforts at Kingston in conjunction with federal and state agencies. TVA completed the removal of time-critical ash from the river during the third quarter of 2010, and removal of the remaining ash is considered to be non-time-critical. TVA estimates that the physical cleanup work (final removal) will be completed in the last quarter of calendar 2014. A final assessment, issuance of a completion report, and approval by the state of Tennessee and the EPA are expected to occur by the second quarter of calendar 2015, said TVA in its May 4 quarterly Form 10-Q filing at the SEC.
Because of the uncertainty at this time of the final costs to complete the work prescribed by the Kingston ash disposal plan, a range of reasonable estimates has been developed by cost category. The range of costs varies from $1.1bn to approximately $1.2bn, TVA said.