The Tennessee Valley Authority said June 15 that it is seeking public comment on potential environmental impacts of building a facility to remove and recirculate water used in the coal ash management process at Shawnee Fossil Plant located near Paducah, Ky.
TVA is proposing to build a dewatering facility for bottom ash at Shawnee as part of its commitment to convert from wet to dry storage of ash and other coal combustion residual products across the TVA system. The facility would include a recirculation system to recycle water used to move ash back into the powerhouse for continued use. The dry ash would then be stored onsite. The dewatering facility would also foster TVA’s compliance with current and future regulations related to coal combustion products.
TVA is inviting the public to comment on a draft Environmental Assessment which considers the potential environmental impacts of several alternatives, including construction of the dewatering facility. Comments will be considered as TVA prepares the final EA, which will be released later this year. Comments on the draft EA must be received no later than July 15.
The EA is being prepared to inform TVA decision-makers and the public about the environmental consequences of the proposed action. The decision TVA must make is whether to construct a dewatering facility or take no action.
Shawnee Fossil Plant is located on 1,696 acres along the Ohio River about 10 miles northwest of Paducah, Ky. It has nine active coal-fired units with a summer net capability of 1,206 MW and can generate about 8 billion kilowatt-hours of electricity per year. Shawnee consumes approximately 9,600 tons of coal a day which is 100% Powder River Basin (PRB) coal. CCRs, primarily ash, that are produced during power generation are managed on-site with “wet” impoundments and a “dry” landfill.
Under the proposed project, the bottom ash/water solution would be wet sluiced to a process dewatering facility that would eliminate the intermediate steps of settling in the impoundment and drying on the ground. The dry ash produced by the dewatering facility would be transported directly to the special waste landfill. However, water that would discharge from the dewatering process must be managed when it leaves the dewatering facility.
TVA’s plans for this water would be handled in two phases:
- In Phase 1, TVA would take excess water from the dewatering process and would route it into the existing wet trench and the existing bottom ash impoundment and stilling basin where it would be discharged according to TVA’s current permit requirements. This particular wastewater stream at would be discharged from a Kentucky Pollutant Discharge Elimination System (KPDES) permitted outfall (Outfall 001) into the condenser cooling water (CCW) channel, and would be ultimately released to the Ohio River through Outfall 002.
- In Phase 2, excess water from the dewatering process would be recirculated back into the intake side of the bottom ash sluice pumps at the powerhouse where it could be reused.