The Tennessee Valley Authority said Sept. 15 that it is taking another step to change the way ash and other coal products are stored at the Shawnee Fossil Plant near Paducah, Ky.
TVA is proposing to build a dewatering facility to remove moisture from bottom ash created by the burning of coal at the plant. Bottom ash is particles of ash that are too large to be captured in the air and are instead collected at the bottom of the steam furnace. Water is currently used to move the ash into ponds for storage, but TVA is moving to a dry storage system at Shawnee and at all its fossil sites.
As part of the process, TVA has completed an assessment of potential environmental impacts for two types of dewatering facilities. Both would remove the moisture, but one would discharge the water from the facility to the river through a permitted location while the other would recycle the discharge water back into the powerhouse for continued use. In both cases, the dry products would then be stored at a special landfill onsite.
A Finding of No Significant Impact has been issued stating that neither option would have a significant impact on the environment. TVA also looked at the option not to construct a dewatering facility and continue to store the ash in on-site ponds. Two other options were removed for consideration for environmental and engineering reasons, and are described in the Environmental Assessment. TVA’s preferred alternative, and the one most likely to be built, is the facility which includes a recirculated discharge water system.
This project supports TVA’s plan to discontinue wet storage of coal combustion residuals, which helps comply with present and future regulatory requirements for coal combustion residuals (CCRs).
Shawnee is a 1,206-MW, coal-burning plant with nine generating units located on the Ohio River in McCracken County, Ky. The nine active coal-fired units have a summer net capability of 1,206 MW and can generate about 8 billion kilowatt-hours of electricity per year. The plant 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.