The Tennessee Valley Authority (TVA) is taking comment until Feb. 24 on a Draft Environmental Impact Statement (DEIS) that addresses the closure of coal combustion residual (CCR) impoundments at its coal-fired power plants.
CCRs are byproducts produced from the combustion of coal or the control of combustion emissions and include fly ash, bottom ash, and other materials. The purpose of this EIS is to address the potential impacts of closing CCR impoundments across the TVA system and to assist TVA in complying with the U.S. Environmental Protection Agency’s CCR Rule.
This draft EIS programmatically considers the impacts of the two primary closure methods:
- Closure-in-Place; and
The document is divided into two parts. Part 1 is a programmatic analysis that should generally be applicable to any CCR impoundment in the TVA system. Part 2 is an analysis of 10 site-specific ash impoundment closures and integrates the findings and conclusions of the programmatic document in Part 1.
In 2009, TVA outlined a plan to eliminate wet storage of CCRs at its plants and convert all wet fly ash, bottom ash, and gypsum operations to dry storage. This draft EIS evaluates those impoundment closure actions that are consistent with TVA’s overall plan to eliminate wet storage of CCRs at its facilities. Historically, TVA has managed storage of CCR materials in ash impoundments or dry landfills. After the dike failure and ash spill at the Kingston Fossil Plant in 2008, TVA’s Board of Directors directed TVA staff to review and address systems, controls, and standards related to CCRs. The outcome of that review was the plan to convert wet storage of CCRs to dry storage and close ash impoundments. This is being done on a project by project basis, subject to the technical feasibility, availability of resources and environmental review.
On April 17, 2015, the EPA established national criteria and schedules for the management and closure of CCR facilities (referred to as the CCR Rule). In the preamble to the CCR Rule, EPA asserted that if done properly either Closure-in-Place or Closure-by-Removal would be equally protective of human health and the environment. EPA observed that most facilities would be closed in place because of the difficulty of removing CCRs and costs. EPA purposefully structured its CCR Rule to encourage regulated entities to accelerate the closure of CCR impoundments because of the decrease in groundwater risk and increased structural stability that results from eliminating the downward hydraulic pressures of ponded water. These pressures are often referred to as “hydraulic head” which is defined as the force exerted by a column of liquid expressed by the height of the liquid above the point at which the pressure is measured.
TVA has coal-combustion power plants and ash impoundments in Alabama, Kentucky, and Tennessee. The ash impoundments within TVA’s system vary in size, and are represented by those that are less than 10 acres (ac) to those that are nearly 400 ac. Many of the existing ash impoundments are decades old, and the larger impoundments contain millions of cubic yards of CCR material. As part of this draft EIS, TVA is evaluating impacts of closing inactive and active impoundments as well as other impoundments that are not subject to the CCR Rule (e.g., plant is no longer generating power or CCR but still has storage basins that have not been closed to final grade).
TVA’s coal plants are:
- Allen Fossil Plant, Shelby County, Tennessee, three coal-fired units to retire once gas-fired combined-cycle facility at the site is active, two ash impoundments (one inactive and once active);
- Bull Run Fossil Plant, Clinton, Anderson County, Tennessee, plant is active, it has two ash impoundments (both inactive);
- Colbert Fossil Plant, Tuscumbia, Colbert County, Alabama, fossil plant expected to close in April 2016, has one coal ash impoundment (active);
- Cumberland Fossil Plant, Cumberland City, Houston County, Tennessee, plant is active, has two ash impoundments (both active);
- Gallatin Fossil Plant, Gallatin, Sumner County, Tennessee, plant is active, has four ash impoundments (all active);
- John Sevier Fossil Plant, Rogersville, Hawkins County, Tennessee, plant is inactive, one coal ash impoundment (active);
- Johnsonville Fossil Plant, New Johnsonville, Humphreys County, Tennessee, to be retired by Dec. 31, 2017, one ash impoundment (active);
- Kingston Fossil Plant, Harriman, Roane County, Tennessee, plant is active, two ash impoundments (both inactive);
- Paradise Fossil Plant, Drakesboro, Muhlenberg County, Kentucky, plant is active (plans are to retire two of three coal units later this decade), three ash impoundments (active);
- Shawnee Station Fossil Plant, Paducah, McCracken County, Kentucky, plant is active, one ash impoundment (active); and
- Widows Creek Fossil Plant, Stevenson, Jackson County, Alabama, plant to be retired by Oct. 15, 2015, three ash impoundments (inactive).
The draft EIS includes an integrated analysis of ten site-specific ash impoundment closures at each of six generating stations within TVA’s system of coal-combustion power plants. These coal-combustion power plants include Allen, Bull Run, Kingston and John Sevier in Tennessee, and Widows Creek and Colbert in Alabama.