Effort to Assess Coal Combustion Residuals (CCR) Disposal Units
In 2008, one of the surface impoundments at the Tennessee Valley Authority’s (TVA) Kingston Fossil Fuel Plant failed causing CCR (also known as coal ash) and water to spill into the Emory and Clinch Rivers, flooding 300 acres of land, and forcing a nearby neighborhood to evacuate. In the wake of this disaster, EPA began a multi-year effort to assess the structural integrity of the surface impoundments and similar units managing residuals from the combustion of coal at the Nation's power plants.
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The first step EPA took was to request detailed information from each facility about the design, construction and operation of their coal ash impoundments. In response to this request, 676 surface impoundments and similar management units were identified at 240 facilities across the nation. For example, EPA obtained information on:
- the types of materials managed in the surface impoundment,
- whether the management unit was designed by a Professional Engineer,
- when the company last assessed the structural integrity of the unit,
- inspections or evaluations by regulatory officials, and
- known spills or unpermitted releases from the unit within the last ten years.
Next, EPA in collaboration with the U.S. States, undertook a comprehensive effort to assess the structural integrity of surface impoundments that contain CCR. The purpose of the assessments was to determine:
- whether the units were structurally stable, or
- whether any corrective measures were needed, and if so, to work with each facility to secure its commitment to complete any necessary corrective measures.
The assessments included a visual inspection of the site, interviews with site personnel, and the review of geotechnical reports and studies, if available.
EPA posted copies of the reports online and provided copies to each facility. EPA requested facilities implement the recommendations in the reports and provide plans for taking action including setting up a routine program to assess these units and taking necessary corrective measures.