On December 22, 2008, an ash disposal cell at the TVA Kingston Fossil Plant failed, causing the release of an estimated 5/4 million cubic yards of fly ash to the Emory and Clinch Rivers and surrounding areas. The release extended over approximately 300 acres outside the ash storage area. The failed cell was one of three cells at the facility used for settling the fly ash. The initial release of material created a wave of water and ash that destroyed three homes, disrupted electrical power, ruptured a natural gas line in a neighborhood located adjacent to the plant, covered a railway and roadways in the area, and necessitated the evacuation of a nearby neighborhood.
Shortly after learning of the release, EPA deployed an On-Scene Coordinator to the site of the TVA Kingston Fossil Plant coal ash release. EPA joined TVA, the Tennessee Department of Environment and Conservation (TDEC), the Roane County Emergency Management Agency, and the Tennessee Emergency Management Agency (TEMA) in a coordinated response. EPA provided oversight, as well as technical advice, for the environmental response portion of TVA’s activities. TVA conducted extensive environmental sampling and shared results with EPA personnel. EPA staff and contractors also conducted extensive independent sampling and monitoring to evaluate public health and environmental threats. In addition to providing information on environmental conditions at the site, EPA’s data also served as an independent verification of the validity of the TVA data.
EPA sampling included: surface waters of the Clinch and Emory Rivers, municipal water supply intakes, finished water (distributed from the water treatment plant) from potentially impacted public water systems, soils, private drinking wells, and coal ash. EPA also monitored airborne particulate levels in areas of ash deposition. The multimedia data were used to determine appropriate response measures that were protective of the environment and human health.
In the aftermath of the incident, EPA sampled the coal ash and residential soil to determine if the release posed an immediate threat to human heath. Sampling results for coal ash contaminated residential soil showed arsenic, cobalt, iron, and thallium levels above the residential Superfund soil screening values. Sampling results also showed average arsenic levels in the Kingston coal ash and coal ash contaminated residential soil above the EPA Region 4 Residential Removal Action Levels (RALS). RALs are used to trigger time-critical removal actions while soil screening values, are use as a point of departure from EPA to take any action to investigate and/or remediate a release. In response to exceedances of RALs for ash contaminated residential soils, TVA relocated residents to interrupt this soil exposure pathway. All other compounds in the ash and ash contaminated residential soil were below these soil screening values. EPA also analyzed the coal ash under the Toxicity Characteristic Leaching Procedure to determine whether the material would be classified as a hazardous waste. The analysis showed the material would not be classified as a hazardous waste. Since the failure, EPA, TDEC, and TVA have sampled multiple locations along the Clinch and Emory Rivers. Those sampling efforts detected heavy metals known to be contained in coal ash, but concentrations were below applicable limits.
The ash disposal cell which failed had been permitted by TDEC as a Class II Solid Waste Landfill under State regulations. TDEC served as the lead oversight agency for the clean up from January to May 2009. In January 2009 The commissioner of TDEC issued an order to TVA that among other things required TVA to submit a Corrective Action Plan for addressing the clean up of the ash spill. Additionally, in February 2009, EPA and TDEC sent a letter to TVA notifying TVA that, pursuant to Executive Order 12088, EPA considers the Kingston spill to be an unpermitted discharge of a pollutant under the Clean Water Act. In order to meet the requirements of both the TDEC Commissioner’s Order and Executive Order 12088, and to ensure the most efficient and expeditious collaboration between the three agencies, the letter directed TVA to provide copies of all plans, reports, work proposals and other submittals to EPA and TDEC simultaneously. EPA and TDEC have coordinated reviews and approvals of the submittals within their respective authorities. EPA’s overall objectives for the review and oversight are to ensure that the clean up protects public health, in full compliance with all applicable Federal law, proceeds in accordance with sound scientific principles, is done as quickly as possible, consistent with prudent management , and restores the ecosystem.