TVA Kingston Site Work Plan Released for Comment
The U.S. Environmental Protection Agency on Oct. 21 released the Tennessee Valley Authority’s (TVA) work plan with the proposed alternatives for restoration of the areas impacted by the coal ash spill at the TVA Kingston Fossil Plant in Kingston, Tenn.
The work plan addresses the remaining removal activities for the site that are not considered "time-critical" activities according to EPA. It is open for public comment through Nov. 20, 2009 at www.epakingstontva.com/. Comments should be submitted via email to kingstoncomm@tva.com or in writing to TVA, P.O. Box 40, Kingston, TN 37763-0400.
EPA and TVA signed an Administrative Order on May 11, providing the regulatory framework for all restoration efforts. The order requires TVA to submit for approval a draft Work Plan for performing one or more Engineering Evaluation/Cost Analyses (EE/CAs) for activities that are not time-critical. Current restoration efforts are being conducted as a time-critical removal action.
The EE/CA has two concurrent actions: address the Swan Pond Embayment and dredge cell area, and address the remaining ash in the Emory River (following the time-critical removal completion), as well as ash in the Clinch and Tennessee rivers. Significant data uncertainties exist in characterizing the river systems, and additional study and time are needed for comprehensive assessment of ecological risk in the rivers. After completion of additional data collection, alternatives will be developed that address any residual ash following completion of the time-critical removal action and any areas impacted by restoration activities.
The scope of the Swan Pond embayment/dredge cell removal action includes removal of the coal ash in the embayment, closure of the dredge cell, and disposal of the removed material. A range of alternatives for the embayment and dredge cell has been developed. Each of these alternatives involves removing ash and restoring the embayment to pre-spill conditions. The three alternatives are:
- Alternative 1 ─ Excavation of the embayment and off-site disposal. This alternative would remove the ash in the embayment and the ash from the test embankment within the dredge cell and dispose of the ash off-site. A dike would be installed to keep ash in the cell from entering the embayment in the future, and the dredge cell would be graded for drainage and closed. The height of the closed cell would be approximately 780 to 790 feet (ft) above mean sea level (msl). A total of approximately 2.7 million cubic yards (cy) of removed material would be disposed off-site.
- Alternative 2 ─ Excavation of the embayment and portions of the dredge cell, both with off-site disposal. This alternative would remove the ash in the embayment and test embankment, plus enough ash from the dredge cell to limit long-term reliance on a dike between the cell and the embayment. Enough ash would be left in the dredge cell to provide buttressing for the remaining dikes. The dredge cell would be graded to a gradual slope and closed, with a maximum height of approximately 765 to775 ft msl at its highest point. A total of approximately 6.3 million cy of removed material would be disposed off-site.
- Alternative 3 ─ Excavation of the embayment and on-site disposal in the dredge cell. This alternative would use the dredge cell as a disposal facility. No material would be taken off-site. The ash in the embayment would be removed and stacked in the dredge cell. Material placed in the cell for the test embankment would remain in the cell. A dike would be installed to keep ash in the cell from entering the embayment in the future, and the dredge cell would be graded for drainage and closed. The height of the closed cell would be approximately 790 to 800 ft msl.
The final decision on the type of removal action needed will be a balance of engineering effectiveness, implementation concerns, cost, regulatory requirements, and public comment. The removal alternatives will be described in more detail in an EE/CA report for the embayment and dredge cell, scheduled for late in 2009. This schedule will meet the objective of completing the decision in time to support field construction no later than the completion of the current time-critical removal actions, which is currently slated for completion in the spring of 2010.