18 May 2010 – The U.S. Environmental Protection Agency (EPA) Region 4 today has approved the Tennessee Valley Authority’s (TVA) selected cleanup plan for the next phase of coal ash removal at the TVA Kingston site in Roane County, Tenn. The cleanup plan, one of three alternatives proposed to the public earlier this year, requires TVA to permanently store on site all of the ash being removed from the Swan Pond Embayment, which includes land and bodies of water adjacent to the TVA coal ash disposal area. The embayment area will then be restored to conditions that protect human health and the environment. After careful review of all comments received between January and April, TVA, EPA and the Tennessee Department of Environment and Conservation (TDEC), agreed that the selected cleanup plan provides the best option to protect public health and the environment.
The cleanup plan approved by EPA in a signed Action Memorandum (AM) was chosen above the others because of its protectiveness, ease of implementation and cost effectiveness.
The cleanup plan includes:
Removal and On-Site Storage: The cleanup plan calls for the removal and consolidation of approximately 2.5 million cubic yards of ash from the embayment. All the ash will be consolidated on-site in the re-engineered TVA coal ash disposal area, and no material will be taken off-site–eliminating potential impacts associated with off-site disposal. The cleanup plan virtually eliminates the risks and costs associated with shipping ash over public roads or by rail. Keeping all the ash on site will minimize heavy truck traffic in the Roane County community, reduce wear and tear on area roads, and be less disruptive to local traffic and commerce. On-site disposal also addresses community concerns about proper disposal and management of ash in off-site landfills.
Building Protective Perimeter Dike: TVA will place dry ash atop an engineered base layer of sand, gravel and geo-fabric. The dry ash will be placed into the on-site disposal area slowly so that it does not slide. A new dike will be installed around the entire perimeter of the coal ash disposal area to keep the ash from entering the embayment in the future. This dike will go 60 to 70 feet below the ground to the shale bedrock, and will consist of overlapping soil-cement columns that are able to withstand a local 6.0 magnitude earthquake. The coal ash area will incorporate measures to divert drainage and control runoff.
Closing the Disposal Area: Once all the ash has been put in place, a two-foot clay cover and one foot of top soil will be put over it. Vegetation will then be planted to prevent erosion. Upon completion, the structure will be closely monitored, and regularly inspected to ensure public health and safety. Long-term groundwater monitoring will be conducted.
The height of the closed coal ash disposal area will be approximately 25 feet above the road surface, which is about 30 feet lower than the former dredge cell. The ash pond will be closed at the same time as the former dredge cell. Closing the areas simultaneously will eliminate the need for imported fill material to close the ash pond, which is expected to result in schedule efficiencies and cost savings.
Restoration: Following the removal of ash to native sediments, the embayment ecosystem will be restored to conditions that protect human health and the environment. This includes the restoration of a complex mosaic of forested, scrub-shrub and emergent wetland plant communities that will provide diverse habitats for fish, semi-aquatic amphibians and bird species.
Drinking water, river water and groundwater in the area are sampled on a routine basis, and current results indicate no exceedances of drinking water standards or surface water quality criteria. Continued ecological, groundwater and river sampling will be conducted indefinitely after the cleanup is complete to monitor environmental conditions surrounding the site.
Field work to prepare for the cleanup is expected to begin in late May as the time-critical work on the site concludes. This portion of the cleanup is estimated to take about four years to complete and will cost approximately $268.2 million, which includes an estimated $686,000 in annual maintenance costs for the first 30 years once the cleanup is complete. Ongoing five-year reviews will be conducted to ensure the integrity of the ash containment.
The Action Memorandum and associated materials are posted on the EPA’s Web page at: www.epakingstontva.com. They are also available for review at the TVA Outreach Center and Kingston Public Library in Kingston, Tenn., the Harriman Public Library in Harriman, Tenn., and at the EPA Region 4 office in Atlanta, Ga.
Public comments were sought on the Engineering Evaluation/Cost Analysis (EE/CA) Report and the alternatives described in it to restore the environment. TVA’s responses to all comments received can be found in the responsiveness summary, an appendix to the Action Memorandum. Public comments on the AM itself are being accepted through 18 June 2010, and should be submitted via email to kingstoncomm@tva.com or in writing to:
TVA
P.O. Box 40
Kingston, TN 37763-0400
The AM will be the subject of a public meeting on Thursday, May 20, at the Roane County High School, 540 Cumberland St., Kingston, Tenn., from 5:30-8:30 p.m. Representatives from EPA, TVA, TDEC and other agencies and groups will be available to provide information and answer questions about the Kingston site cleanup.
A separate EE/CA Report for the residual ash in the river system that remains once the time-critical dredging is complete will be prepared at a later date.
CONTACT
Davina Marraccini
+1 404 562 8293
marraccini.davina@epa.gov
