SUPPLEMENTARY INFORMATION:

This notice is provided in accordance with the Council on Environmental Quality's regulations and the TVA procedures for implementing the National Environmental Policy Act. On June 7, 2018, TVA published in the Federal Register (68 FR 53421) its ROD for the Cumberland Fossil Plant Coal Combustion Residuals Management Operations Final Environmental Impact Statement. The Final EIS identified Alternative C as TVA's preferred alternative, which includes the construction and operation of a Bottom Ash Dewatering Facility, closure-in-place of the Bottom Ash Impoundment, and a combination of closure-in-place and closure-by-removal of the Main Ash Impoundment and Stilling Impoundment. The portion of the Main Ash Impoundment and Stilling Impoundment that would be closed-by-removal would be repurposed as Process Water Basin 1 and Process Water Basin 2, respectively. The CCR that is removed from the impoundments would be transported to an existing onsite landfill (Fly Ash Stack). TVA elected to further consider options regarding the location for the permanent disposal of CCR excavated from these impoundments to support construction of the process water basins. In addition, TVA would construct an onsite landfill to manage future dry CCR produced at CUF.

TVA's CCR disposal areas at CUF, including the impoundments, are subject to the 2015 Commissioner's Order entered by the Tennessee Department of Environment and Conservation (TDEC). Investigations at CUF under that TDEC Order are ongoing. Therefore, TVA elected to further consider the proposed in-place closure of the Bottom Ash Impoundment and a portion of the Main Ash Impoundment before making a decision on closure of these facilities to allow the execution of the requirements of the TDEC Order to guide closure activities to the maximum extent possible.

As described in the Final EIS and subsequent ROD, TVA intends to construct and operate a new CCR landfill approximately 1.2 miles southwest of the plant site on CUF property. The approximately 80-acre landfill would have a total estimated capacity of 14.3 million cubic yards which provides adequate CCR storage for long-range planning purposes. TVA has decided to consider the future onsite CCR landfill for permanent storage of the CCR removed from a portion of the Main Ash Impoundment and Stilling Impoundment to support construction of the process water basins.

In addition, in consultation with the U.S. Army Corps of Engineers and TDEC, TVA has proposed a revised design of the future onsite CCR landfill that avoids direct impacts to surface water features associated with impoundments within the landfill boundary. This revised design includes the relocation of the proposed stormwater basin and the replacement of the proposed leachate impoundment with a leachate tank farm. However, the relocation of these facilities required additional area outside the boundary reviewed in the Final EIS. Additionally, ( printed page 55208) some areas along the eastern portion of the project area that were included in the original landfill boundary would no longer be needed to support development of the landfill. The revised landfill boundary encompasses a total of approximately 242 acres, compared to the original 174 acres, resulting in a net change of approximately 68 acres of additional disturbance.

In August 2019, TVA completed a supplemental review providing an analysis of potential impacts associated with the proposed change in the future onsite CCR landfill boundary and the use of this onsite landfill as a repository for both existing and future CCR rather than using the Fly Ash Stack (as originally proposed) as the storage facility for existing CCR. TVA now amends the June 2018 ROD ( Federal Register Vol. 83, No. 110) to incorporate the revised proposal. By this notice, TVA is providing notification of its decision and agency reasoning.

Environmental Consequences

In the Supplemental Analysis, TVA adopted the analysis in the 2018 Cumberland Fossil Plant Coal Combustion Residuals Management Operations Final EIS and provided supplemental analysis of the potential impacts with the proposed change in the future onsite CCR landfill boundary, in addition to using this new landfill as a repository for both existing and future CCR. The 2018 Final EIS identified that existing CCR would be placed in the Fly Ash Stack.

The proposed changes to the landfill location would increase the project's footprint by 68 acres. The proposed change would impact an additional 66 acres of low quality summer roosting and foraging habitat for threatened and endangered bats. An additional 2.0 acres of wetlands is within the revised project boundary. While additional water features were identified within the revised landfill boundary, the stormwater impoundment would be relocated and the leachate impoundment would be replaced by a tank system, therefore avoiding direct stream impacts. The remaining resources analyzed in the 2018 FEIS, including air quality, geology, groundwater, cultural and historic resources, public health and safety, parks and recreation, natural areas, visual resources, and socioeconomics and environmental justice, would see no additional impacts as a result of this increase.

Impacts to additional environmental resources would be slightly higher than those discussed in the 2018 Final EIS as well. However, the impacts would be minor and do not alter the overall impact findings and conclusions of the 2018 Final EIS.

Amended Decision

TVA has decided to amend the June 7, 2018 ROD to incorporate the proposed change in the future onsite CCR landfill boundary and the use of this onsite landfill as a repository for both existing and future CCR. The proposed action would result in additional impacts to resources than those reviewed in the 2018 Final EIS. However, the impacts would be minor and do not alter the overall impact finding and conclusions of the Final EIS.

Mitigation Measures

The June 7, 2018 ROD lists mitigation measures associated with the Cumberland Fossil Plant Coal Combustion Residuals Management Operations Final EIS to reduce adverse impacts associated with the proposed actions. These mitigation measures will remain in effect and are listed below. No new mitigation measures were identified during the supplemental analysis.

• A TDEC Aquatic Resources Alteration Permit and U.S. Army Corps of Engineers 404 permit will be required for disturbance to wetlands and stream features, and the terms and conditions of these permits would likely require mitigation for these proposed activities. TVA will adhere to all conditions stipulated in these permits.
• TVA will implement groundwater mitigation measures that could include monitoring, assessment, or corrective action programs as mandated by state and federal requirements. The CCR Rule and state requirements provide an additional layer of groundwater protection to minimize risk.
• TVA will coordinate with the Tennessee Department of Transportation and Stewart County transportation officials as needed to develop appropriate mitigation measures to reduce localized temporary transportation effects.
• Potential impacts to Wells Creek and/or Scott Branch from landfill leachate and stormwater discharges will be mitigated as required to meet permit requirements.
• Forested land within the proposed landfill project area is of low summer roosting quality for threatened and endangered bats, although it may be used as a foraging area. Section 7 consultation with U.S. Fish and Wildlife Service has been completed. No tree removal would occur between June 1 and July 31 to avoid any potential direct impact to juvenile bats at a time when they are unable to fly.
• TVA executed a memorandum of agreement with the Tennessee State Historic Preservation Officer to address the adverse effects of National Register of Historic Places listed site 40SW219.

Authority: 40 CFR 1505.2.

84 FR 55207