The Tennessee Department of Environment and Conservation and Attorney General announced a settlement with the Tennessee Valley Authority (TVA) of a lawsuit against TVA and the management of coal combustion residuals at its coal-fired Gallatin plant.

The settlement requires TVA to remove approximately 12 million cubic yards of coal combustion residuals (CCR) from its active coal ash ponds at the Gallatin Fossil Plant, as well as remediate the area, in accordance with Tennessee law. Under the agreement, TVA may either place the excavated material in a lined, permitted landfill or recycle the material for beneficial reuse in concrete or other construction materials.

The settlement also requires TVA to complete a final environmental assessment report to identify the extent of soil, surface water and groundwater contamination at the facility.

TVA noted that the settlement was reached "amicably." It estimated that roughly 13 million cubic yards of CCR material is held in various impoundments at Gallatin. That includes about 2 million cubic yards of material at what TVA said is a non-registered site, which is the oldest ash impoundment at Gallatin. That site is subject to a separate order and may not be moved.

The Gallatin plant entered service in 1956. Credit: TVAThe Gallatin plant entered service in 1956. Credit: TVATVA said in a statement that the Gallatin site has "complex geology" and groundwater flows.

"Because of those conditions, and the fact that Gallatin already has an onsite lined landfill, TVA believes that a conservative approach — moving the CCR to that lined landfill onsite, with the possibility of beneficial use — is the best option at Gallatin."

TVA said that an onsite landfill eases concerns for traffic and impacts associated with trucking to a facility offsite. The approach also is expected to shorten the time frame and cost for removal.

State environmental officials filed the lawsuit in Davidson County Chancery Court in 2015, alleging violations of the Tennessee Solid Waste Disposal Act and the Tennessee Water Quality Control Act as a result of TVA’s coal ash disposal practices at the Gallatin plant.

In November 2014, the Tennessee Clean Water Network and the Tennessee Scenic Rivers Association sent a 60-day notice of violation letter to TVA, the federal EPA and the Tennessee Department of Environment and Conservation under a provision of the federal Clean Water Act, alleging multiple violations at the Gallatin plant related to its operations of the ash ponds at the site.

TVA will have to close units at its coal ash pond complex in Gallatin by removing coal combustion residuals and remediating the area consistent with the Tennessee Solid Waste Disposal Act. Under the agreement, TVA must develop a plan for the removal of the material and submit the plan to Tennessee environmental officials for approval.

TVA must submit its plan by no later than Sept. 30, 2020. TVA must also provide a copy of its proposed plan for removal to the Tennessee Clean Water Network and the Tennessee Scenic Rivers Association. The citizens groups will have 30 days to provide comments on the proposal and provide a copy of their comments to TVA.

TVA must complete removal of the ash pond complex within 20 years of the environmental regulator's final approval of the plan.

TVA began operation of the Gallatin plant in 1956. Coal combustion residuals generated at the plant have been sluiced and treated in a series of on-site, unlined settling and stilling ponds.