Gallatin Coal Combustion Residual Facilities (Notes)	9 Months Ended
Jun. 30, 2019
Gallatin Coal Combustion Residuals Facilities [Abstract]
Gallatin coal combustion residual facilities [Text Block]	Gallatin Coal Combustion Residual Facilities Background TVA is involved in two lawsuits relating to alleged discharges of pollutants from the CCR facilities at Gallatin. Lawsuit Brought by TDEC. In January 2015, the Tennessee Department of Environment and Conservation ("TDEC") filed a lawsuit against TVA in the Chancery Court for Davidson County, Tennessee, alleging that pollutants from Gallatin have been discharged in violation of the Tennessee Water Quality Control Act and the Tennessee Solid Waste Disposal Act. The Tennessee Scenic Rivers Association ("TSRA") and Tennessee Clean Water Network ("TCWN") are also plaintiffs. On June 13, 2019, the parties filed a consent decree with the Court to resolve this matter, which the Court approved and entered on July 24, 2019. Under the consent decree, TVA agreed to close the existing wet ash disposal impoundments by removal, either to an onsite landfill or to an offsite facility, which will be determined after appropriate environmental reviews. TVA may also submit a plan that allows for beneficial reuse of the CCR material. Under the consent decree, TVA must submit a removal and closure plan to TDEC and must remove the CCR material within 20 years of TDEC’s approval of the plan. The consent decree does not contain penalties or any admission of fault or liability. In addition to the consent decree, TDEC entered an administrative order providing for ongoing investigation and monitoring related to a closed legacy impoundment at the site. After a five-year study period, TDEC and TVA will determine whether any additional corrective action and/or closure activities are necessary for the legacy impoundment. Lawsuit Brought by TSRA and TCWN. In April 2015, TSRA and TCWN filed a lawsuit against TVA in the U.S. District Court for the Middle District of Tennessee alleging that pollutants have been discharged into the Cumberland River from CCR facilities at Gallatin in violation of the Clean Water Act (“CWA”). The plaintiffs sought injunctive relief, including an order requiring TVA to relocate the CCR facilities, civil penalties of up to $37,500 per violation per day, and attorneys’ fees. On August 4, 2017, the court issued a decision (the "August 2017 Order") that found TVA had discharged pollutants into the Cumberland River in the past and that the discharge was likely ongoing. The court ordered TVA to excavate the CCR materials and move them to a lined facility. The court did not assess any monetary penalties against TVA for the CWA violations, citing the fact that its order to relocate the CCR materials would cause TVA to incur significant costs. On October 2, 2017, TVA appealed the August 2017 Order to the United States Court of Appeals for the Sixth Circuit ("Sixth Circuit"). On September 24, 2018, a panel of the Sixth Circuit reversed the district court decision and held that the district court erred by imposing CWA liability against TVA and that, therefore, the imposition of injunctive relief was an abuse of discretion. On October 22, 2018, the plaintiffs filed a petition requesting that the full Sixth Circuit rehear the case. On January 17, 2019, the Sixth Circuit denied the petition. On April 15, 2019, the plaintiffs requested review by the United States Supreme Court. Financial Impact Based on the August 2017 Order and the assumptions that a new lined facility would be permitted and constructed on the Gallatin site and all existing CCR materials at Gallatin would be moved to this site, TVA estimated the costs of the project to be approximately $900 million, which reflected the expected costs of inflation over the duration of the project but was not discounted to a present value amount given the nature of the obligation. At September 30, 2018, related liabilities of $862 million and $30 million were recorded in Other long-term liabilities and Accounts payable and accrued liabilities, respectively. As a result of the subsequent decision in TVA's favor by the Sixth Circuit, as well as the June 2019 consent decree filed in the case brought by TDEC, amounts previously recorded as Other long-term liabilities on an undiscounted basis have been reversed and an ARO in the amount of $667 million has been recorded for the discounted cash flows expected for the closure and post-closure activities related to Gallatin CCR facilities. See Note 11 for additional details. The ultimate cost of the removal project will depend on actual timing and results of ongoing litigation, environmental studies, licensing, permitting, site subsurface conditions, contractor availability, weather, equipment, available material resources, and other contingency factors. These contingency factors could cause the project cost estimate to change materially in the near term. TVA updates its estimate for project costs as changes in these factors are determined to be probable of occurring.

Gallatin Coal Combustion Residual Facilities

Background

TVA is involved in two lawsuits relating to alleged discharges of pollutants from the CCR facilities at Gallatin.

Lawsuit Brought by TDEC. In January 2015, the Tennessee Department of Environment and Conservation ("TDEC") filed a lawsuit against TVA in the Chancery Court for Davidson County, Tennessee, alleging that pollutants from Gallatin have been discharged in violation of the Tennessee Water Quality Control Act and the Tennessee Solid Waste Disposal Act. The Tennessee Scenic Rivers Association ("TSRA") and Tennessee Clean Water Network ("TCWN") are also plaintiffs. On June 13, 2019, the parties filed a consent decree with the Court to resolve this matter, which the Court approved and entered on July 24, 2019. Under the consent decree, TVA agreed to close the existing wet ash disposal impoundments by removal, either to an onsite landfill or to an offsite facility, which will be determined after appropriate environmental reviews. TVA may also submit a plan that allows for beneficial reuse of the CCR material. Under the consent decree, TVA must submit a removal and closure plan to TDEC and must remove the CCR material within 20 years of TDEC’s approval of the plan. The consent decree does not contain penalties or any admission of fault or liability. In addition to the consent decree, TDEC entered an administrative order providing for ongoing investigation and monitoring related to a closed legacy impoundment at the site. After a five-year study period, TDEC and TVA will determine whether any additional corrective action and/or closure activities are necessary for the legacy impoundment.

Lawsuit Brought by TSRA and TCWN. In April 2015, TSRA and TCWN filed a lawsuit against TVA in the U.S. District Court for the Middle District of Tennessee alleging that pollutants have been discharged into the Cumberland River from CCR facilities at Gallatin in violation of the Clean Water Act (“CWA”). The plaintiffs sought injunctive relief, including an order requiring TVA to relocate the CCR facilities, civil penalties of up to $37,500 per violation per day, and attorneys’ fees.

On August 4, 2017, the court issued a decision (the "August 2017 Order") that found TVA had discharged pollutants into the Cumberland River in the past and that the discharge was likely ongoing. The court ordered TVA to excavate the CCR materials and move them to a lined facility. The court did not assess any monetary penalties against TVA for the CWA violations, citing the fact that its order to relocate the CCR materials would cause TVA to incur significant costs.

On October 2, 2017, TVA appealed the August 2017 Order to the United States Court of Appeals for the Sixth Circuit ("Sixth Circuit"). On September 24, 2018, a panel of the Sixth Circuit reversed the district court decision and held that the district court erred by imposing CWA liability against TVA and that, therefore, the imposition of injunctive relief was an abuse of discretion. On October 22, 2018, the plaintiffs filed a petition requesting that the full Sixth Circuit rehear the case. On January 17, 2019, the Sixth Circuit denied the petition. On April 15, 2019, the plaintiffs requested review by the United States Supreme Court.

Financial Impact

Based on the August 2017 Order and the assumptions that a new lined facility would be permitted and constructed on the Gallatin site and all existing CCR materials at Gallatin would be moved to this site, TVA estimated the costs of the project to be approximately $900 million, which reflected the expected costs of inflation over the duration of the project but was not discounted to a present value amount given the nature of the obligation. At September 30, 2018, related liabilities of $862 million and $30 million were recorded in Other long-term liabilities and Accounts payable and accrued liabilities, respectively.

As a result of the subsequent decision in TVA's favor by the Sixth Circuit, as well as the June 2019 consent decree filed in the case brought by TDEC, amounts previously recorded as Other long-term liabilities on an undiscounted basis have been reversed and an ARO in the amount of $667 million has been recorded for the discounted cash flows expected for the closure and post-closure activities related to Gallatin CCR facilities. See Note 11 for additional details.

The ultimate cost of the removal project will depend on actual timing and results of ongoing litigation, environmental studies, licensing, permitting, site subsurface conditions, contractor availability, weather, equipment, available material resources, and other contingency factors. These contingency factors could cause the project cost estimate to change materially in the near term. TVA updates its estimate for project costs as changes in these factors are determined to be probable of occurring.