Gallatin Coal Combustion Residual Facilities (Notes)	6 Months Ended
Mar. 31, 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. TDEC seeks injunctive relief, which could include an order requiring TVA to relocate the CCR facilities, and civil penalties of up to $17,000 per day for each day TVA is found to have violated the statutes. The Tennessee Scenic Rivers Association ("TSRA") and Tennessee Clean Water Network ("TCWN") are also plaintiffs. Trial in this action is scheduled to begin in October 2019. 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 court's decision 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 February 1, 2019, the Sixth Circuit issued its mandate, which made its September 24, 2018, decision final. On April 15, 2019, the plaintiffs requested review by the United States Supreme Court. Financial Impact In August 2017, TVA began using regulatory accounting treatment to defer expected future costs of compliance with orders or settlements related to lawsuits involving the Gallatin CCR facilities. The TVA Board approved a plan to amortize these costs over the anticipated duration of the Gallatin CCR facilities project (excluding post-closure care), that began on October 1, 2018, as project costs are incurred. TVA has estimated these costs to be approximately $900 million. These costs include, among other things, environmental studies concerning the existing and new facilities, the permitting activities for the new facility, design and construction of the new facility onsite at Gallatin, relocating the material from the existing facilities to the new facility, closing the existing facilities, monitoring activities, and an amount of additional costs reflecting the expected impacts of inflation over the 24 year expected duration of the project. The costs do not include such items as any additional order or penalty arising from the TDEC lawsuit, which cannot be reasonably estimated at this time. TVA has not discounted this environmental obligation to a present value amount. TVA also plans on completing a capital project related to construction of a permanent bottom ash dewatering facility. This capital project, which is not included in the estimate for cleanup costs above, is estimated to cost approximately $71 million and be completed by 2020. It is reasonably possible that TVA will be required to move the CCR materials offsite, which would materially increase both the cost and the time to complete the project. TVA has estimated that if it is required to relocate the materials to a facility off the Gallatin site, TVA may incur up to $2.0 billion in expenses, plus an amount of additional costs reflecting the expected impacts of inflation given the extended duration of an offsite relocation project. It is estimated that the process of obtaining the necessary permits for offsite disposal, locating or constructing an offsite facility, and moving all of the CCR materials offsite would take approximately 40 years. 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. At March 31, 2019, related liabilities of $864 million and $22 million were recorded in Other long-term liabilities and Accounts payable and accrued liabilities, respectively.

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. TDEC seeks injunctive relief, which could include an order requiring TVA to relocate the CCR facilities, and civil penalties of up to $17,000 per day for each day TVA is found to have violated the statutes. The Tennessee Scenic Rivers Association ("TSRA") and Tennessee Clean Water Network ("TCWN") are also plaintiffs. Trial in this action is scheduled to begin in October 2019.

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 court's decision 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 February 1, 2019, the Sixth Circuit issued its mandate, which made its September 24, 2018, decision final. On April 15, 2019, the plaintiffs requested review by the United States Supreme Court.

Financial Impact

In August 2017, TVA began using regulatory accounting treatment to defer expected future costs of compliance with orders or settlements related to lawsuits involving the Gallatin CCR facilities. The TVA Board approved a plan to amortize these costs over the anticipated duration of the Gallatin CCR facilities project (excluding post-closure care), that began on October 1, 2018, as project costs are incurred. TVA has estimated these costs to be approximately $900 million. These costs include, among other things, environmental studies concerning the existing and new facilities, the permitting activities for the new facility, design and construction of the new facility onsite at Gallatin, relocating the material from the existing facilities to the new facility, closing the existing facilities, monitoring activities, and an amount of additional costs reflecting the expected impacts of inflation over the 24 year expected duration of the project. The costs do not include such items as any additional order or penalty arising from the TDEC lawsuit, which cannot be reasonably estimated at this time. TVA has not discounted this environmental obligation to a present value amount. TVA also plans on completing a capital project related to construction of a permanent bottom ash dewatering facility. This capital project, which is not included in the estimate for cleanup costs above, is estimated to cost approximately $71 million and be completed by 2020.

It is reasonably possible that TVA will be required to move the CCR materials offsite, which would materially increase both the cost and the time to complete the project. TVA has estimated that if it is required to relocate the materials to a facility off the Gallatin site, TVA may incur up to $2.0 billion in expenses, plus an amount of additional costs reflecting the expected impacts of inflation given the extended duration of an offsite relocation project. It is estimated that the process of obtaining the necessary permits for offsite disposal, locating or constructing an offsite facility, and moving all of the CCR materials offsite would take approximately 40 years.

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.

At March 31, 2019, related liabilities of $864 million and $22 million were recorded in Other long-term liabilities and Accounts payable and accrued liabilities, respectively.