On August 4, the U.S. District Court for the Middle District of Tennessee issued a very significant ruling in the case of Tennessee Clean Water Network, et al., v. Tennessee Valley Authority. The District Court has ordered the Tennessee Valley Authority (TVA) to excavate huge quantities of coal ash waste generated over many years by the TVA’s coal-fired power plant located in Gallatin, Tennessee, and adjacent to the Cumberland River.

Two large unlined surface impoundments have been used to store this waste: the Non-Registered Site and the Ash Pond Complex. According to the District Court, these waste pits are located in an area with “karst geological features, with sinking streams, shallow bedrock, and sinkholes.” These site characteristics caused the District Court to note that “it is difficult to imagine why anyone would choose to build an unlined ash pond in karst terrain immediately adjacent to a river.”

The Tennessee Department of Environment & Conservation’s (TDEC)s National Pollutant Discharge Elimination System (NPDES) permit authorized the facility to discharge treated coal ash waste from only one location, Outfall 001, and it has been renewed without incident over the years. The plaintiffs’ Clean Water Act (CWA) Citizen Suit alleges that, regardless of the permit, TVA has unlawfully discharged pollutants into a navigable body of water (the Cumberland River) from specific point sources — the two surface impoundments — and these groundwater discharges are connected to the Cumberland River by means of a hydrological connection.

The District Court’s very long opinion (well over 100 pages) addresses a number of important issues in addition to the fundamental question of liability under the CWA: (1) the availability of a permit shield defense; (2) whether the TDEC’s prosecution of the TVA was diligent, requiring some deference by the court; and (3) the evaluation of conflicting expert testimony.

Regarding that fundamental question of the TVA’s liability under the CWA, the District Court framed the issue in these words: “a cause of action based on unauthorized point source discharge may be brought under the CWA based on discharges through groundwater if the hydrological connection between the source of the pollutants and navigable waters is direct, immediate, and can generally be traced.” Accordingly, the TVA has been ordered to excavate this waste and place it in “an appropriate lined site that does not pose a substantial risk of discharges into the waters of the United States.”

Although TVA has been ordered to remove this coal ash waste from these surface impoundments, the District Court declined to assess a civil penalty against the TVA, as the cost of this remedy would be penalty enough, especially as the District Court could not conclude that the violations of the CWA were “particularly severe.”