On September 24, 2018, the Sixth Circuit held that the Clean Water Act (CWA) does not apply to pollutants that travel through groundwater before entering navigable waters in Tennessee Clean Water Network, et al. v. Tennessee Valley Authority, Case No. 17-6155.

The defendant in this case, Tennessee Valley Authority (TVA), operates a coal-fired power plant that produces coal ash as a waste product. TVA disposes of the coal ash (which is mixed with water) in ponds adjacent to the Cumberland River. While some of this coal ash wastewater is permitted to be discharged through a pipe to the Cumberland River, some wastewater is alleged to leak through the coal ash ponds into groundwater, which then traveled to the Cumberland River. The TVA’s permit covered the direct discharge from the pipe to the Cumberland River; it did not cover the indirect discharge to the Cumberland River (i.e. the discharge from the ash ponds to groundwater, and then groundwater to the Cumberland River).

The district court found that because the groundwater was “hydrologically connected” to the Cumberland River, and TVA did not have a permit to discharge wastewater from its coal ash ponds, it violated the CWA. As a matter of law, the district court determined that discharging without a permit from a point source through hydrologically connected groundwater to navigable waters is a CWA violation when the hydrological connection is “direct, immediate, and can generally be traced.”

In the recent decision, the Sixth Circuit disagreed with the “hydrological connection theory” and reversed the district court decision, holding that the CWA only applies to discharges made directly to a navigable water. The court adopted reasoning from the companion case, Kentucky Waterways Alliance, v. Kentucky Utilities Co., Case. No. 18-5115, issued the same day, that the basis of the CWA’s regulatory power creates a requirement that discharges be directly into navigable waters. The CWA regulates “effluent limitations,” which are defined as restrictions on pollutants that may be “discharged from point sources into navigable waters.” The court reasoned that the use of the word “into” indicates directness and a point of entry and therefore the CWA can only apply when pollutants are added directly to navigable waters.

The two Sixth Circuit decisions create a circuit split, as the Fourth and Ninth Circuits have applied the hydrologically connected theory and determined that the fact that a pollutant traveled through groundwater before reaching a navigable water did not preclude CWA liability. The split among the Circuit Courts makes the groundwater hydrological connection theory ripe for Supreme Court review.