Solicitor General Urges US Supreme Court to Review Whether Clean Water Act Regulates Discharges to Groundwater

January 10, 2019

The solicitor general‘s support for a grant of certiorari increases the likelihood the Court will address whether the Clean Water Act is violated by releases of pollutants to groundwater that subsequently enter a “water of the United States,” a question that could significantly affect the scope of discharges regulated under the Clean Water Act.

In County of Maui v. Hawai’i Wildlife Fund et al., No. 18-260, the US Supreme Court is considering a petition for certiorari seeking review of a decision of the US Court of Appeals for the Ninth Circuit, which held that a violation of the Clean Water Act may occur when a pollutant is released from a point source to groundwater and ultimately migrates to a body of water covered by the Clean Water Act. The Supreme Court asked the solicitor general to file an amicus brief addressing whether the Court should grant certiorari. In the brief, the solicitor general argues that the Court should grant certiorari because the Ninth Circuit’s decision conflicts with a decision of the US Court of Appeals for the Sixth Circuit. If the Supreme Court grants review, its decision on the merits will have a significant impact on the scope of the Clean Water Act—limiting discharges potentially covered by the act if it overturns the Ninth Circuit or broadening discharges potentially covered by the act if it affirms. And such a decision also has potential implications for the Environmental Protection Agency’s (EPA’s) recent proposed rule on the scope of “waters of the United States,” and the litigation that rule is likely to engender.


The Clean Water Act

The Clean Water Act prohibits the “discharge of a pollutant” without a permit, which is defined as the “addition of any pollutant to navigable waters from any point source.” 33 USC § 1311(a). The statute defines “navigable waters” to include “waters of the United States, including the territorial seas.” Groundwater has been explicitly excluded from “waters of the United States” by regulation. But the complex ways that hydrological connections occur in the real world make this statutory scheme complicated and have left several significant areas of ambiguity. One such important open question is whether a “discharge of a pollutant” can occur when a pollutant released from a point source flows initially into groundwater and that groundwater then flows into a “water of the United States.”

The Ninth Circuit Decision

County of Maui involves a Clean Water Act citizen suit brought against the County of Maui related to releases from its wastewater treatment facility. The plaintiffs argued that the county had violated the Clean Water Act by injecting wastewater through wells into groundwater, some of which entered the Pacific Ocean through submarine seeps. The county operated those wells under a permit pursuant to the federal Safe Drinking Water Act, but it did not have a Clean Water Act permit that would authorize it to discharge pollutants into navigable waters.

The Ninth Circuit held that this flow of wastewater into the ocean violated the Clean Water Act even though the county initially discharged the wastewater into groundwater. In so holding, the Ninth Circuit rejected the county’s argument that “the point source itself must convey the pollutants directly into the navigable water.” The Ninth Circuit instead found that an indirect discharge into a navigable water from a point source was sufficient for liability to attach, reasoning that “from the time of the [Clean Water Act]’s enactment, lower courts have held that the discharge into intermittent channels of any pollutant that naturally washes downstream likely violates [the act], even if the pollutants discharged from a point source do not emit directly into covered waters, but pass through conveyances in between.”

In a separate petition also being considered by the Supreme Court, Kinder Morgan Energy Partners v. Upstate Forever, No. 18-268, the US Court of Appeals for the Fourth Circuit held that a discharge of gasoline from a leak in an underground pipeline that made its way through groundwater into navigable waterways also violated the Clean Water Act. Like the Ninth Circuit, the Fourth Circuit concluded that “a discharge of a pollutant under the Act need not be a discharge ‘directly’ to a navigable water from a point source.” It reasoned that when pollution from a point source “has migrated and is migrating through ground water to navigable waters,” that movement is an “indirect discharge” covered under the act as long as it is “sufficiently connected to navigable waters.”

The Solicitor General’s Brief

The solicitor general argued that the Supreme Court should grant certiorari, based on a circuit split between the decisions of the Ninth and Fourth Circuits and the Sixth Circuit. The solicitor general pointed to two recent Sixth Circuit cases, Kentucky Waterways Alliance v. Kentucky Utilities Co., 905 F.3d 925 (6th Cir. 2018), and Tennessee Clean Water Network v. Tennessee

Valley Authority, 905 F.3d 436 (6th Cir. 2018), which both held that releases of pollutants into groundwater did not violate the Clean Water Act even if they ultimately flowed into navigable waters. In Kentucky Waterways, the Sixth Circuit held that the operator of a coal-fired power plant had not violated the Clean Water Act by storing coal ash in ponds that may have flowed through groundwater into a nearby lake. The Sixth Circuit explicitly rejected the reasoning of the Ninth and Fourth Circuits, instead concluding that the Clean Water Act only applies where pollution is added directly to navigable waters “by virtue of a point-source conveyance” rather than through an intermediate step. The Sixth Circuit applied the same logic again in Tennessee Clean Water Network, finding that pollutants that flowed from a coal ash pond into groundwater and then into a river did not violate the Clean Water Act.

The solicitor general also rebutted various arguments raised in the respondents’ brief asserting that certiorari was not warranted. For example, the respondents had argued that review was unnecessary in part because a petition for rehearing was still pending in Tennessee Clean Water Network. The solicitor general countered that even if a petition for rehearing were granted in that case, a circuit split would still remain based on the Sixth Circuit’s earlier decision in Kentucky Waterways. The solicitor general also disagreed with the respondents’ argument that the split between the circuits was minimal because the coal ash ponds at issue in the Sixth Circuit cases “were not point sources to begin with.” The solicitor general argued that while the Sixth Circuit had indicated doubt about whether coal ash ponds were point sources in dicta, the holdings of those cases did not depend on that issue.


The solicitor general’s brief increases the likelihood that the Supreme Court will grant certiorari, particularly given that the Court asked for the solicitor general’s view on the issue. The solicitor general’s argument also lines up with arguments made in the briefs of several other amicus curiae, including a group of 18 states, a group of state and municipal water agencies, and a conservative public interest organization.

If the Supreme Court grants certiorari, its decision could significantly contract or expand the scope of discharges subject to regulation under the Clean Water Act. If the Supreme Court upholds the Ninth Circuit’s decision, it could require businesses and facilities discharging to groundwater without permits to obtain Clean Water Act permits, and would create a risk of litigation for those that continue to discharge pollutants into groundwater without Clean Water Act permits. In contrast, if the Supreme Court agrees with the Sixth Circuit, discharges into groundwater could occur without risk of liability under the Clean Water Act.

Certiorari on this issue is sought while the Trump administration also seeks to narrow the scope of the Clean Water Act through regulation. As discussed in a previous LawFlash, a proposed joint rule by EPA and the Army Corps of Engineers would significantly contract the scope of waters defined as “waters of the United States” under the Clean Water Act. Thus, the proposed rule and a decision by the Court in County of Maui could together shrink significantly the activities that the Clean Water Act regulates.

A Supreme Court decision in this case could also serve as a bellwether for a potential future decision by the Court on “waters of the United States.” The composition of the Court has changed since it last wrestled with the reach of the Clean Water Act in Rapanos v. United States, 547 U.S. 715 (2006). Indeed, the authors of the plurality opinion in Rapanos (Justice Scalia) and the concurrence (Justice Kennedy) are both no longer on the Court. Proponents of a narrower application of the Clean Water Act, including the petitioners in County of Maui, likely suspect that a majority of the current Supreme Court may be receptive to their arguments.


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