Skip to main content
January 10, 2019

The Trump Administration Weighs In on Circuit Split on Discharges to Groundwater


Since its passage in 1972, courts have agreed that the Clean Water Act (CWA) does not cover discharges into isolated groundwater. However, both the Fourth and Ninth Circuits have rendered decisions this year holding that the CWA applies when a pollutant is discharged into groundwater and the pollutant migrates through the groundwater to a water of the United States. These holdings represent a major departure from the traditional jurisdiction of the CWA. The Trump Administration has weighed in on this increasingly complicated legal question by submitting an amicus brief asking the Supreme Court to hear this issue. Brief for the United States as Amicus Curiae, Cty. of Maui v. Hawaii Wildlife Fund, No 18-260, Kinder Morgan Energy Partners, L.P. v. Upstate Forever, No. 18-268. If the Court grants either petition, it will have a significant nationwide impact on the administration of the CWA.

The CWA prohibits the "discharge of any pollutant" into waters of the United States without a National Pollutant Discharge Elimination System (NPDES) permit (or, in the case of dredged or fill material, a Section 404 permit). The CWA defines the "discharge of any pollutant" as the addition of any pollutant to navigable waters, also known as "waters of the United States," from a point source. And the CWA defines a "point source" as "any discernible, confined and discrete conveyance" which includes pipes, ditches, channels, and wells. Until recently, it seemed settled that discharges into groundwater were not regulated by the CWA but instead by state programs. In fact, the CWA's legislative history shows that Congress considered whether or not to extend CWA jurisdiction to discharges into groundwater and declined to do so.

While the Fourth and Ninth Circuits have articulated standards by which groundwater may act as a conduit from a point source to navigable waters, thus triggering CWA jurisdiction, other Circuits have declined to do so. The Sixth Circuit, in two decisions, held in September that the CWA's definition of "discharge" requires that a point source deliver pollutants directly to navigable waters. The Sixth Circuit joins the Second, Fifth and Seventh Circuits in espousing this position. See United States v. Plaza Health Labs., 3 F.3d 643, 646 (2d Cir. 1993) (holding that point sources are "physical structures and instrumentalities that systematically act as a means of conveying pollutants from an industrial source to navigable waterways" and therefore discharges into groundwater did not trigger CWA jurisdiction); Rice v. Harken Expl. Co., 250 F.3d 264, 271 (5th Cir. 2001) (holding that any effort to construe the CWA to cover pollutants that reach navigable waters by "gradual, natural seepage" through groundwater would be an "unwarranted expansion of the [statute]"); Vill. of Oconomowoc Lake v. Dayton Hudson Corp., 24 F.3d 962, 965 (7th Cir. 1994) (holding that the CWA does not encompass pollutants seeping into "local ground waters" that may be hydrologically connected with surface waters).

Though not completely in agreement with one another, both the Fourth and Ninth Circuits have endorsed a version of the "conduit theory." The "conduit theory" places discharges through groundwater that is hydrologically connected to surface waters under CWA jurisdiction. In County of Maui v. Hawaii Wildlife Fund, the County operated a wastewater treatment facility that used underground injection wells to dispose of treated sewage, and pollutants from the well migrated to the Pacific Ocean through groundwater. 886 F.3d 737 (9th Cir. 2018). The Ninth Circuit held that the CWA covered this discharge because the original discharge was "from a point source" and "the pollutants are fairly traceable from the point source to a navigable water." Similarly, in Kinder Morgan Energy Partners LP v. Upstate Forever, a pipeline in South Carolina ruptured leaking gasoline into groundwater which later contaminated local streams. 887 F.3d 637 (4th Cir. 2018). The Fourth Circuit held that the "direct hydrological connection between groundwater and navigable waters" meant the discharge was regulated by the CWA.

However, in February 2018, soon after the Ninth Circuit issued its decision, the EPA published a Federal Fegister notice soliciting input on whether the agency should continue to adhere to these views. EPA solicited comments from interested stakeholders regarding whether and to what extent "subjecting such releases to CWA permitting is consistent with the text, structure, and purpose of the CWA." Clean Water Act Coverage of "Discharges of Pollutants" via a Direct Hydrologic Connection to Surface Water, 83 Fed. Reg. 7126, 7128 (Fed. 20, 2018). In seeking comment, the EPA intended to facilitate possible agency action in order to "provide additional certainty for the public and the regulated community." Id.

In response to the Supreme Court's request for the views of the Solicitor General on the pending petitions for certiorari, the Trump Administration on January 3, 2019 submitted an amicus brief in support of certiorari. The Solicitor General encouraged the Supreme Court to decide the following question: "Whether a 'discharge of a pollutant,' 33 U.S.C. 1362(12), occurs when a pollutant is released from a point source, travels through groundwater, and ultimately migrates to navigable waters."

While the Trump Administration did not choose a side in its response to the Supreme Court, it nonetheless declared a strong interest in the Court's resolution of the issue: "Given the potential breadth of those provisions, and the ways in which groundwater may be connected to navigable waters," the case "has the potential to affect federal, state, and tribal regulatory efforts in innumerable circumstances nationwide." Brief for the United States, supra note 1, at 13-14. The brief also noted the serious implications for regulated parties as "CWA violators may face serious civil penalties and, in certain cases, criminal punishment." Id.

The ramifications of this issue are indeed sweeping. Previous cases grappling with the issue of discharges into groundwater have covered a wide array of industries and factual circumstances, from wastewater treatment to oil pipelines to coal ash management.

We will keep you posted on whether the Supreme Court agrees to hear this matter and the results of EPA's reevaluation.

© Arnold & Porter Kaye Scholer LLP. 2019 All Rights Reserved. This Advisory is intended to be a general summary of the law and does not constitute legal advice. You should consult with counsel to determine applicable legal requirements in a specific fact situation.