Audit, Compliance and Risk Blog

Supreme Court provides greater clarity about when discharges to groundwater require Clean Water Act permits

Posted by Jon Elliott on Wed, Apr 29, 2020

contamination-4286704_1920On April 23, a six-member majority of the United States Supreme Court issued a decision that narrows the uncertainty about when a discharge of water pollutants to groundwater may require a Clean Water Act (CWA) permit (County of Maui v. Hawaii Wildlife Fund). The decision directly vacates the Ninth Circuit Court of Appeals decision it reviews, and effectively over-rules decisions by the Fourth and Sixth Circuits that differed with the Ninth Circuit but are also inconsistent with the Supreme Court’s new analysis. It also overturns guidance issued by the Environmental Protection Agency (EPA) in 2019 categorically excluding discharges from point sources to groundwater from regulation under the CWA National Pollutant Discharge Elimination System (NPDES) permit program; EPA's policy applied nationwide except in those three judicial circuits.

What were the facts of the case?

The County of Maui operates a sewage treatment plant, which produces 4 million gallons per day of partially treated wastewater which it discharges into four deep wells. The wastewater flows with/through groundwater approximately one-half mile to the Pacific Ocean.  In 2012 the Hawaii Wildlife Fund and other environmental groups sued the County, claiming that the discharge constitutes an unlawful “discharge” of a “pollutant” to “navigable waters,” since it occurs without a NPDES permit. The parties agreed that the wastewater would qualify as one containing “pollutants,” and that the ocean constitutes navigable waters of the U.S. (I wrote about recent changes to this definition HERE).

The case turned on the fact that the discharges are not made directly to the ocean but instead into groundwater, which flows to the ocean but does not reach it via a distinct channel or discharge point. The County argued that CWA applies only to direct discharges into navigable waters, and pointed to separate CWA provisions limiting EPA’s authority over groundwater to research and grant funding, and leaving groundwater management to states. The district court applied evidence to find that a considerable amount of the County’s wastewater reached the ocean and that a “path to the ocean is clearly ascertainable,” so that the discharge into wells was “functionally one into navigable water.”

The County appealed to the Ninth Circuit, which decided that a NPDES permit should be required when “the pollutants are fairly traceable from the point source to a navigable water such that the discharge is the functional equivalent of a discharge into navigable waters.” The County appealed to the Supreme Court, arguing a bright-line test: a discharge should only require a permit if it is the “means of delivering pollutants to navigable waters.” The federal government presented EPA’s latest guidance, seeking to exclude all discharges to groundwater as outside EPA/NPDES authority. The environmental groups incorporated the Ninth Circuit’s view, arguing that NPDES permits are required for discharges that are “fairly traceable” to a point source and a proximate cause of addition of pollutants to navigable waters.

What has the Supreme Court decided?

Justice Breyer wrote the majority opinion, joined by 5 other justices. Justice Kavanaugh wrote an additional concurring opinion highlighting several points, and Justice Thomas (joined by Justice Gorsuch) and Justice Alito dissented. The four opinions sparred over the CWA NPDES provision’s meaning of “from” in “discharge from a point source” to navigable waters.

The majority decided that limiting the term to mean only discharges directly from a source to navigable waters would create huge loopholes – pointing to a hypothetical where a discharger dumped its wastewater on a beach a few yards from the ocean – and adopted an admittedly vague definition covering “discharge from a point source into navigable waters or when there is the functional equivalent of a direct discharge.” This standard avoids loopholes such as the pipe-to-the-beach, leaving EPA and courts to decide whether particular discharges meet the standard. To assist these case-by-case analyses, Justice Breyer and the majority offered the following nonexclusive list of factors:

  1. transit time

  2. distance traveled

  3. the nature of the material through which the pollutant travels

  4. the extent to which the pollutant is diluted or chemically changed as it travels

  5. the amount of pollutant entering the navigable waters relative to the amount of the pollutant that leaves the point source

  6. the manner by or area in which the pollutant enters the navigable waters

  7. the degree to which the pollution (at that point) has maintained its specific identity.

The decision opined that time and distance will be the most important factors in most cases, but not necessarily every case.

Having reached this conclusion, the majority saw no reason to exclude ALL discharges to groundwater that might reach navigable waters, and pointed out that including such an exclusion would create loopholes comparable to the pipe-to-the-beach example.

Since the Ninth Circuit had applied a different analysis, the Supreme Court vacated the lower court decision and remanded the case for review applying this new analysis. The dissents argued that the majority had stretched the fair meaning of CWA’s statutory language, and lamented that the resulting standard lacks a bright line and therefore will lead to more litigation in more cases to come.

Now what?

This decision will set off nationwide reviews of discharges such as Maui County’s. The Ninth Circuit will review its prior decision, or further remand the case to the District Court to do so. It seems very likely that the lower court review will reinstate the requirement that Maui County seek a NPDES permit. Although not directly covered by this case, it’s clear that the Fourth Circuit view (requiring a “direct hydrological connection”) and the Sixth Circuit’s view (excluding all discharges to groundwater) are no longer viable. Neither is EPA’s recent exclusion of discharges to groundwater. 

Self-assessment Checklist

Does the organization routinely discharge wastewaters:

  • into groundwater

  • into waterways or possible conveyances that eventually drain to navigable waters of the United States

Are all such discharges already permitted by:

- EPA or a state agency applying delegated NPDES authority

- a state or local agency administering separate state authority

Are any non-permitted discharges subject to existing exemptions or waivers, which may be subject to review after this Supreme Court decision?

Where can I go for more information?


STP ComplianceEHS (STP) provides a variety of single-law and multi-law services, intended to facilitate clients’ understanding of and compliance with requirements. 

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About the Author

Jon Elliott is President of Touchstone Environmental and has been a major contributor to STP’s product range for over 30 years. 

Mr. Elliott has a diverse educational background. In addition to his Juris Doctor (University of California, Boalt Hall School of Law, 1981), he holds a Master of Public Policy (Goldman School of Public Policy [GSPP], UC Berkeley, 1980), and a Bachelor of Science in Mechanical Engineering (Princeton University, 1977).

Mr. Elliott is active in professional and community organizations. In addition, he is a past chairman of the Board of Directors of the GSPP Alumni Association, and past member of the Executive Committee of the State Bar of California's Environmental Law Section (including past chair of its Legislative Committee).

You may contact Mr. Elliott directly at:

Image by Yogendra Singh from Pixabay

Tags: Business & Legal, EPA, CWA, Hawaii Wildlife Fund, County of Maui, NPDES, Supreme Court, Groundwater discharge, water pollutants