SCOTUS “County of Maui” Decision: More Clean Water Act Confusion

Updated: 6 days ago


On April 23, 2020, the Supreme Court issued a 6- 3 ruling in County of Maui v. Hawaii Wildlife Fund,handing down yet another confusing interpretation of the kinds of discharges requiring permits under the Clean Water Act (CWA). The Court held that discharges of pollutants to groundwater that are then conveyed to surface waters may be regulated if the discharges are the “functional equivalent” of discharges directly into surface waters.

Justice Breyer writing for the Majority laid out 7 non-exclusive factors that may be considered. However, it is highly uncertain, as to how these factors will be interpreted and applied.

The Maui decision stemmed from a long-standing dispute over whether discharges of pollutants from “point sources” such as pipes and wells that travel some distance and reach a stream or a river require CWA permits. The Maui County’s wastewater facility had pumped treated wastewater into the groundwater through injection wells which then reached the Pacific Ocean harming coral reefs and other aquatic resources.

The Ninth Circuit held that these discharges were regulated. The court held that pollutants found in the Pacific could be traced back to the injection wells. In reversing the Ninth Circuit and adopting the “functional equivalent” test, the Court offered seven “non-exclusive “ factors in evaluating whether such discharges need CWA permits;

(1) Transit time

(2) Distance traveled

(3) Nature of the material through which the pollutant travels

(4) Extent to which the pollutant is diluted, or chemical changed

(5) Amount of the pollutant entering the navigable waters relative to the amount of pollutant leaving the point source

(6) Manner by or area in which the pollutant enters the navigable waters

(7) Degree to which the pollutant (at that point) has maintained its specific identity

However, the Court readily admitted that the test may not be easily applied in individual cases and suggested that EPA guidance and future court decisions will likely be needed to clarify the kinds of discharges needing CWA permits.

The consequences

The universe of projects and activities impacted by the Maui decision is broad and covers municipal wastewater treatment, water transfer projects, residential and commercial development, mining, waste disposal and energy exploration and development to name just a few.

While further guidance is needed, here are few general observations:

  • Applying the Court’s factors could be extremely difficult and require technical experts that could delay or even prevent important projects. EPA and the Courts will have to use a practical commonsense approach in applying these factors for individual activities.

  • Projects requiring CWA section 404 permits for discharge of dredged or fill material will likely not be heavily impacted. Such discharges do not normally release pollutants into the groundwater that might travel to surface waters.

  • A vast percentage of discharges into the groundwater are regulated by the 46 states and the District of Columbia that have assumed the CWA section 402 NPDES program so the ruling may not change their permitting programs.

  • EPA and the States will have to develop streamlined permitting such as general permits for many activities that have minimal impacts in order to avoid a cumbersome and unworkable regulatory program.

Stay tuned for more developments.

Larry Liebesman, Esq.

Senior Advisor

A nationally recognized environmental lawyer with more than 40 years of experience, including 11 years at the U.S. Justice Department, Larry specializes in federal Clean Water and Endangered Species Acts and the National Environmental Policy Act (NEPA).


The views expressed here are those of the author and do not necessarily reflect the views of Dawson & Associates.

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