Legal Blogs and Updates

Print PDF
U.S. Supreme Court Rules That the Clean Water Act May Regulate Pollution Traveling Through Groundwater
U.S. Supreme Court Rules That the Clean Water Act May Regulate Pollution Traveling Through Groundwater

On April 23, 2020, the United States Supreme Court issued a decision in the County of Maui, Hawaii v. Hawaii Wildlife Fund et al. matter, finding that the Clean Water Act may regulate pollution traveling through groundwater. The Court also found that the Ninth Circuit Court of Appeals applied an overly broad standard in requiring permits in Hawaii for wastewater wells that discharged contaminants through groundwater to the Pacific Ocean. The decision has implications for private as well as public entities whose activities may involve discharges that could have either a direct or indirect connection through groundwater or other media with the waters of the United States.

The Clean Water Act prohibits discharges of pollutants from a point source to navigable waters. This case addressed what constitutes a discharge of a pollutant to navigable waters, and therefore requires a permit under the Clean Water Act. The County of Maui treats wastewater and pumps it through four wells into groundwater before it eventually reaches the Pacific Ocean. Environmental groups filed a lawsuit against the County of Maui alleging that Maui’s actions constituted a “discharge” of a “pollutant” to “navigable waters,” without the appropriate permit from the Environmental Protection Agency, in violation of the Clean Water Act.

In a split decision, the Supreme Court held that “the statutory provisions at issue require a permit when there is a direct discharge from a point source into navigable waters or when there is the functional equivalent of a direct discharge.” The Court stated that many factors may be considered in determining whether an activity is the “functional equivalent of a direct discharge,” including the distance the pollutant travels and the time it takes to travel to reach navigable waters, as well as less significant albeit relevant factors, such as the nature of the material through which the pollutant travels and the extent to which the pollutant is diluted or chemically changed as it travels.

The Supreme Court clarified that while its decision will guide other courts, it does not present a bright line rule for discharges to groundwater, as the analysis in individual scenarios will necessarily remain fact-specific. As such, courts will need to provide additional guidance through their decisions in individual cases.


Back to Page