Court Adopts Indirect Discharge Theory to Expand CWA Liability for Discharges Reaching Groundwater

two(February 6, 2018) – A three judge panel of the US Court of Appeals for the Ninth Circuit issued a unanimous decision in Hawaii Wildlife Fund v. County of Maui on February 1, addressing to what extent a point source discharge that reaches groundwater, and eventually discharges to a Clean Water Act (CWA) jurisdictional water, triggers the requirement for a CWA Section 402 National Pollutant Discharge Elimination System (NPDES) permit.  The decision could have a significant impact on NACWA members nationwide.   

The appeal arose from a district court decision holding that migration of pollutants from properly permitted underground injection control (UIC) wells, operated by NACWA member agency, the County of Maui, through groundwater into hydrologically connected navigable waters, violates the CWA.  NACWA filed an amicus brief with the Ninth Circuit in March 2016 urging reversal of the lower court ruling.

Unfortunately, the Ninth Circuit upheld the district court decision and embraced an indirect discharge theory in holding that Maui County is liable under the CWA because (1) the County discharged pollutants from a point source (i.e., the wells), (2) 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 the navigable water, and (3) the pollutant levels reaching navigable water are more than de minimis.

The Court also found that the County was liable for violating the CWA even though the state and EPA had declined to issue the County an NPDES permit and it was properly operating under a Safe Drinking Water Act UIC permit.  The Court held that the County had “fair notice” that its activity violated the CWA.

The Ninth Circuit’s ruling raises fundamental CWA legal issues and may have far reaching implications including an expansion of the universe of sources subject to NPDES permit requirements.  If the County of Maui decides to continue the challenge to the full Ninth Circuit or the US Supreme Court for review, NACWA stands ready to file additional briefs providing the national perspective on the significant ramifications of this decision.

Additional details on the decision are available on NACWA’s Litigation Tracking page.  Members with questions can contact Amanda Waters, NACWA’s General Counsel.