Facilities that discharge wastewater with pollutants that have the potential to reach navigable waters via groundwater or other indirect pathways may see increased pressure in the year ahead from environmental organizations and regulatory agencies to obtain a federal Clean Water Act (CWA) NPDES permit for the discharge. Likewise, some facilities may proactively seek to obtain permitting to reduce the risk of potential citizen suits in light of the developing case law following the landmark U.S. Supreme Court decision in County of Maui, Hawaii v. Hawaii Wildlife Fund, 140 S. Ct. 1462 (2020). Together, these factors are likely to lead to an increase in the permitting of indirect discharges in 2022.

Last year, following remand in the County of Maui case, the U.S. District Court for the District of Hawaii ruled that the County was required to obtain an NPDES permit for the discharge of treated wastewater from the Lahaina Wastewater Reclamation Facility (LWRF) into groundwater via injection wells because the discharge of pollutants was the “functional equivalent” of a direct discharge to navigable waters. In granting summary judgment to the plaintiff environmental organizations, the Court analyzed the evidence against each of the functional-equivalent factors identified by the U.S. Supreme Court in its County of Maui decision as well as other factors.

The District Court ruled that the time and distance factors, said to be the most important, as well as the relative-amount-of-pollution-entering-the-water and the specific-identity factors weighed in favor of applying the NPDES permit requirement. It concluded that the undisputed evidence demonstrated that millions of gallons of wastewater are discharged annually into the Pacific Ocean, a navigable water, from groundwater seeps located approximately a half mile from the LWRF. The Court found no genuine issue of fact with respect to whether the discharge was the functional equivalent of a direct discharge to navigable waters. The County’s motion for reconsideration was denied by the District Court and the County does not intend to pursue further appeals.

The District Court’s analysis and application of the Supreme Court’s new functional equivalency test will likely be used in support of other claims advanced by environmental organizations that NPDES permits are required for indirect discharges elsewhere. Likewise, it may also serve as a key guide for permitting agencies.

Currently, there is no federal guidance on how to apply the Supreme Court test. Although EPA had published an initial guidance document in January 2021 under the Trump Administration, it was rescinded by EPA under the Biden Administration in September 2021. The recission memo noted that, consistent with past practice, and informed by the factors specified by the U.S. Supreme Court, EPA will apply site-specific, science-based evaluations to determine whether a discharge is the functional equivalent of a direct discharge.

Facilities with an existing discharge to groundwater or other pathway that may reach navigable waters, who do not currently have an NPDES permit, should consider evaluating available technical information concerning their discharge against these decisions and the functional-equivalent factors. This evaluation may assist in assessing the potential risk that a permit may now be required.