EPA issues guidance on Supreme Court’s Maui decision for NPDES permitting program

By Jim Bradbury and Courtney Cox Smith
James D. Bradbury, PLLC Attorneys

The Environmental Protection Agency (EPA) on Jan. 14 issued a guidance memorandum regarding the recent Supreme Court decision in County of Maui v. Hawaii Wildlife Fund, 140 S. Ct. 1462 (2020). The Maui decision set out seven non-exclusive factors to consider when evaluating whether a discharge of a pollutant from a point source that travels through groundwater to a water of the United States (WOTUS) is the “functional equivalent” of a direct discharge.

In its guidance, EPA addressed the “functional equivalent” analysis within the context of the existing NPDES permitting program. These seven factors include: 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, and 7) the degree to which the pollution has maintained its specific identity.

The Maui decision specifically contemplated a case-by-case analysis that would be informed and further refined through lower courts, regulatory guidance and administrative proceedings. The EPA guidance memorandum is one of the first efforts to address the “functional equivalent” analysis and refine how it will work through the NPDES permitting program.

EPA emphasized that neither the Clean Water Act nor the functional equivalent test require an owner or operator of a facility to prove the absence of a discharge. Additionally, the Maui decision did not alter the threshold requirements for NPDES permits – namely that there be a discharge from a point source. EPA further highlighted that science dictates the extent to which a pollutant discharged from a point source through groundwater may be a “functional equivalent” of a direct discharge. Specifically, what happens to a discharged pollutant over the time and distance traveled to the WOTUS is critical to the “functional equivalent” analysis. It is possible for the pollutant composition or concentration to change sufficiently over the course of traveling to the WOTUS that it is not the “functional equivalent” of a direct discharge to WOTUS.

EPA also identified an additional factor that should be considered when performing a “functional equivalent” analysis – the design and performance of the system or facility from which the pollutant is released. This factor emphasizes the importance of a case-by-case analysis, understanding that the design and performance of a particular system or facility may in fact promote dilution, absorption or dispersion of a pollutant, among other considerations. EPA concluded its guidance with the following statement:

If a facility is designed and performs with a storage, treatment or containment system such as a septic system, cesspool or settling pond; if the facility is operating as a runoff management system, such as with stormwater controls, infiltration or evaporation systems or other green infrastructure; or if the facility operates water reuse, recycling or groundwater recharge facilities, and these system components in fact abate discharges of pollutants to WOTUS, such that the discharges either do not reach a WOTUS or because the discharge is not the “functional equivalent” of a direct discharge, it may be less likely that an NPDES permit would be required.

The Maui decision opened a new potential area for suits against facilities, including ag operations. For facilities subject to NPDES permitting, this guidance demonstrates the importance of factoring these considerations not only into the daily operations of facilities but also into design of the facilities and systems.

While it is unclear how the “functional equivalent” analysis will be applied to facilities, EPA’s guidance shows it will be a facility-specific analysis and owners and operators should be mindful of these factors as applied to their facilities.