Legal Updates

EPA’s Maui Draft Guidance: Industry Left Wondering, “What is a ‘functional equivalent’ of a regulated direct discharge?”

As reported in our prior blog on County of Maui v. Hawaii Wildlife Fund, the Supreme Court punted on providing clear guidance to the regulated community on when a Clean Water Act Section 402 National Pollutant Discharge Elimination System (“NPDES”) permit is needed.  As a result, the EPA stepped in and issued a draft guidance memorandum on how to apply the decision on December 9, 2020. EPA explains, “This draft guidance places the functional equivalent analysis into context within the existing NDPES permitting framework and identifies an additional factor for the regulated community and permitting authorities to consider when evaluating whether and how to perform a ‘functional equivalent’ analysis.”

EPA asserts its memorandum “provides focused guidance to the regulated community and permitting authorities.”  Unfortunately, the document leaves many of the key questions unanswered.  Moreover, EPA expressly recognizes that this draft guidance does not have the force of law.  It is also unclear whether the guidance will survive the change in administrations.  Regulated entities will therefore not find much comfort in this guidance.

In short, the Maui decision held that an NPDES permit is needed where a point source[1] discharges pollutants that migrate through groundwater to waters of the United States if the discharge is the “functional equivalent of a direct discharge from the point source into navigable waters.”  It provided seven non-exclusive factors that could be considered, and then left it for the lower courts to further develop this “functional equivalent” test.

EPA’s draft guidance provides useful background on Maui and how to integrate the decision’s seven-factor test into a traditional NPDES permitting decision.  EPA explains when the “functional equivalent” test comes into play, and—more importantly—when it does not.  Basically, it is relevant only where there is a point source that actually discharges pollutants into groundwater and the pollutants ultimately reach waters of the United States.  The “functional equivalent” test and EPA’s new guidance then helps determine whether the source needs an NPDES permit for the discharge.

In its guidance, EPA sets forth an additional factor to consider along with the seven identified by the Supreme Court: “the design and performance of the system or facility from which the pollutant is released.”  For example, a septic system is designed to promote natural dispersion, dilution, and treatment so it is less likely to be considered the functional equivalent of a direct discharge even if some pollutant eventually reach waters of the United States through groundwater.

EPA’s guidance does not, however, provide details on how to apply the existing seven factors established by the Supreme Court.  Regulated entities will therefore still have to wait for the law to develop in the lower courts before they can have any measure of certainty about when they must have an NPDES permit for discharges into groundwater.


Tags: “functional equivalent,” Clean Water ActCWA, NPDES, WOTUS, Maui, EPA, “navigable waters”


[1] The CWA defines “point source” as “any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged.” 33 U.S.C. § 1362(7), (14).