In April 2020, the Supreme Court issued its opinion in County of Maui v. Hawaii Wildlife Fund et al., 140 S. Ct. 1462 (2000), vacating the Ninth Circuit’s decision.  The appeals court had affirmed a district court’s finding of Clean Water Act (“CWA”) liability for the County’s alleged failure to obtain a discharge permit for subsurface releases of pollutants that reach navigable waters by way of groundwater.  In vacating the judgment below, the Supreme Court rejected the Ninth Circuit’s conclusion that a discharge permit is required where pollutants reaching navigable waters are “fairly traceable” to a point source.  It set forth a new standard for determining when a source needs an NPDES permit:  “the statute requires 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.”  Id. at 1468 (emphasis added).

Recognizing that this statement “does not … clearly explain” when a source may need an NPDES permit, the Court set forth “some of the factors that may prove relevant” in any given case: (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 (at that point) has maintained its specific identity.  Id. (emphasis added).

To date, we are aware of two district courts that have applied the County of Maui factors in evaluating a plaintiff’s CWA claim.  In Cottonwood Envtl. et al. v. Big Sky Water & Sewer District (D. Mont. Mar. 23, 2021), the plaintiffs alleged that the District was releasing pollutants from holding ponds into a nearby river “both hydrologically and through the earthen walls of the holding ponds” without an NPDES permit.  After a period of discovery, the plaintiffs filed a motion for preliminary injunction, seeking relief that would effectively “disable [Big Sky’s] ability to treat wastewater from the Big Sky community.”  On March 23, 2021, the district court denied the injunction because plaintiffs failed to establish a likelihood of success or irreparable harm.

In considering the plaintiffs’ motion, the court described the pathway of the pollutants as follows:  “from the ponds, to [a] golf course, to the groundwater, and then to the West Fork of the Gallatin River.”  The court applied County of Maui to this “indirect discharge,” considering whether it “represents the functional equivalent of a direct discharge.”  According to the court, this analysis requires a “fact-intensive inquiry of the discharge at issue.”

The court found it “unlikely that [p]laintiffs’ claims w[ould] succeed based on the record presented.”  In particular, although plaintiffs introduced “evidence of elevated nitrogen in the West Fork of the Gallatin River,” the “origins of that nitrogen [were] unclear from the record presented.”  Moreover, plaintiffs’ elevated nitrogen samples from the Gallatin River did not “provide the kind of time, distance, and dilution data” that is required when evaluating the County of Maui factors.  The court also found irreparable harm lacking in part because plaintiffs “fail[ed] to present the irreparable harms that would remain at the West Fork of the Gallatin River after the alleged pollutants wash away.”

On May 21, 2021, the Magistrate Judge issued a decision in Peconic Baykeeper et. al. v. Harvey (E.D.N.Y.), recommending that the parties’ cross-motions for reconsideration, in light of County of Maui, be denied in part.  In this case, the plaintiffs allege that New York’s operation of certain septic systems violates the CWA because pollutants from those systems enter surface water through groundwater without authorization.  According to the plaintiffs, the septic systems are 23 feet to 880 feet from surface waters and pollutants from the systems enter those waters within weeks to 2.5 years.

The Magistrate Judge applied County of Maui and found that triable issues of fact precluded summary judgment for the plaintiffs.  While the Magistrate Judge observed that pollutants from the septic systems are a “short distance” from navigable waters and “often only take a few weeks to reach those waters,” he noted that the other Maui factors were “sharply in dispute to such an extent that they outweigh the time and distance factors such that summary judgment should be denied.”  In doing so, the Magistrate Judge highlighted the parties’ conflicting expert opinions on the “proportion of discharged pollution that actually reaches surface waters”; whether the pollutants are “substantially impeded on … their way to navigable waters”; and “the manner and area of the pollutants’ entry into navigable waters.”

Although many more decisions applying County of Maui are likely in the short and long term, these first two district court decisions demonstrate the highly technical and fact-intensive nature of the Maui inquiry, which may make it difficult for plaintiffs to prove their CWA claims under County of Maui without a full-blown trial on the merits.