Federal Court Says County of Maui “Effectively Discharging” Pollutant in Violation of Clean Water Act

July 26, 2021 | Kitt Tovar Jensen

On July 26, 2021, the District Court of Hawaii considered whether the County of Maui must obtain a National Pollution Discharge Elimination System (NPDES) permit for releasing pollutants into injection wells a half a mile from the ocean. On remand, this district court, using factors set forth by the Supreme Court, held that the circumstances surrounding how the Lahaina Wastewater Reclamation Facility (LWRF) conveyed pollutants through groundwater was the “functional equivalent of a discharge.” Therefore, it granted the plaintiffs’ motion for summary judgment. This case is Hawaii Wildlife Fund v. County of Maui, 2021 WL 3160428 (D. Hawaii, July 26, 2021).


Since 2006, the LWRF has treated sewage for the city of Lahaina before moving the wastewater into four injection wells. The wastewater mixes with groundwater in the underground wells and indirectly makes its way to the Pacific Ocean. In 2012, several environmental groups brought this citizens’ suit claiming that County is in violation of the Clean Water Act (CWA) because wastewater is “discharged” from the wells into the Pacific Ocean without an NPDES permit.

The District Court of Hawaii agreed finding that the indirect groundwater discharge was “functionally equivalent to a discharge into the ocean itself.” Hawaii Wildlife Fund v. County of Maui, 24 F.Supp.3d 980 (D. Hawaii 2014). On appeal, the Ninth Circuit affirmed, but created a “fairly traceable” test to conclude that a NPDES permit was necessary. Hawaii Wildlife Fund v. County of Maui, 886 F.3d 737, 749 (2018).

The Supreme Court granted certiorari. After setting forth relevant factors to determine whether there was a functional equivalent of a discharge, the Supreme Court vacated the Ninth Circuit decision and remanded the case. Hawaii Wildlife Fund v. County of Maui, 140 S. Ct. 1462 (2020). On remand, both parties provided “voluminous stacks of paper” to support their arguments about whether the wells were a functional equivalent of a direct discharge. Although the discharge was indirect, the district court found that the wells effectively discharged pollutants into the Pacific Ocean. Thus, it held that the County must obtain an NPDES permit.

The “Functional Equivalent of a Direct Discharge” under the Clean Water Act

The Clean Water Act prohibits the discharge of a pollutant into any navigable waters from a point source without an NPDES permit. See 33 U.S.C. §§ 1311, 1342. In this case, neither party disputes that the wastewater is a “pollutant,” the Pacific Ocean is a “navigable water,” or that the treatment facility is a “point source” under the CWA. However, the parties dispute whether the wells “discharge” pollutants.

To determine whether there is a “functional equivalent of a direct discharge, the Supreme Court set forth seven non-exclusive factors. These include:

  • Transit time;
  • Distance traveled;
  • The nature of the material through which the pollutant travels;
  • The extent to which the pollutant is diluted or chemically changed as it travels;
  • The amount of pollutant entering the navigable waters relative to the amount of the pollutant that leaves the point source;
  • The manner by or area in which the pollutant enters the navigable waters;
  • The degree to which the pollution (at that point) has maintained its specific identity.

Id., 140 S. Ct. at 1476–77. While several other cases have addressed these factors since the Supreme Court’s decision in 2020, this is the first case primarily focused on their application.

Factors Weighing in Favor of Requiring a NPDES Permit

The district court found that many of the Supreme Court factors weighed in favor of requiring an NPDES permit. The Supreme Court stated that the first two factors, transit time and distance traveled, would generally be the most important factors. As such, the district court paid particular attention to those factors.

According to a 2013 Tracer Dye study, pollutants on average reach the ocean in 14 to 16 months, but can enter the ocean in as little as 84 days. The district court noted the Supreme Court’s example that a pollutant taking “many years” to reach a navigable water would not require a pollutant. Similarly, the district court found that the distance of the point source in this case is very different than the Supreme Court’s reference to a point source 50 miles from a navigable water. Here, the wells are located less than 1.5 miles away from the ocean. The court found that the short time and distance weighed in favor of requiring a permit.

Other factors also weighed in favor or requiring a permit. For example, it is uncontested that 100 percent of the wastewater leaving the LWRF reaches the ocean eventually. Additionally, the wastewater, although diluted, continues to maintain its specific identity as polluted water.

Lastly, the district court found an additional factor weighed in favor of requiring an NPDES permit. While it is unknown where 98 percent of the groundwater is discharged, the amount of wastewater discharged in monitored areas of the ocean is substantial. After a few months, millions of gallons of wastewater would be discharged. Even though an NPDES permit is required for the discharge of any pollutant, the district court concluded that “[i]n short, raw numbers matter without regard to the percentage of the total.”

Factors Weighing in Favor of No Permit

Conversely, the district court determined that two factors did not weigh in favor of requiring an NPDES permit. First, the wastewater did not flow directly through a pipe but rather through material such as volcanic rock. The wastewater would become diluted as it mixed with groundwater and other substances, thus significantly reducing the amount of pollutants which are released into the ocean.

The district court also addressed the EPA’s January 2021 guidance memorandum which identified an additional factor of system design and performance. Although the guidance is not legally binding, the EPA believed it may be relevant when performing a “functionally equivalent” analysis. Because the district court already considered the system and design of the LWRF, it found that this proposed factor did not play a role in this case.

Balancing of Factors

In conclusion, the district court found that the LWRF is discharging enormous amounts of pollutants into the Pacific Ocean. Relying on the relevant factors, the record showed that pollutants entered a navigable water from the LWRF over a relatively short time and distance. Although some factors weighed in favor of the County, many other factors did not. Thus, the district court held that the County of Maui was required to obtain an NPDES permit.