Supreme Court rules on Clean Water Act wastewater case

The U.S. Supreme Court on April 23 determined that the Clean Water Act’s (CWA) requirement to obtain a National Pollutant Discharge Elimination System (NPDES) permit can apply to certain releases of pollutants that reach surface water through groundwater.

The case, County of Maui v. Hawai’i Wildlife Fund, determined for the first time that an indirect addition of pollutants into surface waters requires a NPDES permit when it “is the functional equivalent of a direct discharge.”

This “functional equivalent” test will require the Environmental Protection Agency (EPA), courts, and litigants to work out over the coming months and years precisely what indirect additions require NPDES permits.

In a 6-3 decision, Justice Stephen Breyer, writing for the majority, rejected both the U.S. Court of Appeals for the Ninth Circuit and the litigants’ proposed tests to define the circumstances under which the CWA requires a NPDES permit. The Ninth Circuit held that the County of Maui’s releases of treated wastewater from injection wells that reached the Pacific Ocean via groundwater required a permit because they were “fairly traceable” back to a point source.

The Supreme Court narrowed the very broad test that the Ninth Circuit Court of Appeals developed in its County of Maui decision. Under the narrower standard adopted by the Supreme Court, if pollutants are fairly traceable “‘from the point source to a navigable water such that the discharge is the functional equivalent of a discharge into the navigable water,’” then the CWA would require a permit.

The court noted that the Ninth Circuit’s “fairly traceable” test “may well allow EPA to assert permitting authority over the release of pollutants that reach navigable waters many years after their release … and in highly diluted forms.”

The court rejected this broad reading, noting, among other reasons, that the structure of the statute indicates that, as to groundwater pollution and non-point source pollution, Congress intended to leave substantial responsibility and autonomy to the states.

In addition, the court rejected the County of Maui’s and the Solicitor General’s proposed standards. The county had argued that the CWA requires a permit only when the original point source is the direct “means of delivering” pollutants to surface waters. The Solicitor General, in support of the county, urged that the CWA categorically excludes from the NPDES program all releases of pollutants into groundwater.

The court found that both of these interpretations were inconsistent with the statute’s text and, if adopted, would create a statutory loophole that could allow dischargers to evade the CWA’s permitting requirement simply by relocating their discharges.

The court said that the phrase “functional equivalent” best captures, in broad terms, those circumstances in which Congress intended to require a federal permit. 

“That is, an addition [of a pollutant] falls within the statutory requirement that it be ‘from any point source’ when a point source directly deposits pollutants into navigable waters, or when the discharge reaches the same result through roughly similar means.”

The court identified seven—nonexclusive—factors “that may prove relevant” to assessing whether the functional equivalent of a discharge has occurred:

  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.

The court’s majority explained that the first two factors—time and distance— “will be the most important factors in most cases, but not necessarily every case.”

While the court’s decision is focused on discharges conveyed by groundwater, its ruling could have implications for other nonpoint conveyances (such as surface runoff).   

In adopting this revised approach, the majority specifically acknowledged “that a more absolute position, such as the means-of-delivery test or that of the Government or that of the Ninth Circuit, may be easier to administer.”

It is unclear how the factors identified by the court will be weighed and interpreted. But the court invited the federal courts and EPA to provide further guidance on how the test would work in practice.

The majority explained that the courts may arrive at a more refined standard through “the traditional common-law method” of establishing principles in individual cases.

The court also invited EPA to “provide administrative guidance” in a variety of ways, including through rulemaking.

The decision is available here.