In County of Maui v. Hawaii Wildlife Fund, the US Supreme Court held discharges from point sources that travel through groundwater to surface water require a Clean Water Act (CWA) permit when the discharges are “the functional equivalent of a direct discharge.”  Functional equivalency occurs “when the discharge reaches the same result through roughly similar means.”

Factors for Lower Courts to Consider
The Court recognized the holding will be a challenge for lower courts to apply and stated the relevant factors may 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, (7) the degree to which the pollution (at that point) has maintained its specific identity.  Time and distance will be the most important factors in most cases, but not necessarily every case.”

County’s Discharge May Be Equivalent to a Direct Discharge
The County of Maui disposes 3 to 5 million gallons of wastewater per day via four underground injection wells.  A study on two of the wells found that 64% of the wastewater eventually reached the ocean, approximately 880 yards away, with a travel time of at least 84 days.  Also, the eventual discharge to the ocean is at two clusters, each only several yards wide, with very little discharge between or around the clusters.

I predict the County of Maui will lose on remand under the “functional equivalent” standard.  A lower court will probably view millions of gallons discharged to the ocean per day, at these identifiable clusters and constituting 64% of the wastewater injected, as the functional equivalent of a direct discharge, even if the wastewater must travel 880 yards over 84 or more days to reach surface water.

Other cases with less compelling facts may result in courts determining the discharges do not require CWA permits.  It will probably take years and many decisions before dischargers, agencies, and courts understand how to apply this “functional equivalent” test.

For a link to the Supreme Court’s opinion https://www.supremecourt.gov/opinions/19pdf/18-260_jifl.pdf.