Samuel B. Boxerman is a Partner with Sidley Austin LLP in the firm’s Washington, DC office and is the WLF Legal Pulse’s Featured Expert Contributor on Environmental Law and Policy.

Whether whiskey being poured from a bottle to a flask and then to a punch bowl would be regulated—whether the groceries you buy come from the store, or from your car, as that is the last place they were before you enter your house—and whether releases from one septic tank would have to be permitted, but not from a housing development with hundreds of septic tanks.  These are among the analogies discussed at oral argument before the U.S. Supreme Court as the Justices questioned counsel about how to interpret the Clean Water Act (CWA) in County of Maui vs. Hawaii Wildlife Fund.

As reported here previously, the case concerns a wastewater treatment plant operated by the County of Maui.  The plant is permitted to inject treated wastewater into underground injection wells—and some of that wastewater travels from the wells through groundwater to the Pacific Ocean, a half mile away.  At issue is whether the County needed a permit for the injected wastewater leaving the wells and reaching the ocean:  Does the CWA require a permit when pollutants originate from a point source (the wells) but are conveyed to a navigable water (the Pacific) via a nonpoint source (the groundwater).  The County has argued no, a discernible, confined, and discrete conveyance must carry the pollutant to be regulated.  The Ninth Circuit disagreed, holding that a permit would be required, so long as pollutants were “fairly traceable” from the wells to the ocean so that it was “the functional equivalent” of a discharge to a navigable water.  The respondent environmental groups support the lower court’s approach.

At argument, Justice Breyer, in questioning Maui’s attorney, asked whether the County’s reading would provide a “road map” for avoiding regulation, as a source could “just cut off” the discharge pipe before the stream.  Justice Kagan echoed that, stating that “nobody would ever have to get a permit” under petitioner’s approach.  Justice Sotomayor’s questioning also appeared to support respondent, suggesting the other laws petitioner pointed to are “remedial” while the CWA is “preventative” and “that’s why we give them a permit.”  Justice Ginsburg, meanwhile, asked how the respondent’s test differed from “direct hydrological connection” test adopted by the Fourth Circuit in the Upstate Forever case (also discuss previously here) that is also before the Court (but on hold for now).

Justice Kavanaugh questioned whether the County’s test was akin to the test rejected by late Justice Scalia in Rapanos, but also sought “some clear line for property owners” that would be objectively clear “up front” and not after much litigation.  In questioning respondent’s counsel, Justice Alito expressed concern “whether there is any limiting principle that can be found in the text and is workable and does not lead to absurd results.”  Chief Justice Roberts and Justice Gorsuch likewise each asked respondent to define a “limiting principle” on their approach, with Chief Justice Roberts noting the respondent’s “proximate cause” approach was “notoriously manipulable.”

It is often perilous to read the tea leaves of oral argument and predict how the Court might rule.  This case is no different, as the Justices revealed a range of views and much uncertainty about how they might interpret the Act.  The Court took the case, which often does signal an interest in reversing the lower court.  Yet, if Justice Kavanaugh’s reference to Rapanos suggests some inclination to find a middle ground, it could be the case that they are headed towards a ruling that would require permitting in certain circumstances beyond the scope advanced by Maui, provided a majority can coalesce around an appropriate limiting principle.  Stay tuned.