How the Los Angeles County Flood Control District MS4 Case Supreme Court Loss is a Win for the Clean Water Act

The Supreme Court ruled today that the 9th Circuit committed a legal error in holding the Los Angeles County Flood Control District liable for violations of its Clean Water Act (CWA) "municipal separate storm sewer system" (or MS4) pollution discharge permit. The suit, Los Angeles County Flood Control District v. Natural Resources Defense Council, had been initiated by NRDC and allied environmental groups, and its victory below was reversed. A loss for the environment? Actually, the careful and narrow Supreme Court ruling dodged a potential weakening of the CWA, and appears to have left open for consideration whether conceded permit violations by the Los Angeles County District meant it deserved to be held liable. The case potentially could have weakened the centrality of self-reported discharge permit violations and decades of rulings that such violations result in strict liability. The Court, however, dodged such a result, explicitly leaving that issue open in reversing and remanding the case. [Disclosure - I played a limited role in advising the plaintiff-respondent NRDC in this case.] The case involved numerous self-reported water quality violations by the Los Angeles County Flood Control District. The District, and numerous other municipalities discharging stormwater into the same water bodies, were together allowing too many pollutants to flow into the Los Angeles and San Gabriel Rivers, degrading the water bodies more than allowed in the District permit The 9th Circuit, however, wrote an opinion revealing discomfort with holding the District liable if there was no proof that the Los Angeles County District itself was responsible for such exceedances. And in so doing, the 9th Circuit made either a legal or factual error about the location of the CWA monitoring stations and the ability to attribute causation for violations to the Los Angeles County District. Furthermore, as the District argued before the Supreme Court, parts of the 9th Circuit ruling could be read to violate the Supreme Court's 2004 Miccosukee decision, which held that so-called discharges that just move polluted water from one part of a water body to another part of the same water body are not "discharges" at all. The Court granted the petition for a writ of certiorari on whether the District could be held liable after Miccosukee for so-called discharges that actually involved movement of polluter waters within the same water body. Before the Supreme Court, parties on both sides (including NRDC), and the United States in its amicus brief, agreed that there couldn't be liability for water pollutant movements within the same waterbody And today the Supreme Court agreed, restating the basic conclusion in Miccosukee.