When polluted storm water flows from a concrete-lined river channel to an unlined portion of the same river, does that movement of water constitute a “discharge of pollutants” under the Clean Water Act?

Answering “no” in a short five-page opinion, the Supreme Court reversed the Ninth Circuit Court of Appeals in its recent decision, Los Angeles County Flood Control Dist. v. Natural Res. Defense Council, Inc., No. 11-460, slip op. at *4 (Jan. 8, 2013) (Alito, J., concurring) (District). Citing its 2004 decision, South Fla. Water Management Dist. v. Miccosukee Tribe, 541 U.S. 95, 109-112 (2004) (Miccosukee), the Court held that “no discharge of pollutants occurs when water, rather than being removed and then returned to a water body, simply flows from one portion of the water body to another.” Id. *4. Accordingly, “the flow of water from an improved portion of a navigable waterway into an unimproved portion of the very same waterway does not qualify as a discharge of pollutants under the [Clean Water Act].” Id.

Although the case involved a citizen suit against the flood control district for alleged violations of its National Pollutant Discharge Elimination System (NPDES) permit, the narrow issue decided by the Supreme Court was of perhaps more concern to entities who do not hold an NPDES permit.

This is because the Clean Water Act prohibits a “discharge of pollutants” in the absence of an NPDES permit. If water moving from the channelized or otherwise modified portion of a river or stream to an unmodified portion constituted a “discharge of pollutants,” entities who owned or in some way controlled the modification—e.g., hydroelectric facilities, irrigation districts, drainage districts—might have been required to obtain NPDES permits.

The Supreme Court’s reaffirmation of its decision in Miccosukee should allay those concerns, particularly in circumstances in which water flows from a modified waterbody into the unmodified portion of the same waterbody. The Court did not address the related circumstance in which water is transferred from one waterbody to another, but note that the U.S. Environmental Protection Agency has promulgated a rule that exempts such transfers from the NPDES permit requirement if (1) the transferred water is not subjected to “intervening industrial, municipal, or commercial use” and (2) the act of transferring the water does not itself add pollutants to the water. See 40 C.F.R. § 122.3(i) (2012).

By: Michael Campbell, Wayne Rosenbaum and Ryan Waterman