Introduction

The case of Los Angeles County Flood Control District v. Natural Resources Defense Council, Inc., et al. (133 S.Ct. 710, 2013) addressed a pivotal question under the Clean Water Act (CWA): Does the flow of water from a concrete channel within a river into an unimproved portion of the same waterway constitute a “discharge of a pollutant”? This case involved the Los Angeles County Flood Control District (District), which operates a Municipal Separate Storm Sewer System (MS4) that discharges storm water into navigable waters. Respondents, including the Natural Resources Defense Council (NRDC) and Santa Monica Baykeeper, alleged that the District violated its National Pollutant Discharge Elimination System (NPDES) permit by discharging polluted storm water, leading to water quality standards being exceeded in the Los Angeles and San Gabriel Rivers.

Summary of the Judgment

The U.S. Supreme Court reversed the Ninth Circuit Court of Appeals' decision, holding that the flow of water from an improved (concrete-lined) portion of a navigable waterway into an unimproved portion of the same waterway does not constitute a “discharge of a pollutant” under the CWA. This decision aligns with the Court’s earlier ruling in South Florida Water Management District v. Miccosukee Tribe (541 U.S. 95, 2004), which determined that transferring polluted water within the same water body does not amount to adding pollutants under the Act.

The Supreme Court found that the Ninth Circuit erred by holding the District liable based on downstream pollutant measurements, emphasizing that such transfers do not meet the statutory definition of a pollutant discharge. The Court remanded the case for further proceedings consistent with its ruling.

Analysis

Precedents Cited

The primary precedent cited in this judgment is South Florida Water Management District v. Miccosukee Tribe (541 U.S. 95, 2004). In Miccosukee, the Supreme Court held that the transfer of polluted water from one part of a water body to another does not constitute a discharge of pollutants under the CWA, as it does not involve adding additional pollutants to the water body. This case reinforced the principle that the mere movement of existing pollutants within the same water system does not trigger regulatory consequences under the CWA.

Additionally, the Court referenced Catskill Mountains Chapter of Trout Unlimited, Inc. v. New York (273 F.3d 481, 2001) to illustrate the interpretation of "adding" pollutants, emphasizing that transferring water within a body does not equate to adding new pollutants.

Legal Reasoning

The Supreme Court’s legal reasoning is anchored in the statutory language of the CWA, specifically the definition of "discharge of a pollutant," which is “any addition of any pollutant to navigable waters from any point source” (33 U.S.C. § 1362(12)). The Court interpreted "add" in its plain sense, meaning to join or unite without increasing the quantity of pollutants in the water body. Since the water merely flows from a concrete-lined (improved) section to an unimproved section of the same waterway, no additional pollutants are introduced; thus, no discharge has occurred.

The Court distinguished between the act of transferring water within a water body and the act of discharging pollutants from a separate point source into the water body. The critical point is that for a discharge to occur, there must be an addition of pollutants, not merely the movement of existing pollutants within the same water system.

Impact

This judgment has significant implications for municipalities and other entities operating MS4s and similar systems. By clarifying that internal water transfers within a waterway do not constitute discharges under the CWA, the ruling potentially limits the scope of regulatory oversight and liability for such entities. It reinforces the boundaries of the CWA, ensuring that only actions that add pollutants to water bodies trigger regulatory measures and require NPDES permits.

Additionally, this decision underscores the importance of precise monitoring and regulation of actual discharge points rather than focusing solely on downstream pollutant levels, which may be influenced by multiple sources.

Complex Concepts Simplified

Conclusion

The Supreme Court's decision in Los Angeles County Flood Control District v. NRDC provides a clear interpretation of what constitutes a "discharge of a pollutant" under the Clean Water Act. By affirming that the mere movement of water within the same water body does not amount to adding pollutants, the Court delineates the boundaries of regulatory authority under the CWA. This ruling not only reinforces existing legal precedents but also offers guidance for future cases involving water pollution and regulatory compliance. Entities managing stormwater systems can leverage this clarification to better understand their obligations and the scope of permissible operations under the CWA.