The Ninth Circuit Court of Appeals has ruled that Los Angeles County’s Flood Control District (L.A. County) is liable for contaminated stormwater runoff that its storm drains channel into rivers, harbors and eventually the Pacific Ocean. NRDC v. County of Los Angeles, No. 10‑56017 (9th Cir. 3/10/11). So ruling, the appellate court reversed, in part, a district court decision which concluded that plaintiffs lacked evidence to prove L.A. County caused the discharges that violated the terms of its CWA NPDES permit. NRDC v. Los Angeles County, No. 08‑1467 (C.D. Cal. 3/2/10).

Plaintiffs filed the lawsuit in 2008 to force defendants to address the runoff that sends tons of trash and other pollutants into the nearby rivers and ocean, especially following heavy rains. Stormwater monitoring data the county collected in 2006 and 2007 showed dozens of violations of the NPDES limits for fecal bacteria, cyanide, heavy metals, and other pollutants. Defendants argued that due to difficulties in regulating separate municipal storm sewers, they should be subject to “less rigorous” enforcement under the NPDES permitting system. They contended that the storm drains only channeled pollutants created by other municipalities or industrial NPDES permittees and, therefore, they should not be liable for those discharges.

The appellate court disagreed with L.A. County, ruling that defendants had an obligation to clean up pollution in their storm drain system. According to the court, “the Clean Water Act does not distinguish between those who add and those who convey what is added by others ‑‑ the Act is indifferent to the origination of water pollution.” According to press reports, defendants will seek a rehearing from the appellate court. See BNA Daily Environment Report and The Los Angeles Times, March 11, 2011.