(CN) - Los Angeles County and its flood-control district are responsible for discharging polluted stormwater runoff into the Los Angeles and San Gabriel Rivers, which then wash the raw sewage, urban trash and other pollution to the Pacific Ocean, the 9th Circuit ruled Thursday.
An appeals panel in Pasadena reversed a federal judge's ruling that the Natural Resources Defense Council and Santa Monica Baykeeper had failed to show evidence that the county allowed polluted stormwater to flow unimpeded into the two rivers.
The three-judge panel did, however, uphold the lower court's ruling that let the county off the hook for polluted runoff discharged into the Santa Clara River and Malibu Creek, finding that the plaintiffs lacked evidence that those pollutants passed through drainage systems controlled by the county.
The system that carries stormwater runoff - polluted with trash, metals, used oil, raw sewage and other contaminants - includes some 2,800 miles of storm drains and 500 miles of open channels. Known as the MS4, the system runs from the streets and parking lots of urban Los Angeles County to the rivers and the ocean. It passes through numerous separate municipalities and receives runoff and discharges from thousands of unmonitored entities.
No comprehensive map of the storm-drain system exists, according to the ruling, making it a "Sisyphean" task to assign blame for specific pollutants.
The parties agreed that pollution levels in all four rivers - which drain into the Pacific Ocean at San Monica Bay, Los Angeles Harbor and Long Beach Harbor - exceed those allowed by the county's National Pollutant Discharge Elimination System permit.
Between 2002 and 2008, four monitoring stations showed "hundreds of exceedances of the permit's water-quality standards," the ruling states. In the Los Angeles and San Gabriel Rivers alone they found high levels of aluminum, copper, cyanide, fecal coliform bacteria and zinc - pollutants which in turn showed up at popular Surfrider Beach in Malibu.
The NRDC and Baykeeper sued Los Angles County and the Los Angeles County Flood Control District over the permit violations in 2008.
Los Angeles argued that there was no direct evidence, given the Byzantine nature of the stormwater system, to show that it was responsible for the pollution.
U.S. District Judge Howard Matz granted summary judgment to the county and the district, ruling that the plaintiffs had not provided enough evidence that the pollutants had been under the defendants' control.
On appeal, the three-judge panel reversed in part and affirmed in part. It found clear evidence that the county and district had polluted the Los Angeles and San Gabriel Rivers, but agreed with the lower court that the evidence related to the two other rivers was wanting.
"Plaintiffs provided evidence that the monitoring stations for the Los Angeles and San Gabriel Rivers are located in a section of MS4 owned and operated by the district and, after stormwater known to contain standards-exceeding pollutants passes through these monitoring stations, this polluted stormwater is discharged into the two rivers," Judge Milan Smith wrote for the court.
"Plaintiffs, however, failed to meet their evidentiary burden with respect to discharges by the district into the Santa Clara River and Malibu Creek," Smith continued. "Plaintiffs did not provide evidence sufficient for the district court to determine if stormwater discharged from an ms4 controlled by the district caused or contributed to pollution exceedances located in these two rivers.
"Similarly, Plaintiffs did not delineate how stormwater from MS4s controlled by the county caused or contributed to exceedances in any of the watershed rivers."
Read the Top 8
Sign up for the Top 8, a roundup of the day's top stories delivered directly to your inbox Monday through Friday.