A federal appeals court dealt Los Angeles County a blow on Thursday in a long-running lawsuit over storm-water pollution when it issued an opinion that the county is liable for excessively high levels.
Environmental groups sued the county and its flood-control district in 2008 over pollution in the Los Angeles and San Gabriel rivers, saying the entities had violated storm-water permits based on high pollution readings at monitoring stations in the rivers.
County officials argued that they are not primarily to blame, because dozens of cities discharge polluted runoff upstream from the monitoring sites.
In 2011, the U.S. 9th Circuit Court of Appeals ruled that the county was liable for pollution in the rivers.
The county appealed the case to the U.S. Supreme Court, which ruled in January that water flowing from one "concrete" section of the river to another section cannot be deemed a "discharge" of pollutants and sent the case back to the appeals court. The high court did not rule on other issues raised in the lawsuit.