Southern California beachgoers are being warned about debris, trash and bacteria near storm drains and rivers as a powerful storm soaked the region.
LA County health officials cautioned swimmers and surfers to stay away from sites where rain could push debris and trash from city streets and mountain areas into the water.
The runoff may contain harmful chemicals and bacteria that could contaminate the water. The struggle to contain that runoff and recycle it continues to be a challenge for Southern California as billions of gallons of water are flushed out with each heavy storm.
Local news from across Southern California
"An average rain storm, we lose 10 billion gallons of water to the sea," said Sarah Sikich with Heal the Bay. "Our wet weather is really when the largest pollutants are flushed out into the bay."
But a runoff filter near the Santa Monica Pier helps collect some of the trash before it goes to the ocean.
"We're screening it, separating out all the solids," said Neal Shapiro, who helps coordinate watershed programs for Santa Monica.
One such program, the Santa Monica Urban Runoff Recycling Facility, captures and recycles runoff from sprinklers and other sources not related to rain.
"We use it for spray irrigation and for toilet flushing," Shapiro said.
Areas of SoCal beaches that are not near discharging storm drains, creeks and rivers are not included in the advisory, which is in effect until Thursday at 6 p.m.