L.A. hasn’t had a good bath in years.
That means a lot of trash, muck and grime has built up on streets and in gutters around the region.
This week's rains are expected to wash much of that pollution into the Santa Monica and San Pedro bays, says Kirsten James with the nonprofit environmental group Heal the Bay.
Researchers from the Council for Watershed Health estimate that just an inch of rain across the entire region can produce up to 10 billion gallons of polluted runoff.
That’s the equivalent of 100 Rose Bowl stadiums filled with water tainted by oil, plastic trash, pesticides and other toxic materials.
James says bacteria left when pet owners don’t clean up after their animals is also a big problem when it is swept into the ocean by rain.
“That bacteria can stay near shore and cause beachgoers to get sick," she said, adding that marine animals also suffer when large amounts of unhealthy runoff suffuse their habitat.
"So there are a number of impacts from storm water pollution,” she said.
A study by the Council for Watershed Health found that half the water in a typical storm over the Los Angeles Basin becomes runoff.
The organization supports adding new infrastructure to allow the region to capture polluted runoff before it hits the sea.