Skip navigation
Annenberg School of Communication and Journalism University of Southern California
Southern California

Unsafe ocean conditions after rainfall

Experts are calling many beaches bacteria breeding grounds after heavy rain.  Swimming in oceans after rain is a risk, according to experts

Text by Hayden Coplen

Yesterday's rains brought concerns about beach water contamination.

Beaches can be contaminated with excess amounts of toxins and trash for up to three days after a rainstorm, according to a spokesperson from non-profit organization Heal the Bay.

“This is a serious health hazard to people in the water,” said the group’s spokesperson Matt King. “Just because the beach may look clean, doesn’t mean it is clean.”

The water can be littered with untreated pesticides, animal waste, and even human viruses. Risk of encountering any of those is greatly increased within 72 hours of a significant rain.

The kinds of illnesses frequently contracted while people are in contaminated water are upper respiratory infections, gastrointestinal diseases, and skin rashes.

Heal the Bay works year-round to make people aware of the risk of swimming in polluted water.

“There are steps people can take in their daily lives to make sure they aren’t contributing to the problem,” King said.

He cites cleaning up after your dog, properly disposing of household chemicals, and picking up excess waste as simple solutions to avoid the spike in pollution following a rain storm.

The organization also recommends never swimming within 100 yards of a storm drain or letting children play in puddles, which can be a breeding ground for bacteria.

You can visit to see the weekly grade of your local beach.

Leave a comment

We've Moved!

By Sam Bergum
01/21/16 | 11:09 a.m. PST

Visit us at!

USC Basketball Knocks Off Rival UCLA 89- 75

By Scott Cook
01/14/16 | 12:05 a.m. PST

USC defeats UCLA with stellar play from their Freshmen. 

Holiday Bowl - USC vs Wisconsin Post-Game Press Conference

Su'a Cravens: "It's the players that need to step up"

Darreus Rogers: "It comes down to the players"

Trojans Fall to Wisconsin in the Holiday Bowl 23-21

We detected that you might be on a mobile device such as an iPad or iPhone. Sorry, at this time the video box is only visible on desktop computers.