What's That Smell? Powerful Odor Reported North of LA Is Likely Due to Dying Algae

Residents in communities north of Los Angeles reported a strong foul odor Tuesday morning that's likely due to a natural process along Southern California's shoreline.

Did you smell it? Let us know.

The Southern California Gas Company said it began received calls from people in Valencia, Canoga Park, Chatsworth, Simi Valley and nearby communities around 7 a.m. Social media posts also indicated a strong odor in parts of the San Fernando Valley.

SoCalGas Crews investigated the company’s facilities, but did not detect above-normal methane readings, the company said.

It might be a little bit gross to go to the beach in the next couple weeks.

Valerie Burkholder, Aquarium of the Pacific

The South Coast Air Quality Management District received complaints and dispatched inspectors, the agency said in a statement. Preliminary data did not show elevated levels of methane.

So what is it?

The stench wafting through the communities comes at the same time as coastal communities report the rotten odor of a dying algae bloom. The unpleasant odor is produced by the same microorganisms that provided Southern California with bioluminescent light shows this spring. 

“Now, the plankton that’s responsible for that has started to die off,” said Aquarium of the Pacific marine biologist Valerie Burkholder. “It might be a little bit gross to go to the beach in the next couple weeks.”

It will likely be a while before the odor diminishes.

“We’re smelling it in so many places right now, we think, because of how strong the onshore breeze has been over the last couple of days,” said NBC4 forecaster David Biggar. “There’s a lot of this westerly wind that carries all that cool, refreshing air from the ocean, but it also brings any smells associated with it.”

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