Mysterious Stinks Fouls Air In San Francisco

San Francisco police said they were inundated with phone calls Friday evening from people reporting a foul odor in the air.

People contacted by KTVU said the stench smelled like manure.

The Department of Public Works said a check of sewage plants didn't uncover any problems.

While complaints came from all corners of the city, most seemed to originate in the western neighborhoods near the ocean.

Surfer Jody Edmondson said, "The smell was putrid, it smelled rotten. There was something very rotten smelling."

There are a couple of theories about the origin of the smell.

The environmental group Baykeeper said the city has been cleaning sewer lines near Mission Bay and suggested that that work may be to blame.

There also is a red tide or algae bloom along the coast that might be the culprit.

Red tide is a massive concentration of microscopic plankton and when the organisms die off, they can produce a strong odor.