Environment & Science

Pungent scent in air over wide area of So. Calif. still a mystery

Southern California air quality officials are still tracking the scent of a rotten-egg odor that filled the air from the Salton Sea in Imperial County to the San Fernando Valley in Los Angeles County.

The smelly air was first reported Sunday evening, but hundreds of people reported the stinky scent Monday over a wide area of the Southland.

“Several factors indicate that the Salton Sea may have been the source of these odors,” said Barry Wallerstein, executive officer for the South Coast Air Quality Management District (AQMD). “However we do not have any definitive evidence to pinpoint the Salton Sea or any other source yet.”

Fish die-offs at the Salton Sea, 150 miles southeast of Los Angeles, are caused by low oxygen levels in the water and receding shorelines. The odor can be strong, but Monday's foul smell was reported as far away as Palmdale and Lancaster, more than 150 miles north of the Salton Sea.

"It is highly unusual for odors to remain strong up to 150 miles from their source," Wallerstein said.

The AQMD sent field inspectors Monday to the San Fernando Valley, Long Beach, Colton, San Bernardino, Riverside, Perris, Temecula, Banning, Palm Springs, La Quinta and the Salton Sea in an effort to locate the source of the odor. The agency also collected a number of air samples Monday evening in several locations throughout the Coachella Valley and at the Salton Sea.

"We are in the process of analyzing those samples and hope to have results later Tuesday," said Sam Atwood, with the AQMD.

As of Monday evening, the AQMD said it had received about 225 complaints of sulfur- and rotten-egg odors.

Most callers were from the Coachella Valley and other portions of Riverside County as well as San Bernardino and Los Angeles counties. But between Monday night and Tuesday morning, only nine odor complaints came in to the AQMD.

AQMD officials predicted a strengthening onshore breeze might keep any additional odors from spreading as far west on Tuesday as they did on Monday.