Rotten Odor Traced to Salton Sea

RIVERSIDE - A strong sulphuric odor that repelled residents of Riverside County and neighboring counties was confirmed today to have emanated from the Salton Sea.

''We now have solid evidence that clearly points to the Salton Sea as the source of a very large and unusual odor event,'' said Barry Wallerstein, executive officer of the South Coast Air Quality Management District.

The stench hung on the air in Riverside and numerous other Inland Empire cities -- from Moreno Valley to Murrieta -- Monday morning after drifting into the region Sunday night.

Complaints came ''from a very wide area including the Inland Empire and much of the Los Angeles Basin,'' according to an AQMD statement, which noted that ''fish kills, algae blooms and other biologic conditions in lakes can cause strong odors.''

According to the agency, which monitors pollution levels in the region, technicians took air samples and field inspectors used odor surveillance techniques to isolate the location of the stink and results ''showed a clear progression of hydrogen sulfide levels, with the highest concentrations found at the Salton Sea and decreasing concentrations found as the distance increased from the sea.''

''This progression, or gradient, points to the Salton Sea as the source of the odor,'' Wallerstein said.

Organic decay, or dying plant and animal life, produces the unmistakable rotten-egg scent, officials said, pointing out that thunderstorms over the inland desert Sunday likely carried the stench from the stagnant Salton Sea to points farther west.

Riverside County Supervisors John Benoit and Marion Ashley noted during today's Board of Supervisors meeting that the foul smell has been a recurring problem in the Coachella and Imperial valleys for years and now the rest of Southern California was getting a taste of it.

The supervisors said the problem underscores the need for steps to improve conditions at the site.

According to the AQMD, the hydrogen sulfide fumes, which dissipated by early Monday afternoon, did not pose a health threat.

Unexplained foul odor reported throughout the Southland

Riverside - Officials continued their effort today to determine the cause of a foul odor that has been reported around the Southland from Palm Springs to Los Angeles, although several factors indicate the Salton Sea may be the source.

Onshore breezes today may keep the stench from reaching as far west as it did on Monday, said South Coast Air Quality Management District officials.

''Several sources have reported hot weather and a possible release of bacteria from the bottom of the sea due to winds there,'' SCAQMD Executive Officer Barry Wallerstein said. ''Those conditions could cause strong sulfur odors ... However, we do not have any definitive evidence to pinpoint the Salton Sea or any other source yet.''

Wallerstein added that ''...strong thunderstorm activity in the Salton Sea area and resulting high winds from the southeast could have pushed odors into the Los Angeles basin'' even though ''it is highly unusual for odors to remain strong up to 150 miles from their source.''

Investigators continue to work to determine the source. On Monday evening, they collected air samples throughout the Coachella Valley and at the Salton Sea, according to the AQMD.

''An analysis of those samples may provide further evidence of a possible source,'' according to a district statement.

The AQMD also sent field inspectors to the San Fernando Valley, Long Beach, Colton, Riverside, San Bernardino, Perris, Temecula, Banning, Palm Springs and La Quinta in an effort to pinpoint the source of the stench.

''A foul 'rotten egg-like' odor has been sensed across vast expanses of Southern California since early this morning,'' Brian Humphrey of the Los Angeles Fire Department said Monday. ''LAFD is not aware of any specific hazard associated with the odor.''

The AQMD received more than 200 complaints since midnight Monday reporting a strong, foul rotten egg odor. Most of the calls came from the Coachella Valley and elsewhere in Riverside County, but some came from San Bernardino, Los Angeles and Orange counties, according to the AQMD.

''Residents have complained from a very wide area including the Inland Empire and much of the Los Angeles Basin,'' district media relations manager Sam Atwood said.

''Fish kills, algae blooms and other biologic conditions in lakes can cause strong odors. Industrial facilities such as wastewater plants also can cause sulfur odors,'' according to the AQMD.

Some schools in the foothills areas of Los Angeles County implemented their ''rainy day'' schedule, which means activities normally taking place outdoors were moved indoors, said Monica Carazo of the Los Angeles Unified School District.