Sewage Spills, Rain Close 100 Miles of Beach : Environment: Areas from Ventura County to the Mexican border are posted with health warnings. Unsafe bacteria levels may last for seven days, officials say.

An untimely and unlucky combination of tropical storms and faulty piping led to Southern California’s biggest beach quarantine in recent memory, with nearly 100 miles of coastline placed off limits by health authorities due to sewage spills.

Officials said Wednesday that the beaches would remain closed at least until the weekend, and if the rain persists the quarantine could remain in effect indefinitely.

The affected coast is in Los Angeles County, where all 76 miles of oceanfront were quarantined Monday because of a rain-triggered sewage spill, and the southernmost 20 miles of beach in San Diego County where a severed outfall pipe has spewed sewage into the surf for more than a week.

“This is one of the worst pollution situations we’ve seen in a long, long time,” said Lisa Weil, policy director of the American Oceans Campaign. “These spills should serve as a wake-up alarm to us that our system . . . and needs attention.”

Beaches in Orange, Ventura and Santa Barbara counties were not covered by the closure orders.

Ventura County sewage treatment plants managed to handle the rain-swollen inflows Monday without backing up and discharging raw sewage, county health officials said.

But Ventura’s treatment plant near the mouth of the Santa Clara River ran at close to peak capacity for nearly two hours Monday night. Plant workers manipulated the flows to ease the temporary strain on the system.

“I had three people stay overnight, and we handled it,” said city Sanitation Supt. Dan Rayburn.

Test results from water samples collected off Los Angeles County beaches were not yet available Tuesday, but health officials said that levels of disease-causing bacteria undoubtedly had soared to thousands of times the safe limit.

As a precaution, they urged surfers, swimmers and waders to stay out of the water on all beaches in Los Angeles County. . Health officials said the quarantine would only be lifted when tests show bacterial levels have dropped to normal.

“The soonest we would open the beaches would be in four days, and I would estimate it would be more like seven days,” said Richard Kevadjian, a division chief for the Los Angeles County Department of Health Services. “This is a very large volume of sewage . . . We’ve never had a discharge this large.”

In San Diego County, the waters are likely to be off limits much longer. A broken pipeline has been spewing 180 million gallons of partially treated sewage into the sea each day since Feb. 2, and work crews--hampered by storm-tossed seas--estimate that $10 million worth of needed repairs will not be complete until April 4.

Although bacteria readings had declined somewhat Tuesday, 20 miles of coastline from Imperial Beach north to the San Diego River remained under indefinite quarantine.

In Los Angeles County, officials blamed an unfortunate confluence of events for the record-level spill that fouled the coastal waters.

The problem apparently began at the Donald C. Tillman Water Reclamation Plant inside the Sepulveda Dam Basin, where flooding Monday caused an electrical short that shut down pumps.

Workers turned to their backup system--rerouting millions of gallons of raw sewage through a 70-year-old line to the Hyperion Treatment Plant near El Segundo. But that line was already full--its contents swollen by rainwater that typically leaks into the sewage system during heavy storms.

Officials then invoked a second relief system--diverting sewage from the overloaded pipe into holding tanks beside Ballona Creek in Culver City. But the volume of sewage and rain runoff was too great, and workers Monday were forced to release more than 23 million gallons of diluted sewage into Ballona Creek, which enters the ocean at Marina del Rey.

As the rains persisted Tuesday, the releases continued and the total spill reached 32 million gallons.

The spill was the largest into Ballona Creek since the holding basins were constructed by the city of Los Angeles in 1986, Kevadjian said. The largest previous spill, he said, was about 7.5 million gallons--or less than one-fourth the size of this one.

Improvements now under way--namely, a new $120 million pipeline--should prevent similar spills in the future, officials said. But environmentalists lamented the slow progress on the pipeline and challenged the city’s practice of chlorinating the sewage as it spills into Ballona Creek.

Mark Gold, staff scientist for Heal the Bay, argued that the chlorine treatment probably is not enough to kill disease-causing organisms but does harm marine life.

On Tuesday, the Los Angeles County Board of Supervisors approved a policy requiring officials to immediately warn the public of hazards after sewage spills, heavy rains and environmental accidents.

At the quarantined beaches Tuesday, bright yellow signs warned bathers of the contaminated waters and lifeguards added emphasis with messages broadcast over their public address systems. Still, all the advice in the world didn’t keep “the dyed-in-the-wool boogie boarders, surfers and ‘polar bears’ out,” according to Don Rohrer, the county’s chief lifeguard.

Times Staff Writers Mark Platte and James Rainey contributed to this story.