Rains Ease as Crews Try to Contain Sewage Spill : Weather: Workers seek to confine 8 million gallons released during power outage. Wreckage of 100-vehicle pileup is cleared from I-15.

After battering Southern California with driving rain and tornado-like wind bursts, a swift-moving storm front slackened Saturday, while sanitation crews worked to contain a sewage spill in Los Angeles Harbor and residents mopped up debris-strewn streets.

Dense fog lifted over the Cajon Pass, where poor visibility contributed to a 100-vehicle chain-reaction pileup that killed one woman and injured 63 others Friday. Among the injured were some of the 53 sixth-grade students whose school bus was struck by a produce truck.

A series of weak and intermittent showers was expected today in advance of a larger storm system and gusting winds that meteorologists expect to move into the region by the middle of this week.

Steve Burback, a forecaster with WeatherData Inc., said today’s rain was expected to be significantly weaker than Friday’s tempest. Clouds will predominate until late Tuesday night, when a new storm system building in the Gulf of Alaska is expected to move into Southern California, bringing widespread rain and harsh winds.

“The rain will continue into Thursday and you could get amounts of well over two inches,” he said.

At times the heavy downpour and freakish winds that wracked Southern California on Friday played havoc with utility lines in the San Pedro area, cutting off electricity for 11 hours to Los Angeles’ Terminal Island Waste Water Treatment Facility. The power shortage--whose cause is unknown--froze machinery in one section of the plant, allowing 8 million gallons of partially treated sewage to flow into the harbor.

County health officials closed Inner Cabrillo Beach as a precaution and were awaiting the results of 24-hour tests to determine the degree of sewage contamination in the harbor. Terminal Island plant manager Clarence Mansell said the spill is apparently confined to the harbor and had not reached the Pacific Ocean.

“So far, it’s not spread over a large geographic area,” he said. “Cabrillo Beach is our only concern right now.”

The power shortage prevented the sewage from being neutralized by bacteria inside the plant--a process that is normally the final stage of treatment before the waste water drains into the harbor, Mansell said.

“We’ve never gone this long without power,” he said. “Obviously, the water’s not been treated to the degree we’d like, but we’re hoping enough solids were already filtered out that it will disperse in the harbor.”

Adding to the uncertainty, Mansell said, is the effect of waste water runoff from storm drains clogged by the rainfall.

In the Santa Clara River area, a rupture of a sewage line Saturday pumped from 360,000 to 400,000 gallons of raw sewage into the river, Los Angeles County sheriff’s deputies said. Rain and road erosion were blamed for the spill, which posed no danger to residents, officials said.

The pipe leaked for about six hours before work crews from various Los Angeles County departments were able to contain the spill and cap the pipe. The leak may take up to two days to repair completely, county officials said.

To the east of Los Angeles, traffic flowed freely through a section of Interstate 15 in the San Bernardino Mountains where a chain-reaction collision Friday left 100 vehicles--tractor-trailers, buses and cars--crushed together.

“It was all cleaned up by last night,” California Highway Patrol Officer Lorin Orchard said Saturday morning. “All the lanes are open, the wrecks are gone and we haven’t seen any fog today.”

Orchard said the San Bernardino coroner’s office had not identified a woman killed during the collision and were unable to determine whether the crash or a heart attack was the cause of her death.

Most of the 63 people injured during the collision had been treated and released from hospitals. Only seven remain hospitalized, none critically, Orchard said. Among them, he said, were a man with a broken jaw and a sixth-grader with a strained back.

Accident investigators believe the collisions began after a tractor trailer rig traveling south in the Cajon Pass jackknifed on the rain-slicked highway. Orchard added that the CHP’s investigative team would probably take another two to three weeks before drawing conclusions.

In the El Sereno area of Los Angeles, neighbors awoke Saturday to find their streets awash with debris. Loose shingles, aluminum siding and branches littered the 3500 block of El Sereno Avenue, where a whirlwind touched down briefly Friday afternoon, damaging at least 10 houses.

Several hours after the storm subsided Friday night, residents joined in an impromptu barbecue, drifting over to console one another and inspecting shattered windows, cracked roofs and mud-splattered walls. On Saturday morning, they began pitching in to repair the damage.

“It looked sad when I woke up this morning, man,” said Enrique Castillo, 35, a carpenter whose apartment windows were blown out and motorcycle was picked up by the raging wind. “Filth everywhere.”