Oil Pipeline Spill Leaves 8-Mile Slick on River : Mobil: A rupture is blamed for the release of more than 63,000 gallons into the Santa Clara. It raises concerns of ground-water contamination in Ventura County.

A ruptured underground pipeline sent more than 63,000 gallons of oil oozing into the Santa Clara River at Valencia on Friday, leaving an eight-mile slick of sticky black crude that stretched into Ventura County.

Crews who battled sandy soil and a lack of roads leading to the western edge of the slick, near Piru, were expected to work around the clock to contain and clean up the oil. The crews, who used oil-absorbent booms and huge vacuums to suck up the mess, were expected to continue working at least three days. Long-term efforts to remove contaminated soil and brush could last for weeks.

Officials said the spill was caused by a large crack in a 21-year-old section of the pipeline.

The cleanup, to be financed by pipeline operator Mobil Oil Co., could cost $1 million, officials said.

The spill raised concerns of ground-water contamination in Ventura County, which depends on underground basins for 67% of its water.

Officials at the United Water Conservation District worried that water released from Lake Piru down Piru Creek and into the Santa Clara River would carry the oil and its toxic components to spreading grounds that recharge underground basins near Saticoy.

Those basins provide all or part of the water supply for about 300,000 people and 800 farms in Fillmore, Santa Paula, Port Hueneme, Oxnard and Ventura.

“We now have to put in ground-water monitoring wells to check for hydrocarbons,” Frederick J. Gientke, general manager at United, said. “We’re not going to put oil in the spreading grounds.”

Oil and its constituents contain the carcinogen benzene and other potentially harmful chemicals, officials at the Ventura County Environmental Health Department said.

“With oil, there is always the possibility that the light ends of the hydrocarbon molecules can migrate through the soil and contaminate the water,” Dana Determan, an environmental health specialist for Ventura County, said.

California Department of Fish and Game officials said they expected minimum damage to area wildlife, but at least five small fish were found dead in the slick, and two oiled ducks were retrieved from the river.

Mobil asked the Berkeley-based International Bird Rescue Service to set up an animal reclamation and rehabilitation center near the spill site to care for any animals caught in the oil.

Great blue herons and other water fowl, along with steelhead trout and other endangered species of fish, live in or along pools in the Santa Clara River, even though parts of the river are dry much of the year. But at its eastern end, the Santa Clara is fed by waste water from the Santa Clarita sewage-treatment plant, which continued to discharge effluent that carried the oil farther west into Ventura County.

Robert Mandel, the on-site supervisor for the Environmental Protection Agency, said the crews should work through the night to take advantage of the fair weather and contain the spill in as small an area as possible.

“This is one of the last free-flowing rivers in California,” he said, referring to the Santa Clara’s still unchanneled banks. “There is critical wildlife habitat here.”

Mandel said cleanup crews were working slowly and carefully with the booms and huge vacuum pumps so they would not disturb the wildlife.

Jim Carbonetti, a Mobil spokesman, said the pipeline is expected to be back in operation within 24 hours.

“The suspected cause (of the rupture) is exterior corrosion,” Carbonetti said. “There was an 18-inch-long split on the side of the pipe.”

The pipeline, which ruptured at 11:30 p.m. Thursday, carries crude oil from Kern County oil fields to a Mobil refinery in Torrance. The 92-mile-long pipeline has been plagued by seven other breaks and oil spills since 1986, and Mobil is in the process of seeking governmental approval to replace the pipeline with a high-tech system the company says will greatly decrease the chances of ruptures.

Tim Salles, a special projects manager for Mobil, said the pumping station shut down automatically when equipment detected a pressure drop in the pipeline. Company officials notified the Los Angeles County Fire and Sheriff’s departments of the leak at 1:20 a.m., about the same time residents began reporting the smell of natural gas.

Karen Guidi, assistant director of the Ventura County Office of Emergency Services, said the spill showed that the county’s recently developed oil-spill response plan was working.

“We didn’t need to activate as many of the resources as we planned on,” she said of the plan developed to combat spills at sea. “But this gave us an opportunity to test our notification system.”

The oil moved for about eight miles west in the river but the flow was stemmed by dirt dikes quickly made by firefighters and oil-absorbent booms placed across the river by work crews. Tanker trucks were being used to vacuum thick pools of oil off the river’s surface.

By Friday afternoon, the oil layer had thinned near Piru as workers removed the heaviest portions.

But cleanup crews, still hampered by a lack of access to the river with their large machinery, were rebuffed when they sought approval from United Water late Friday to move the cleanup operation from the Camulos Ranch, just east of Piru, west to Torrey Road, just south of the unincorporated community.

“Absolutely not,” came Gientke’s answer. He said the district must release water from Lake Piru down Piru Creek to help maintain the underground basins. Torrey Road is below the confluence of Piru Creek and the Santa Clara River.

The largest previous spills from the Mobil pipeline were in 1988 when two ruptures three weeks apart in Sherman Oaks and Encino spilled more than 130,000 gallons of crude oil into city sewers. Mobil spent more than $3.2 million to pay for cleanup costs, damages to property and fines to government agencies.

The pipe that ruptured, which has a 12-inch diameter, feeds out of a Mobil Oil Corp. pumping station next to the Valencia Golf Course, east of the Golden State Freeway near Magic Mountain.

Mobil wants to replace about 75 miles of the so-called M-70 Pipeline, which has a diameter ranging from 10 to 16 inches and has segments as old as 50 years. The new pipeline would increase the capacity by nearly one-half, from 63,500 barrels per day to 95,000 barrels per day. A barrel contains 42 gallons.

Times Staff Writers Julio Moran and Michael Connelly contributed to this report.