Oil Spill Could Endanger Drinking Water of 300,000 : Pollution: Officials will drill into the Santa Clara riverbed to see if carcinogens have reached the underground basins.

Oil from a broken pipeline is seeping into the sandy Santa Clara riverbed and may contaminate ground-water basins that provide drinking water to 300,000 Ventura County residents, officials said Saturday.

Water officials plan to drill wells into the river bottom and won’t know until mid-week whether carcinogens in dangerous amounts have reached the water supply, said Frederick J. Gientke, general manager of United Water Conservation District.

Meanwhile, six giant vacuums continue to clean up 63,000 to 84,000 gallons of heavy crude oil that spilled from a ruptured Mobil Oil Corp. pipeline near Magic Mountain early Friday. On the surface, the spill has been contained near the intersection of the Santa Clara River and Piru Creek where the oil flow is 12 feet wide in some places.

“It looks like they could reasonably get the heavy surface material cleaned up in a couple of days,” Gientke said.

But cleanup of the underground water supply could take months, he said. “The more volatile parts of the oil will go underground with the water. We’ll monitor it and we’ll correct it,” he said.

If high levels of the carcinogen benzene or other harmful chemicals are detected in the underground basins, United will pump the water out and dispose of it. The loss of water “is not going to help” the drought conditions in the county, he said.

United plans to release water in late March from Lake Piru down Piru Creek and into the Santa Clara River to spreading grounds that replenish the underground basins near Saticoy.

These basins provide all or part of the water supply for Fillmore, Santa Paula, Port Hueneme, Oxnard and Ventura.

Gientke predicts that the oil on the river will be cleaned up by the time the water is released. If any oil still remains, United will dig a channel in the riverbed to contain it, he said.

“The ribbon of water where the oil is is on the south side of the channel,” Gientke said. The water released from Lake Piru could flow past any remaining oil if a channel and a temporary dam are built, he said.

The spill is about eight miles long, said county Supervisor John K. Flynn, who was at the site Saturday morning. Flynn said six dams had been built with bulldozers, and the trapped oil was being sucked out from behind the berms.

State Department of Fish and Game officials said that the river is one of the last habitats for an endangered fish--the armored stickleback--and an important nesting ground for an endangered bird--the least Bell’s vireo.

“We are very concerned about the damage,” Capt. Roger Reese said.

The Berkeley-based International Bird Rescue Service is working with the fish and game department, catching oiled animals for cleanup and treatment. A muskrat, a heron, and about 18 other birds were trapped by Saturday afternoon, said Jan White, a veterinarian with the organization.

A deer and a coyote also were spotted in the spill, White said.

The animals are being treated at the site and sent to a shelter in Long Beach, she said.

Jay Holcomb of International Bird Rescue carried oil-soaked mallards and widgeons to the cleaning station. He said he found six dead birds Saturday, including one heron. At least four dead fish--none of them sticklebacks--were found.

Reese predicted that the count of dead and ill birds will probably increase dramatically as rescuers continue to find them in the vegetation along the stream.

Oil spills pose a serious threat to animals, White said. “Birds try to preen it off of themselves and so they swallow it.”

The oil causes the bird to vomit and become dehydrated and also causes hypothermia when sticky feathers are no longer able to repel water.

Animals soaked in the sludge can suffer from anemia and weight loss and can become ill if they drink from the contaminated stream, biologists said.

Mobil Oil Corp. officials said the spill was caused by an 18-inch-long crack in a 21-year-old section of the pipeline that extends from a pumping station east of the Golden State Freeway.

The pipeline was replaced and the pumping station was back in operation by midnight Friday, said Mobil spokesman Tim Salles.

On Saturday, along miles of the winding river, crews tended booms and filters that had been set up to trap and absorb the oil on the river’s surface.

Workers in yellow slickers stood almost knee-deep in the water, soaking up oil and residue with giant absorbent sheets of cotton and polyester.

Later, crews will remove the oil-contaminated dirt from the stream bed and hand wash plants and trees, Fish and Game Warden John Hernandez said.

The work will be “slow and very labor-intensive,” Salles said.

Salles said it was too soon to estimate how much the effort would cost or how much dirt had been contaminated.