Reuters – Cleanup crews fanned out across an oil-fouled California beach on Wednesday to scoop up gobs of petroleum spewed from a burst pipeline in what may be the biggest oil spill to hit the pristine but energy-rich Santa Barbara coastline in 46 years.

As much as 2,500 barrels (105,000 gallons) of crude oil was released in Tuesday's rupture, according to a "worst-case scenario" presented by the pipeline company, five times more than was initially estimated.

Plains All American Pipeline said it calculated that up to a fifth of the total spill had reached the ocean.

The 24-inch-wide pipeline, which runs underground parallel to a coastal highway west of Santa Barbara, inexplicably burst late on Tuesday morning, belching crude oil down a canyon, under a culvert and onto Refugio State Beach before it flowed into the Pacific, U.S. Coast Guard officials said.

Plains Chief Executive Officer Greg Armstrong told an evening news conference that pipeline pressure irregularities were detected by control-room operators at about 11 a.m. on Tuesday, and the line was shut off in about 30 minutes.

Company spokesman Brad Leone acknowledged that residual oil in the pipeline continued to drain for some period after the shutdown. The spill was discovered about an hour later, when people in the area noticed a petrochemical odor and alerted authorities, officials said.

By Wednesday, a 4-mile stretch of beach was blackened, and an oil slick spanned more than 9 miles of the ocean, the Coast Guard said.

It appeared to surpass the size of an offshore rupture in 1997 that dumped up to 1,000 barrels of crude into the Santa Barbara Channel, about 125 miles northwest of Los Angeles, said Kevin Drude, deputy energy director of the county's Planning and Development Department.

That spill, and Tuesday's accident, pale in comparison with the estimated 80,000 to 100,000 barrels of oil that gushed into the channel from an offshore oil-well blowout in 1969 and stands as the largest oil spill ever in California waters.

Drude and officials from conservation groups said Tuesday's oil spill - if Plains' estimates hold up - likely ranks as the largest along the Southern California coast since the 1969 Santa Barbara blowout, which killed thousands of sea birds and other wildlife and helped spark the modern U.S. environmental movement.

SENSITIVE NESTING SITES

Janet Wolf, who chairs the Santa Barbara County Board of Supervisors, called the latest spill "a disaster" and "a worst-nightmare scenario."

Governor Jerry Brown issued an emergency proclamation to speed needed cleanup resources to the scene, saying, "We will do everything necessary to protect California's coastline."

The spill zone lies at the edge of a national marine sanctuary and state-designated underwater preserve that is home to 25 marine mammal species and 60 species of sea birds. But the Santa Barbara Channel and surrounding waters are also dotted with nearly two dozen oil platforms and hundreds of wells.

Wildlife teams were dispatched to rescue any birds, marine mammals and other animals injured by the spill. Authorities said the extent of wildlife damage was not immediately known, but photos showed oil-covered pelicans and other sea life washed ashore.

Crews focused on three especially sensitive nesting areas for shore birds, including snowy plovers and least terns, a state Fish and Wildlife Department spokeswoman said.

Refugio State Beach and El Capitan State Beach, both popular seaside camping destinations, were to remain closed to the public through the Memorial Day holiday weekend, officials said. The area was also closed to fishing and shellfish harvesting.

Some 300 cleanup workers on the beach were scooping up globs of oil from the sand, raking tar balls and disposing of the material in plastic bags.

Crews will also scrub soiled rocks, hose down contaminated areas and skim oil left behind, Coast Guard Captain Jennifer Williams told reporters in nearby Goleta.

Nine cleanup vessels plied the ocean, six to corral the slick with booms and three others skimming oil from the surface.

The pipeline that burst on Tuesday typically carries about 1,200 barrels of oil an hour from an Exxon Mobil processing facility to a distribution hub in Bakersfield hundreds of miles away, company and county officials said.

The company said an internal inspection of the pipeline was conducted a few weeks ago but results had not yet come back.