Oil spill alarm rises after containment dome setback

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BP Plc engineers on Sunday desperately explored options to control oil gushing from a ruptured Gulf of Mexico well after a setback with a huge containment dome fueled fears of a prolonged and growing environmental disaster.

BP was considering its next move after a buildup of crystallized gas in the dome forced engineers to suspend efforts to place the four-story chamber over the rupture, the company's best short-term solution to containing the spill.

The mammoth dome was set aside on the sea floor while BP seeks solutions -- a process it said on Saturday could take two days.

"People are working around the clock at BP headquarters," US Coast Guard Admiral Thad Allen told National Public Radio on Sunday. But conducting operations at depths of one mile (1.6 km) below the surface was complicating the challenge, he said.

"We're actually dealing with a source that doesn't have human access," Allen said.

At least 5,000 barrels (210,000 gallons/795,000 litres) of oil a day are gushing unchecked into the Gulf since the Deepwater Horizon rig exploded on April 20, killing 11 crew members and rupturing the well.

On Dauphin Island, Alabama, a barrier island and beach resort full of weekend swimmers and beachcombers, sunbathers found tar balls and tar beads washing up along a half-mile stretch of the white-sand beach. Experts were testing the tar to determine if it came from the huge Gulf spill.

The spill, which could become the worst in U.S. history, threatens economic and ecological disaster on Gulf Coast tourist beaches, wildlife refuges and fishing grounds. It has forced President Barack Obama to rethink plans to open more waters to drilling.

BP Chief Executive Tony Hayward told London's Sunday Telegraph newspaper it could be weeks or months before the spill is brought under control. He said the company could spend $10 million a day on clean-up efforts.

BP engineers were exploring ways to overcome the containment dome's problem with gas hydrates -- essentially slushy methane gas that would block the oil from being siphoned out of the top of the box.

Shooting debris into blowout preventer

Possible solutions could include heating the area or adding methanol to break up the hydrates, Chief Operating Officer Doug Suttles said.

If the problem is solved, engineers would attach a pipe to the dome and pump the captured oil to a surface tanker. The goal was to capture about 85 percent of the leaking crude.

"Let's hope and pray that this dome works," Republican Senator Richard Shelby of Alabama told CNN. "If it doesn't work, I don't know where we go."

BP may try to plug the damaged blowout preventer on the well by pumping debris into it at high pressure, a technique called a "junk shot," or attaching a new preventer on top of it.

"They are actually going to take a bunch of debris -- some shredded up tires, golf balls and things like that -- and under very high pressure shoot it into the preventer itself and see if they can clog it up to stop the leak," Allen told CBS's "Face the Nation."

BP also is drilling a relief well to halt the leak but that could take three months.

Hundreds of boats deployed protective booms and used dispersants to break up the oil again on Sunday. Crews have laid more than 900,000 feet (270,000 metres) of boom and spread 290,000 gallons (1.1 million litres) of chemical dispersant in fighting the growing slick.

Residents of Alabama's Dauphin Island, although used to rough weather sweeping in from the Gulf, did not conceal their alarm over the threat of the slick coming ashore.

"It is the price you pay for living on the coast. I am just worried about it getting in the Gulf Stream and carried up the coast," said Dolores Dorr.