MIAMI — BP failed Saturday to thread a mile-long tube into the broken pipe spewing oil into the Gulf of Mexico, but officials said efforts to break up the oil underwater seemed to be working.
The Environmental Protection Agency gave BP the go-ahead on Saturday to use dispersants, chemicals that break the oil into small droplets and keep it from rising to the surface.
"It appears that the application of the subsea dispersant is actually working," BP Chief Operating Officer Doug Suttles said. "The oil in the vicinity of the well is diminished from previous observations."
At least 210,000 gallons of oil have been gushing into the Gulf each day since the Deepwater Horizon exploded on April 20, and some independent scientists think the leak may be 10 times that bad.
Late Friday, technicians tried to stop the leak by guiding a six-inch-wide tube with a rubber stopper into the broken undersea pipe. But they had trouble connecting the tube to an oil tanker on the surface, and had to return the contraption to the surface.
"The challenge here is working with 5,000 feet of water," Suttles said.
BP hasn't given up on the tube strategy yet. Suttles said they will try it again late Saturday. If that fails, the next step will be to place a steel-and-concrete dome called a "top hat'' over the leak and attempt to siphon the oil to a ship on the surface.
Officials are also tossing around another potential solution called a ''junk shot." That entails shooting golf balls, shredded tires, knotted pieces of rope and other types of debris into the blowout preventer to clog the leak.
"We are resolute in our efforts to do whatever we can to bring this problem under control," Interior Secretary Ken Salazar said.
Earlier in the month, crews tried to contain the spill by placing a 78-ton containment dome over the leak. But the effort failed when icy crystals formed inside the dome, clogging the opening through which the oil was to pass and making the dome too buoyant to form a tight seal on the seafloor.
Additionally, BP and the U.S. Coast Guard continued efforts to contain the oil that had already spilled into the water, Coast Guard Rear Admiral Mary Landry said. Vessels skimmed oil from the surface, and the Coast Guard staged controlled burns.
Landry said the Coast Guard would be "analyzing and monitoring'' the underwater dispersants.
"We have a very good handle on the oil we're dealing with," she said. ''We're tracking it constantly."
Environmentalists -- and some leaders in the fishing and oil spill cleanup industries -- have raised concerns about using chemical dispersants.
"Cosmetically, it makes it seem that the oil has gone away," said Tom Manton, the retired president and CEO of the International Oil Spill Control Corporation. "But the oil doesn't go away. It ends up in small drops, either on the beach or on the seabed. . . In many cases, the dispersants are more polluting to the water than the actual oil is."
The EPA and Coast Guard, however, say that the dispersants are "generally less harmful'' than oil and will biodegrade in a shorter time span.
EPA Administrator Lisa Jackson has said they could "lessen the overall impact of the spill."
Along the Gulf Coast, wary residents and tourists waited for tarballs and ribbons of emulsified oil to wash ashore.
So far, Landry said, "we've had minimal impact to the shoreline. We've had minimal impact to the wildlife and beaches."
Prices of shrimp and oysters around the Gulf Coast are rising as restaurants and seafood retailers experience shorter supply and higher costs due to the oil spill.
"Things are getting harder," said Artie Desporte, owner of Desporte & Sons Seafood Market and Deli in Biloxi.
Prices for shrimp and oysters fluctuate daily, Desporte said. Shrimp has gone up 75 cents to $1 per pound, and oysters have gone up $2 per pound, he said.
Also on Saturday, BP officials met with fishermen in D'Iberville, Miss., who had been affected by the oil spill. They discussed short-term and long-term financial assistance, job opportunities and legal rights.
Meanwhile, Salazar and Secretary of Homeland Security Janet Napolitano released a letter they sent jointly to BP CEO Anthony Hayward putting him on notice that they expect BP to honor its public vows to take responsibility for full compensation of all who suffer economic damage from the spill. They emphasized that they expect BP "will not in any way seek to rely on the potential $75 million statutory cap" and refuse to pay more if full compensation requires more.
BP estimates that it has already spent more than $450 million to mitigate the impact of the oil spill. Company leaders have pledged to cover the entire cost of the clean-up, despite the federal government's $75 million liability cap.
In a segment for "60 Minutes" scheduled to air Sunday, survivor Michael Williams, chief electronics technician aboard the Deepwater Horizon, said after the April 20 blowout, natural gas got sucked into the rig's engines, causing them to run out of control and explode.
"I'm hearing hissing. Engines are over-revving and then all of a sudden, all the lights in my shop just started getting brighter and brighter and brighter and I knew something bad was getting ready to happen," Williams said in a partial transcript released by CBS News.
Williams jumped about 100 feet into the Gulf from the burning rig, suffering broken ribs.
"The well kicked, the safety systems failed, and men lost their lives. I don't know how else to say it," Williams said. "All the things that they told us could never happen, happened. You know, on a daily basis, we were told, 'We're going to send you home better than the day you got here. It wasn't true that day.'"
(McGrory reports for The Miami Herald. Biloxi Sun reporters Donna Melton and Nicole Dow and Charlotte Observer reporter Mark Washburn contributed to this report.)
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