The “vast majority” of crude from BP Plc’s damaged Gulf of Mexico well is gone and the rest is being broken down by waves and bacteria, reducing the threat of further pollution from the largest maritime oil spill, White House energy adviser Carol Browner said.
“The vast majority of the oil has been contained, it’s been burned, it’s been cleaned,” Browner said on CBS’s “Early Show” today. The remaining oil “will weather, it will break down naturally. Mother Nature will do her part.”
An estimated 4.9 million barrels of oil leaked from BP’s Macondo well between April 20 and July 15, according to government scientists. BP was able to capture about 800,000 barrels of crude from the well before it entered the Gulf. The leak began after the Deepwater Horizon drilling rig exploded off the coast of Louisiana, killing 11 workers.
“I find it very hard to believe, impossible actually, that they have three-quarters of the oil accounted for,” Samantha Joye, a professor of marine sciences at the University of Georgia in Athens, said today in an e-mail.
Joye was among scientists who discovered plumes of oil under the Gulf’s surface and has been continuing to survey and analyze the results of water samples.
Browner said the government will “continue to be vigilant” on cleaning oil that washes ashore in the region. BP’s successful effort to control pressure in the well yesterday by forcing drilling mud into it is “good news,” she said.
About three-quarters of the 4.1 million barrels spilled directly into the Gulf by BP’s well has evaporated, dispersed, been captured or otherwise removed from the environment, The New York Times reported, citing a government study.
Jen Austin, a spokeswoman for the U.S. National Oceanic and Atmospheric Administration, said the agency would issue the report by 11 a.m. New York time.
“When they say that there’s 25 percent of the oil remaining, that is almost five times the Exxon Valdez,” which spilled crude into Alaska’s Prince William Sound in 1989, said Ian MacDonald, a professor of oceanography at Florida State University in Tallahassee.
Though there may be no oil washing onto beaches, tar balls can be found six to 10 inches (15 to 25 centimeters) below the surface, he said.
“An enormous amount of the oil is now buried and we know from previous spills that this buried material can persist for decades,” MacDonald said. “And that oil does have an effect on the behavior and health of the animals.”
BP, based in London, reported a “significant milestone” today toward plugging the well permanently, as engineers carried out the “static kill” to inject drilling mud into it over a period of eight hours yesterday.
The company said it will consult with National Incident Commander Thad Allen on whether to pump more mud and whether to attempt to plug the well from the top with cement.
BP rose 4.35 pence, or 1 percent, to 420 pence at 2:51 p.m. in London trading. The cost of insuring BP’s debt for a year with credit-default swaps dropped below five-year premiums today for the first time in two months on speculation the bid to close the well will succeed.
Browner said completion of a relief well, begun May 2 and now within about 100 feet (30.5 meters) of intercepting the damaged bore, is necessary to permanently plug the well.
The relief well will be done in 10 to 14 days, she said.