WASHINGTON - Now that BP has shut off oil flowing into the Gulf of Mexico from its broken well for the first time in 12 weeks, the company faces a Herculean task of cleaning up the region's oily mess.
While BP has hired thousands of people to boom, skim and burn large amounts of crude, the bulk of an estimated 200 million gallons of oil that spewed into the water is actually beyond human reach. As a result, the ultimate cleanup will be left to nature and to colonies of oil-chomping microbes.
Two factors contributed. First the crude oil gushed deep beneath the surface and was moved in unknown directions across the Gulf by uncharted currents. Then BP used dispersants to break the oil into tiny bits. Capturing most of the spill is now all but impossible to do.
Even the consequences are hard to gauge. Scientists can't predict how quickly the microbes will work or how much damage the oil will do first. However, livelihoods already have been wrecked and wildlife is endangered.
"I think the bottom line is that once the oil gets into the water column -- not just the surface -- the genie is out of the bottle [and] that we do not have any effective ways to get the genie back into the bottle," said Robert Bea, a University of California engineering professor and an expert on offshore drilling.
Bea worked for Shell Oil on the Santa Barbara oil spill in 1969 and the Bay Marchand, La., spill in 1970 and for the Mexican oil company Pemex on the huge Ixtoc spill in 1979. In the years since those spills, the technology of cleanup hasn't changed, he said.
The booms are better, and new materials absorb more oil than the straw that once was used, he said. For the most part, however, the only ways to get rid of the oil are old ones -- burning it, mopping it up and letting nature break it down.
Bea said that two of the newer approaches used by BP to combat the blowout didn't work very well. The unprecedented use of chemical dispersants -- more than The Coast Guard says nearly 33 million gallons of oily water in all have been recovered; as much as 15 percent of that -- or nearly 5 million gallons -- is oil. They estimate that nearly 11 million gallons of oil have been burned. In addition, BP says it has flared or recovered about 34.7 million gallons.
That's more than 50 million gallons in all pulled out of the Gulf -- or about a quarter of the amount spilled into it. The National Oceanic and Atmospheric Administration, however, said its analysis found that about a third of the oil had been recovered or cleaned.
Terry Hazen, a scientist at the Department of Energy's Lawrence Berkeley National Laboratory, has been conducting research in the Gulf for the past six weeks studying how the microbes are degrading the oil. He said as long as the naturally occurring microbes have enough nutrients, they'd work quickly in the 84-degree water at the surface. He estimates that the oil could be gone in months, or possibly years. Oil can be toxic to marine life, "but it also can completely biodegrade," Hazen said. "We're going to have to wait and see. I suspect that at the surface ... it will degrade fairly rapidly."
Fish and Wildlife Service sea turtle expert Debby Crouse wasn't so sure. The damaging oil, she said, is "going to be there for a long time."
