Majority of spilled oil in Gulf of Mexico unaccounted for in government data

It has been 100 days since an explosion tore apart the Deepwater Horizon drilling platform. That event unleashed a gush of oil into the Gulf of Mexico, creating an environmental catastrophe and forever altering life along those shores.
By David A. Fahrenthold and Leslie Tamura
Washington Post Staff Writer
Thursday, July 29, 2010

Was Tony Hayward right, after all?

Back in May, BP's chief executive told a British newspaper that "the Gulf of Mexico is a very big ocean," and the vast amounts of oil and chemical dispersants dumped into it were small by comparison. After he said that, BP's well leaked for two more months. Hayward's upbeat assessment was cast as one of many gaffes committed on his way to resignation.

Now, 14 days after the well was closed and 100 days after the blowout, U.S. government scientists are working on calculations that could shed some light on Hayward's analysis (even if they can't shed light on why he said it). They are trying to figure out where all the oil went.

Up to 4 million barrels (167 million gallons), the vast majority of the spill, remains unaccounted for in government statistics. Some of it has, most likely, been cleaned up by nature. Other amounts may be gone from the water, but they could have taken on a second life as contaminants in the air, or in landfills around the Gulf Coast.

And some oil is still out there -- probably mixed with chemical dispersants. Some scientists have described it floating in underwater clouds, which one compared to a toxic fog.

"That stuff's somewhere," said James H. Cowan Jr., a professor at Louisiana State University. His research has shown concentrations of oil still floating miles from the wellhead. "It's going to be with us for a while. I'm worried about some habitats being exposed chronically to low concentrations of toxins. . . . If the water's contaminated, the animals are going to be contaminated."

'The truth is in the middle'

By July 15, when the mile-deep BP well was capped, it had leaked out enough oil to fill the Pentagon more than 10 feet high. The gulf's total volume is about 880 million times the size of the Pentagon -- although the oil's effects were concentrated in one corner of it.

On Wednesday, National Oceanic and Atmospheric Administration chief Jane Lubchenco said the oil is now much less visible on the surface and present only in microscopic, dilute droplets further down. She said that was a sign that the gulf ecosystem is resilient and processing the hydrocarbons.

But she said that "doesn't mean the situation is benign, because it is not."

"There's so much noise out there now saying the gulf is dead or the gulf will come back easily," Lubchenco said. "The truth is in the middle."

The government's accounting of what became of all the oil will be key to making this final judgment. Officials did not provide a date when that accounting would be ready. For now, government figures allow only a rudimentary estimate of the oil that might still be unaccounted for.

Relying on the latest estimate of the leak's total volume -- 60,000 barrels (2.5 million gallons) per day, at most -- then 5.2 million barrels may have escaped over 86 days. Of that, about 1.2 million barrels were either siphoned, burned or skimmed.

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