2010-07-20 09:34

BP and the Coast Guard learned that lesson the hard way after they initially said no oil was coming from the site of the Deepwater Horizon rig after it exploded April 20, killing 11 workers. Even after it became clear there was a leak, the company and its federal overseers drastically underestimated its size for weeks.

Robert Carney, a Louisiana State University expert on biological oceanography, said the seepage is far enough away from the well that it could be occurring naturally.

"You have little bubbles rising up from the bottom frequently; that's the methane gas" he said. "Oil would be a little black dot, more difficult to see. But both escape into the water regularly."

One other possibility: There are around 27,000 abandoned wells in the Gulf. One of them is within two miles (three kilometers) of BP's blowout, and there is a second well in the area that is not in production.

While officials gave no indication that the seepage was from another well, they're not checked for leaks, an Associated Press investigation showed this month.

Work on a permanent plug is moving steadily, with crews drilling into the side of the ruptured well from deep underground. By next week, they could start blasting in mud and cement to block off the well for good. Killing the well deep underground works more reliably than bottling it up with a cap.

Somewhere between 94 million and 184 million gallons (356 million and 697 million liters) have gushed into the Gulf over the past three months in one of America's worst environmental crises.

BP said the cost of dealing with the spill has now reached nearly $4 billion. The company said it has made payments totaling $207 million to settle claims for damages. Almost 116,000 claims have been submitted and more than 67,500 payments have been made. BP stock was down slightly Monday.