The barge Joe Griffin sails down a channel Wednesday on its way to the Gulf of Mexico carrying a chamber, right, that will be used to help contain oil leaking from the Deepwater Horizon oil drilling platform onto a ship in Port Fourchon, La.

New Orleans ? A rule change two years ago by the federal agency that regulates offshore oil rigs allowed BP to avoid filing a plan specifically for handling a major spill from an uncontrolled blowout at its Deepwater Horizon project — exactly the kind of disaster now unfolding in the Gulf of Mexico.

Oil rig operators generally are required to submit a detailed “blowout scenario.” But the federal Minerals Management Service issued a notice in 2008 that exempted some drilling projects in the Gulf under certain conditions.

BP met those conditions, according to MMS, and as a result, the oil company had no plan written specifically for the Deepwater Horizon project, an Associated Press review of government and industry documents found.

In a series of interviews, BP spokesman William Salvin insisted the company was nevertheless prepared to handle a blowout at that project because it had a detailed, 582-page regional plan for dealing with a catastrophic spill anywhere in the central Gulf.

“We have a plan that has sufficient detail in it to deal with a blowout,” Salvin said.

Still, the lack of a specific plan for the Deepwater Horizon project raises questions about whether the company could have been better prepared to deal with the oil leak, which is still spewing out of control at a rate estimated at more than 200,000 gallons a day.

Oil and oil sheen are seen Wednesday in the waters of Chandeleur Sound, La.

‘MMS can’t change the law’

MMS, which is part of the Interior Department, has long been criticized as too cozy with the industry it regulates.

Robert Wiygul, an Ocean Springs, Miss., environmental lawyer, said the lack of a blowout scenario “is kind of an outrageous omission, because you’re drilling in extremely deep waters, where by definition you’re looking for very large reservoirs to justify the cost.”

“If the MMS was allowing companies to drill in this ultra-deep situation without a blowout scenario, then it seems clear they weren’t doing the job they were tasked with,” he said.

The disaster was set in motion when the offshore platform 50 miles out in the Gulf of Mexico exploded April 20 and sank days later in 5,000 feet of water. Eleven workers were killed in the accident.

AP pressed MMS for an explanation of why the rules were changed, but no official would speak on the record. However, one MMS official who spoke on condition of anonymity because the official wasn’t authorized to discuss the matter said the rules were changed because some elements were impractical for some deepwater drilling projects in the Gulf.

But Wiygul said: “The MMS can’t change the law just by telling people that they don’t have to comply with it. I think it really indicates that somebody at MMS was asleep at the switch on this.”

Speaking with reporters after touring a boom operation in Gulf Shores, Ala., Interior Secretary Ken Salazar said that he understood that BP was required to file plans for coping with a blowout at the well that failed.

“My understanding is that everything was in its proper place,” Salazar said.

However, an AP review of BP’s regional oil-spill plan found that it failed to specifically address all of the points required by the MMS in a blowout scenario.

Blowout scenario

The blowout scenario rules, contained in the Code of Federal Regulations, require rig operators to estimate how much oil could flow from the well per day and the total amount that could leak from a single incident.

They also require such things as an explanation of how a spill would be stopped, the methods that would be used, how long it would take to stop the leak, how long it would take to drill a relief well, and the potential for a well to stop leaking on its own.

The MMS rule change, made in April 2008, says that Gulf rig operators are required to file a blowout scenario only if one of five conditions applies.

For example, an operator must provide a blowout scenario when it proposes to install a “surface facility” in water deeper than 1,312 feet. While Deepwater Horizon was operating almost 5,000 feet below the surface, Salvin said the project did not meet the definition of a surface facility. The MMS official agreed.

“The production platform is what’s considered a surface facility,” Salvin said. “This was an exploratory well, not a production well.”

In its 2009 exploration plan, BP strongly discounted the possibility of a catastrophic accident. Similary, Shell’s environmental impact analysis for its Beaufort Sea drilling plan asserts that the possibility of a “large liquid hydrocarbon spill … is regarded as too remote and speculative to be considered a reasonably foreseeable impacting event.”