NEW ORLEANS (AP) -- The federal judge presiding over a trial arising from the nation's worst offshore oil spill said Thursday that it could be difficult to determine how much crude spewed into the Gulf of Mexico from BP's blown-out well in 2010.
"That is not an easy task," U.S. District Judge Carl Barbier noted during a hearing. "There was no meter on that well."
Barbier heard testimony earlier this year for the trial's first phase about the possible causes of the deadly disaster. Determining how much oil spilled into the Gulf is a topic for the trial's second phase, set to begin Sept. 16.
London-based BP PLC and the federal government have very different estimates on the size of the spill. The federal government estimates more than 200 million gallons spewed from the well, including more than 34 million gallons that were collected.
BP expert Martin Blunt, a professor of petroleum engineering at Imperial College in London, claims the government overestimated the size of the spill by 26 to 42 percent. Justice Department lawyers attached a copy of Blunt's report to a court filing Thursday.
Under the Clean Water Act, a polluter can be forced to pay a maximum of either $1,100 or $4,300 per barrel of spilled oil. The higher maximum applies if the company is found grossly negligent, as the government argues BP should be. Barbier noted during the hearing that penalties can be assessed at amounts lower than those caps.
Clean Water Act penalties are the subject for the trial's third phase, which hasn't been scheduled yet.
The April 20, 2010, blowout triggered an explosion that killed 11 workers on the Deepwater Horizon drilling rig. BP finally stopped the flow of oil after 86 days.
Earlier this week, BP placed a full-page advertisement in three of America's largest newspapers as the company mounted an aggressive campaign to challenge what could be billions of dollars in settlement payouts to businesses following the spill.