NEW ORLEANS — For weeks after BP’s massive 2010 oil spill in the Gulf of Mexico, people across the globe were captivated by a live video feed from underwater cameras that showed the company’s blown-out well belching plumes of black crude into the water.
On Monday, more than three years later, clips from the spill cam were projected on a screen in a New Orleans courtroom while lawyers for BP and the federal government quarreled over how much oil gushed out of BP’s Macondo well during the 87-day crisis. The images helped some of the scientists calculate how much oil polluted the gulf.
Determining how much oil spilled is a multibillion-dollar question for US District Judge Carl Barbier, who is presiding over the trial involving the deadly Deepwater Horizon rig explosion and the nation’s worst offshore oil spill. The judge ultimately could decide how much more money BP owes for its role in the disaster.
Government experts estimate 4.2 million barrels, or 176 million gallons, spilled. BP has urged Barbier to use an estimate of 2.45 million barrels, or 103 million gallons, in calculating any penalties. Both sides agree that 810,000 barrels escaped the well but were captured before the crude could pollute the gulf.
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. But penalties can be assessed at amounts lower than those caps.
Using the government’s figures, a maximum penalty if the company is found grossly negligent could total $18 billion. Using the company’s figures, that maximum penalty would be around $10.5 billion.
During opening statements Monday for the latest phase of the trial, lawyers for BP and the government outlined conflicting scientific theories to explain their estimates.
Justice Department attorney Steven O’Rourke accused BP experts of ‘‘cherry-picking’’ data and disregarding information collected during its response efforts.
‘‘The evidence will show that those theories are not valid,’’ said O’Rourke, who noted the government’s estimate would make BP’s spill roughly 16 times larger than the 1989 Exxon Valdez spill in Alaska.
BP lawyer Mike Brock said the government’s estimates don’t account for the uncertainty of flow conditions between the April 20 blowout and the July 15 capping.
‘‘BP will present information and opinions based on known data — known data before the spill and known data after the spill,’’ he said.
The Deepwater Horizon drilling rig was working at BP’s Macondo well when the blowout triggered an explosion that killed 11 workers. The rig sank two days later. For the trial’s first phase, which ended in April, Barbier heard eight weeks of testimony about the causes of the well blowout.