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 U.S. 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 into the Gulf. BP has urged Barbier to use an estimate of 2.45 million barrels, or nearly 103 million gallons, in calculating any Clean Water Act penalties. Both sides agree that 810,000 barrels, or 34 million gallons, 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.
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 different estimates.
Justice Department attorney Steven O'Rourke accused BP experts of "cherry-picking" data and disregarding information collected during its spill response efforts.
"The evidence will show that those theories are not valid," said O'Rourke, who noted that the government's estimate would make BP's oil spill roughly 16 times larger than the 1989 Exxon Valdez spill in Alaska, which dumped 11 million gallons of oil into the Prince William Sound.
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 of the well.
"BP will present information and opinions based on known data—known data before the spill and known data after the spill," he said. "It's an industry standard approach to resolving or solving a problem like this."
Government experts estimate that oil started flowing out of the Macondo well at a rate of roughly 62,000 barrels per day but dropped to a rate of 53,000 barrels per day when BP used a capping stack equipped with a pressure gauge to seal the well. O'Rourke said four government experts employed four different methods and reached strikingly similar estimates.
"Why four different methods? Because this is an unusual problem," he said.
Conversely, BP's experts concluded that flow rates increased over time, due in part to the erosion of steel rams on the rig's blowout preventer. Brock said the government based its estimate on the flawed theory that erosion of cement, drill pipe and other obstructions in the well ended within hours of the blowout.
"The government has not accounted for events within the well on a day-by-day basis," Brock said.
Brock showed Barbier excerpts of email exchanges between government officials in an effort to show that they were under pressure from President Barack Obama's administration early in the spill to quickly estimate its size. One of the officials suggested they could determine the flow rate over time by "backtracking" from a current estimate.
"That is the flaw in the methodology they've employed here," Brock said.
O'Rourke urged the judge to disregard BP's efforts to portray government scientists as "political hacks."
"There was no conspiracy. There was no government agenda," he said. "They were there to get the right answers and to help."
The Deepwater Horizon drilling rig was working at the site of BP's Macondo well off the Louisiana coast when the blowout triggered an explosion that killed 11 workers. The rig sank less than two days later to the bottom, about a mile below the Gulf surface.
For the trial's first phase, which ended in April, Barbier heard eight weeks of testimony about the causes of the April 2010 well blowout.