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The Deepwater Horizon oil rig burns in 2010.

The Deepwater Horizon oil rig burns in 2010.

U.S. Coast Guard

After geoscientists joust, judge rules BP Gulf spill totaled 3.19 million barrels of oil

After a lengthy court proceeding featuring dueling testimony from numerous geoscientists, a federal judge has ruled that petroleum giant BP spilled 3.19 million barrels of oil into the Gulf of Mexico after the 2010 Deepwater Horizon drilling rig explosion. That is lower than the 4.2 million barrel number endorsed by U.S. government prosecutors—but higher than BP’s preferred estimate of 2.45 million barrels.

The ruling means that BP faces a maximum fine of $13.7 billion for violations of the Clean Water Act, although the company could pay less if the judge finds it took action to mitigate the spill. Under the RESTORE Act, a law passed by Congress in 2012, 80% of the fine will be dedicated to restoration, recovery, and research in the five Gulf Coast states most affected by the spill. And at least 5% of that money will be dedicated to scientific research in the Gulf.

“There is no way to know with precision how much oil discharged into the Gulf of Mexico,” District Court Judge Carl Barbier of the Eastern District of Louisiana in New Orleans wrote in a 44-page opinion released Thursday. “There was no meter counting off each barrel of oil as it exited the well. The experts used a variety of methods to estimate the cumulative discharge. None of these were perfect.”

During an earlier proceeding, Barbier heard from six experts who presented varying estimates of the size of the spill, ranging from as little as 2.4 million barrels to as many as 6 million barrels (see table below). “BP and the United States also presented competing theories of how the rate of discharge changed over the course of the spill,” Barbier wrote. “The evidence … was voluminous, dense, highly technical, and conflicting. … Both sides … mounted effective attacks on the other’s calculations.” They disputed, for instance, just how big the underground reservoir of oil was at the start of the spill, how much pressure it was under, and the permeability and “compressiblity” the surrounding rock layers.

Both BP and the government agreed that 810,000 barrels were captured from the damaged wellhead by a siphoning device before entering the Gulf. But prosecutors argued that 5 million barrels in all had streamed from the broken pipe, while BP argued it was just 3.26 million.

In the end, Barbier settled on 4 million barrels—meaning 3.19 million escaped during the 86-day ordeal, which began with an explosion on the Deepwater Horizon drilling rig on 20 April 2010, and ended on 15 July after engineers succeeded in capping the pipe.

The judge also ruled that BP “was not grossly negligent, reckless, willful, or wanton” in its oil spill planning, meaning it won’t face additional punitive damages.

But he did find that “[t]here is no dispute that BP lied about the amount of oil that flowed from the well” during the disaster. “The evidence shows that BP repeatedly told government officials that its best estimate for flow rate was 5,000 barrels of oil per day, while BP’s internal documents showed there was little basis for this estimate and actual flow rates were significantly higher.” The company later pled guilty to withholding information from Congress and government officials.

“Nevertheless, it has not been shown that BP’s misrepresentations regarding flow rate delayed the capping of the well or otherwise adversely affected source control efforts,” Barbier wrote.

The judge must now decide exactly how big BP’s fine will be in a proceeding that begins 20 January. The company faces the Clean Water Act’s maximum penalty of $4300 per barrel, because it has already been found to have acted with “gross negligence.” But the court is also required to consider other factors, BP's Geoff Morrell noted in a statement, including mitigation efforts, the economc impact of the penalty on the violator, and the seriousness of the violation. "BP believes that considering all the statutory penalty factors together weighs in favor of a penalty at the lower end of the statutory range," Morrell stated.

Clean Water Act fines are typically paid to the general treasury. In this case, however, Congress decided to divert 80% of the Deepwater Horizon fines to a special Gulf Coast Restoration Trust Fund. Under the RESTORE Act, 30% of the fund's money (plus interest) will go to restoration projects selected by a federal council, 2.5% to science programs administered by the National Oceanic and Atmospheric Admnistration, and 2.5% to grants sent to research centers of excellence established around the Gulf. The remaining 65% is dedicated to projects, including ecological restoration and economic development projects, selected by state governments and a federal council. 

BP’s Clean Water Act fines are not the only pot of restoration and research money created by the spill. Another firm, Transocean, has already paid a $1 billion Clean Water Act fine for its role in the spill. Both firms have paid $3.5 billion to a Gulf Environmental Benefit Fund administered by the National Fish and Wildlife Foundation. And an additional $500 million has gone to the National Academies to create a 30-year regional research program. Overall, BP estimates the spill has cost it $43 billion, including $28 billion for spill response, cleanup, and economic damage claims.

Here are the spill estimates, in millions of stock tank barrels of oil, provided to the court by six experts who testified:

  • Ronald Dykhuizen (Sandia National Laboratories, for the United States)—Best estimate: 5.0, range: 3.5 to 6.0

  • Stewart Griffiths (Sandia National Laboratories, for the United States)—Best estimate: 5.0, range: 4.3 to 5.5

  • Mohan Kelkar (University of Tulsa, for the United States)—Range: 4.5 to 5.4

  • Mehran Pooladi-Darvish (University of Calgary, for the United States)—Range: 5.0 to 5.3

  • Martin Blunt (Imperial College London, for BP)—Best estimate: 3.26, range 2.9 to 3.7

  • Alain Gringarten (Imperial College London, for BP)—Range: 2.4 to 3.0

*Update, 15 January, 10:11 p.m.: This story has been updated to include a statement from BP.