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.
(From SCIENCEINSIDER / by 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.