In May 2010 , McNutt headed the Flow Rate Technical Group which attempted to measure the Deepwater Horizon oil spill in the Gulf of Mexico . Preliminary reports from the group said that the rate of the oil spill was at least twice and possibly up to five times as much as previously acknowledged . Subsequent estimates , based on six independent methodologies , were four times the 1989 Exxon Valdez oil spill . A refined estimate based on new pressure readings , data , and analysis , released by the United States Secretary of Energy Steven Chu and McNutt in August , said that 4.9 million barrels ( with uncertainty of plus or minus approximately 10 percent ) of oil had leaked from the well until it was capped on July 15 . The disaster was the largest ever accidental spill of oil into marine waters
Deepwater Horizon oil spill
Deepwater Horizon oil spill
Marcia McNutt