WASHINGTON — Government scientists Thursday said as many as 40,000 barrels of oil have been flowing daily from the blown-out BP well, doubling earlier estimates and greatly expanding the scope of what is already the largest spill in U.S. history.
The new figures could mean 42 million to 84 million gallons of oil have leaked into the Gulf since the Deepwater Horizon rig exploded on the night of April 20 -- nearly four times the size of the 1989 Exxon Valdez spill.
The flow estimates were released by Marcia McNutt, director of the U.S. Geological Survey, and do not count any increases that may have occurred since the cutting of the well's riser pipe, a step that was expected to boost the flow.
Teams using a variety of technologies are trying to calculate how much the riser cut has increased the well release, but they will not have that information for several more days. "It's a challenging scientific issue," McNutt said.
The new flow numbers are the latest in a series of estimates that have steadily grown as scientists analyzed live video feeds. The earliest figure, 1,000 barrels, was replaced by 5,000 barrels. A government-appointed scientific team then pegged the flow at 12,000 to 19,000 barrels.
That same group has now concluded that "given the limited data available and the small amount of time to process that data, the best estimate for the average flow rate for the leakage ... is between 25,000 to 30,000 barrels per day, but could be as low as 20,000 barrels per day or as high as 40,000 barrels per day," McNutt said in a release.
In a sign of the difficulty of estimating the flow, one team believes that the upper range could be as high as 50,000 barrels. There are 42 gallons in a barrel of oil.
The new flow numbers confirm the suspicions of engineers who have watched live feeds of the billowing flows from the well over the last few weeks, and who questioned the government's and BP's earlier estimates. After initial estimates of 1,000 and then 5,000 barrels, a government-appointed scientific team had pegged the flow at 12,000 to 19,000 barrels and possibly as high as 25,000.
BP has said it will be unable to plug the well before August, when relief wells will be completed. But a containment cap installed on the well last week is capturing about 15,000 barrels, or 630,000 gallons, a day and pumping it to a ship at the surface. Officials predict that by next week they will be able to collect or burn off nearly twice that amount.