A revised environmental review of a contested Arctic oil lease makes drilling in the area far more likely, a development that has infuriated environmentalists.
The federal Bureau of Ocean Energy Management released the new environmental assessment of drilling leases on Thursday, upping the projected oil yield but saying little otherwise about the potential environmental impact.
The revised report was a particularly bitter disappointment for environmentalists, who had just celebrated the Obama administration's decision in January to put parts of the Beaufort and Chukchi seas off-limits from future oil and gas leasing.
The contested oil lease held by Royal Dutch Shell in the Chukchi Sea has been tied up in litigation since the government put 30 million acres up for sale in 2008.
Shell bought a piece, and an arm of the Interior Department estimated the company would extract 1 billion barrels of oil.
Environmentalists argued that the figure was too low, and sued.
In January 2013, they won. The U.S. 9th Circuit Court of Appeals in San Francisco ruled that the Interior Department did not properly evaluate the impact of oil development in the Chukchi Sea.
The environmental review released Thursday did not provide environmentalists with the victory they hoped for two years ago. It pegged extraction at 4.3 billion barrels of oil and 2.2 trillion cubic feet of natural gas -- and left the Shell lease intact.
Michael LeVine, Pacific senior counsel for Oceana, a plaintiff, said: "Despite its failures, Shell continues to push expanded plans for exploration drilling, and the government appears willing to bend over backwards to make it possible by rushing its analysis and refusing to consider foregoing the leases owned by Shell and other companies."
Shell did not respond to a call for comment.
In the new environmental review, Bureau of Ocean Energy Management forecast 260 small oil spills of less than 1,000 barrels each during the 44-year production phase of the lease.
It also found a 75% chance that one or more spills of more than 1,000 barrels during the entire 77-year lease.
Oceana said in a statement: "Such a spill would be nearly impossible to contain and clean up in the remote environment ... and could have significant impacts to the subsistence resources and other wildlife that depend on the Chukchi Sea."