By Steven Mufson
Washington Post Staff Writer
Friday, December 3, 2010; 10:17 PM
BP lawyers have said that government estimates of the size of the Gulf of Mexico oil spill are too big, perhaps by as much as 20 to 50 percent, signaling a dispute that will determine how many billions of dollars of fines BP will have to pay under the Clean Water Act.
The BP attorneys made their comments in an Oct. 21 meeting with staff members of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, Priya Aiyar, one of the commission lawyers, revealed at a hearing Friday.
The oil giant, in a paper submitted to the presidential oil spill commission, also took issue with one of its draft reports. BP said that the assertion that "a consensus is emerging that roughly 5 million barrels of oil were released by the Macondo well is both premature and inaccurate."
BP said that the estimates by the Energy Department and an inter-agency group "appear biased toward the maximum amount of oil that could have been discharged, rather than the amount of oil most likely to have been discharged."
Penalties for spilling oil start at $1,100 a barrel and can rise to $4,300 if negligence is proved.
Rep. Edward J. Markey (D-Mass.), a sharp critic of the company, said in a letter Friday to BP chief executive Bob Dudley that "BP's new claim that the spill is much smaller than previously thought flies in the face of multiple lines of evidence, and raises questions whether this is a scientific finding, or a litigious position."
The oil company said that government and other academic experts did not properly take into account factors such as temperature differences, the amount of natural gas mixed in, and partial blockages from bent pipes, partial closure of the blowout preventer and from debris.
The company said that the flow rate had increased over time as impediments to the oil were cut away or eroded by the tremendous force of the oil and gas.
BP said that it was still too soon to reach a final conclusion about how much oil leaked from the Macondo well after a blowout sank the Deepwater Horizon drilling rig, killing 11 people. While the government's group left a margin of error of 10 percent, BP said it "believes the range of uncertainty is substantially greater."
The government has estimated that 62,000 barrels a day initially gushed from the Macondo well after the blowout, later dropping to 53,000 barrels as the reservoir was depleted. But the flow rate has been a subject of dispute from the early days of the spill, when the government estimated that 5,000 barrels a day were leaking into the gulf. Later, BP was collecting 25,000 barrels a day, and oil was still gushing into the gulf.