BP PLC has not yet concurred with the official government estimate of the amount of oil released during its 87-day Gulf of Mexico leak, according to correspondence released today by a senior House Democrat investigating the company's role in the spill.

In response to an Aug. 11 letter from Rep. Ed Markey (D-Mass.), chairman of the House Energy and Commerce Committee's environment panel, a lawyer representing BP indicated that the company was still weighing whether it would align with estimates released earlier this month by federal scientists that pegged the total size of the Gulf leak at 4.9 million barrels.

"BP agrees with you that it is important to determine the amount of oil that was discharged from the MC 252 well into the Gulf of Mexico," Douglas Curtis, a partner in the litigation/controversy and securities departments at the law firm WilmerHale, wrote to Markey yesterday. "BP is continuing to evaluate available information, including estimates previously released by the [government scientific team]."

The question of how much oil spewed into the Gulf is crucial to determining the size of fines that the Obama administration could impose on BP under the Oil Pollution Act of 1990. Penalties range from $1,100 to $4,300 per barrel spilled. BP's accounting of the size of the disaster could also prove crucial in other civil lawsuits filed against the company.

"As if we needed it, this is a clear signal that BP intends to fight the same numbers they claim to have helped create about the size of the spill," Markey said in a statement about the letter. He called on the oil giant "to accept these numbers in order to move on to the vital task of Gulf restoration, instead of endless litigation."

The most recent spill-size projections from the government's Flow Rate Technical Group mark this year's Gulf gusher as the worst accidental release over water in world history, or nearly 20 times the size of the 1989 Exxon Valdez spill (Greenwire, Aug. 3).

That estimate, which amounts to a high of 62,000 leaked barrels per day, came after federal scientists were forced to revise initial predictions upward, from 5,000 barrels per day to between 20,000 and 40,000 barrels per day and later to the new level.

Click here to read the letter from Curtis to Markey.