Ellington

NEW ORLEANS (AP) — The federal judge presiding over a trial arising from the nation's worst offshore oil spill says it could be difficult to determine how much crude spewed into the Gulf of Mexico from BP's busted well in 2010.

U.S. District Judge Carl Barbier noted during a hearing Thursday that there wasn't a "meter" attached to BP's blown-out Macondo well.

Barbier heard testimony earlier this year for the trial's first phase about the possible causes of the deadly disaster. Determining how much oil spilled into the Gulf is a topic for the trial's second phase, set to begin Sept. 16.

BP claims the federal government overestimated the size of the spill. The government estimated more than 200 million gallons spewed from the well, including more than 34 million gallons that were collected.