**FILE** White smoke rises Aug. 7, 2012, from the Chevron oil refinery in Richmond, Calif., during a controlled burn conducted the morning after a toxic fire at the refinery. (Associated Press/The Contra Costa Times)
Zach Johnson reacts after hitting an eagle shot from the 18th fairway during the third round of the Chevron World Challenge at Sherwood Country Club, Saturday, Dec. 3, 2011, in Thousand Oaks, Calif. (AP Photo/Los Angeles Daily News, John McCoy)
Tiger Woods tees off on the second hole during the second round of the Chevron World Challenge golf tournament at Sherwood Country Club, Friday, Dec. 2, 2011, in Thousand Oaks, Calif. (AP Photo/Danny Moloshok)
George Buck, chief operating officer for Chevron's Brazilian division, said Sunday the spill occurred because Chevron underestimated the pressure in an underwater reservoir. (Associated Press)
An aerial view shows a boat crossing an area of the oil spill in an offshore field operated by Chevron at the Bacia de Campos in Rio de Janeiro. (Associated Press)
Tiger Woods reacts to his tee shot on the third hole during the second round of the Chevron World Challenge golf tournament at Sherwood Country Club on Friday, Dec. 3, 2010, in Thousand Oaks, Calif. (AP Photo/Mark J. Terrill)
Graeme McDowell, of Northern Ireland, applauds the crowd after winning the Chevron World Challenge golf tournament in sudden death at Sherwood Country Club in Thousand Oaks, Calif., Sunday, Dec. 5, 2010. (AP Photo/Gus Ruelas)