The Deepwater Horizon oil rig burns in the Gulf of Mexico on April 21, 2010, more than 50 miles southeast of Venice on Louisiana's tip.

Oil from the Deepwater Horizon spill floats on the water as the sky is reflected in sheen on Barataria Bay, off the coast of Louisiana on June, 7, 2010.

Oil floats in the waters of Chandeleur Sound, La. two weeks after the explosion of the Deepwater Horizon oil rig in the Gulf of Mexico.

People gather near crosses for the 11 workers who died in the Deepwater Horizon oil rig explosion, during a vigil to mark the first anniversary of the BP oil spill on a beach in Grand Isle, La.. The large cross in the center is for the Gulf of Mexico.

A shrimp boat is used to collect oil with booms in the waters of Chandeleur Sound, La.

A boat is surrounded by oil near the site of the Deepwater Horizon explosion and oil spill on Tuesday, June 15, 2010.

Patches of oil from the Deepwater Horizon spill are seen underwater in the Gulf of Mexico, south of Venice, La., on Monday, June 7, 2010.

A brown pelican stained with oil takes flight while a bird rescue team tries to capture it for cleaning on June 5, 2010 in Grand Isle, Louisiana.

Crude oil from the Deepwater Horizon oil spill washes ashore in Orange Beach, Ala. on June 12, 2010. Large amounts of the oil battered the Alabama coast, leaving deposits of the slick mess some 4 inches to 6 inches thick on some parts of the beach.

Melanie Driscoll, director of Bird Conservation for the Louisiana Coastal Initiative, holds up oil residue on April 8, 2011. The Louisiana Department of Wildlife & Fisheries gave a press tour to show the effects of the Deepwater Horizon oil spill in Port Sulphur, La.

The letters BP, inscribed in sand and oil by a Greenpeace activist, are shown on a beach at the mouth of the Mississippi River on May 17, 2010 near Venice, La.

A protester's sign lies outside a meeting where residents were able to get face-to-face time with BP and government officials at one of a series of open houses in New Orleans on June 23, 2010.

A member of Louisiana Gov. Bobby Jindal's staff reaches into thick oil on the surface of the northern regions of Barataria Bay in Plaquemines Parish, La. on June 15, 2010.

A Capitol Hill police officer arrests Diane Wilson on Capitol Hill in Washington on June 17, 2010. BP CEO Tony Hayward was testifying before the Energy and Environment subcommittee on Oversight and Investigations hearing on the role of BP in the Deepwater Horizon explosion and oil spill.

Demonstrators hold up signs on Capitol Hill in Washington on Monday, May 17, 2010, as BP America Chairman and President Lamar McKay, right, waits his turn to testify before the Senate Homeland Security and Governmental Affairs Committee hearing to assess the nation's response to BP PLC's Deepwater Horizon oil spill.

BP Senior Vice President Kent Wells rubs his eyes while testifying during the Deepwater Horizon joint investigation hearings Aug. 26, 2010. The hearings were held by the U.S. Coast Guard and the Interior Department's Bureau of Ocean Management, Regulation and Enforcement in Houston .

Robert Kaluza, a BP well site leader from the Deepwater Horizon oil rig explosion, enters Federal Court before he is arraigned on manslaughter charges in New Orleans on Wednesday, Nov. 28, 2012.

Robert Kaluza, a BP well site leader from the Deepwater Horizon oil rig explosion, talks with his attorneys Shaun Clarke, left, and David Gerger, right, as they enter Federal Court before he is arraigned on manslaughter charges in New Orleans on Wednesday, Nov. 28, 2012.

Activists holds signs during a protest in front of the Hale Boggs Federal Building on the first day of the civil trial against BP in the 2010 Gulf of Mexico oil spill on Monday, Feb. 25, 2013.

An activist holds a sign during a protest in front of the Hale Boggs Federal Building on the first day of the civil trial over the 2010 Gulf of Mexico oil rig spill on February 25, 2013 in New Orleans, Louisiana. Eleven men were killed during the accident and over 4 million barrels of oil spilled into the Gulf of Mexico in 2010.