Macondo leak mystifies

An ROV surveys accident site in October

Investigators unable to find source of sheen

Investigators have been unable to locate the source of a sheen spotted near the Deepwater Horizon accident site, the Federal On-Scene Coordinator announced on 18 December 2012.

State representatives of Louisiana, Mississippi and Florida joined personnel from BSEE, BOEM, the U.S. Coast Guard, BP and Transocean to oversee the fourth ROV survey of the Deepwater Horizon accident site in Mississippi Canyon block 252. The survey inspected the integrity of the Macondo well, associated relief wells, and wreckage site including the drilling rig, riser, and cofferdam.

No source for the sheen was discovered during the mission. However, BP said the ROVs witnessed a white, cloudy substance rising from several places on the overturned rig. Samples were collected and further analysis is pending.

"No apparent source of the surface sheen has been discovered by this effort," said Capt. Duke Walker, Federal On-Scene Coordinator for Deepwater Horizon. "Next steps are being considered as we await the lab results of the surface and subsurface samples and more detailed analysis of the video shot during the mission."