Subsea inspections at the site of the Deepwater Horizon disaster have failed to determine the source of a mysterious sheen that has been making repeat appearances for months in a region of the Gulf of Mexico. The sheen has been spotted in the vicinity of BP’s blown-out Macondo well, which gushed oil for weeks in 2010, prompting BP to conduct a number of missions under the Coast Guard’s supervision.
According to the U.S. Coast Guard, “an ‘unidentified substance inconsistent with oil’ is emitting from several areas of BP’s Deepwater Horizon rig wreckage, but no sources of leaking oil were identified.”
Investigators have described the substance as a cloudy white fluid that appears to be emerging from the downed rig, which sank to the bottom of the Gulf on April 22, two days after it was rocked by explosions. Eleven workers died in the blast, which led to the worst offshore oil spill ever to hit the U.S.
Relief wells that BP engineers drilled to plug the main oil well and the containment dome that sits on top of the Macondo well were also found to be secure, BP said.
Investigators took samples of the mystery substance for testing.
“No apparent source of the surface sheen has been discovered by this effort,” Coast Guard Capt. Duke Walker said in a statement. “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.”
The persistent sheen has drummed up fears of another oil spill or subterranean leak among residents of the Gulf Coast, who are still recovering from lost wages and business, and extensive environmental damage.
BP said the latest inspection, concluded Dec. 15, was the fourth time the well was inspected and found to be leak-proof.
Coast Guard officials say that the sheen can’t be cleaned up and it poses no threat to the shoreline.