Oil in new Gulf slick matches that of 2010 spill

The oil in a slick detected in the Gulf of Mexico last month matched oil from the Deepwater Horizon spill two years ago, the Coast Guard confirmed Wednesday night, ending one mystery and creating another. “The exact source of the oil is unclear at this time but could be residual oil associated with the wreckage or debris left on the seabed from the Deepwater Horizon incident,” says the Coast Guard, adding, “The sheen is not feasible to recover and does not pose a risk to the shoreline.” One government expert says the thin sheen, just microns thick, was 3 miles by 300 yards as of Wednesday. Some oil drilling experts have said it’s unlikely that BP’s Macondo well, which suffered a blowout on April 20, 2010, is leaking again, given the extra precautions taken when it was finally sealed after spilling nearly 5 million barrels of crude into the Gulf. BP declined to comment. But a BP internal slide presentation says the new oil sheen probably came from the riser, a long piece of pipe that had connected the drilling rig to the well a mile below the sea surface. The Washington Post has the full story here.