Feds approve plan to identify source of Gulf sheen

Officials said in a news release that the federal on-site coordinator approved the joint plan on Thursday. Coast Guard Capt. Duke Walker had required the plan, and federal officials informed BP and Transocean they might be held responsible for the costs of identifying the source and the cleanup.

Federal scientists and BP say oil appears to have leaked last month from the drilling wreckage lying at the bottom of the Gulf of Mexico near where a BP well blew out in 2010, causing the nation's worst offshore spill.

A probe started after a sheen was discovered Sept. 16 in the waters near the site indicates the oil may have seeped from a mile-long metal tube, called the riser, which connected the Deepwater Horizon drilling rig to the Macondo well.

The plan calls for "satellite observations and mobilizing remotely operated vehicles to examine the original Macondo well area including the wreckage, debris and the riser on the sea floor," according to the news release.