The U.S. Coast Guard expanded its search for the source of the leak that spewed 1.1 million gallons of oil in the Gulf of Mexico south off South Pass on November 16, 2023, as the source of the leak remains unknown.

The Coast Guard plans to include other pipelines near a Main Pass Oil Gathering line that was shut down on the day the spill was discovered.

So far, a team of divers and operators of an underwater remotely operated vehicle have inspected more than 39.5 miles of the MPOG pipeline, with "no damages or indications of a leak identified," the Coast Guard said in a news release.

"ROVs have also inspected more than 6 miles of surrounding pipelines, also with no damages or indications of a leak identified," the release said.

The Coast Guard has set up a "unified command," made up of representatives of federal and state agencies and of Main Pass, to oversee the spill response. Main Pass has been identified as the "potential responsible party" for the incident, since the oil was originally reported as being released from the company's pipeline.

"The cause and source of the incident remain under investigation," the Coast Guard release said. 
"Overflights conducted November 20 to date have observed no new oil from the suspected release. Recent wildlife and shoreline assessments identified no wildlife or shoreline impacts."

The Coast Guard did not immediately release information on the owner of the other pipelines being investigated for leaks and did not say whether Main Pass has restored service in its main pipeline.

According to the Bureau of Safety and Environmental Enforcement, that 67-mile pipeline is used to funnel crude oil to shore from seven offshore well operators in the Gulf, all of which were shut in when the spill was identified.