Up to 4,200 gallons of crude oil discharged from a well into the mouth of the Mississippi River, the U.S. Coast Guard said.
The Coast Guard and other agencies were responding Tuesday to the spill in the Main Pass.
Texas Petroleum Investment Co. owns the well, the Coast Guard said. The cause of the incident is under investigation.
The agency said crews from Coast Guard Air Station New Orleans and Southern Seaplane are flying over the site and surrounding areas to make assessments.
The owner of the well has contracted with OMI Environmental Solutions and Clean Gulf Associates, private oil spill response companies, for clean-up operations.
The Coast Guard, Louisiana Department of Environmental Quality, Louisiana Oil Spill Coordinators Office and Louisiana Department of Wildlife and Fisheries are also overseeing the response.
The Coast Guard said in its release 4,200 gallons was the “estimated maximum potential” amount discharged in the spill.
The agency last week said 840 gallons of oil leaked from a pipeline into the river’s South Pass July 28. Texas Petroleum Investment Co. also owned that pipeline.
The Coast Guard reported workers were able to secure the pipe and a containment boom was in place.