The U.S. Coast Guard in New Orleans responded to a report of an oil spill in the Mississippi River in St. John the Baptist Parish on Sunday.
About 12:30 a.m., the Coast Guard office in New Orleans received a report that potentially 4,200 gallons of fuel oil had been released into the river at the Pin Oaks Terminal in Mount Airy.
Coast Guard incident management teams conducted flights over the area to assess the impact, according to a news release.
The agency said at 3:45 p.m. that it had concluded its response after determining that the maximum amount of oil released was approximately 100 gallons.
The waterway remained open.
The cause of the incident is under investigation.