Authorities, including the Coast Guard, are cleaning and investigating the release of about 1,200 gallons of oil and water released from a mooring about a mile and half off Barbers Point Sunday. 

The release occurred at noon Sunday during routine maintenance of the hose used to transfer crude oil and refined products between oil tankers and Hawaii Independent Energy’s refinery in Campbell Industrial Park in Kapolei.

Hawaii Independent Energy, with assistance from the U.S. Coast Guard, is investigating how the oil was released. 

Hawaii Independent Energy notified the National Response Center, the U.S. Coast Guard and the Hawaii Department of Health following the spill.

An oil sheen that covers about three-quarters of a square mile is visible about two miles offshore. Based on current tides, the sheen is heading south.

Five vessels are at the scene sweeping the area and using absorbent materials to pick up the oil from the surface of the ocean. A tracking buoy will electronically monitor the sheen’s trajectory and an aerial assessment was conducted Monday morning.