The state has concluded that just three gallons of liquid escaped from one of Hilcorp’s platforms into Cook Inlet in early April.
The spill was reported on April 1, when workers on one of Hilcorp’s oil platforms felt an impact and then spotted a sheen on the water. At first, the state thought it was a crude oil leak from one of the pipelines connected to the platform.
But according to a situation report released today by the Alaska Department of Environmental Conservation, the leak’s source was a feed line for the platform’s gas flare system, not the underwater oil pipeline.
According to Hilcorp, a liquid called natural gas condensate had formed in the line. The company arrived at its 3-gallon estimate based on how much condensate the line can hold and how much was recovered.
The state also reports that Hilcorp restarted the crude oil pipeline on May 2. Four overflights were conducted afterward, and the state reports that no sheen or release was observed.
After determining the oil pipeline wasn’t the source of the spill, the federal Pipeline and Hazardous Materials Safety Administration has withdrawn a corrective order they issued to Hilcorp after the incident that would have required more stringent daily monitoring of the pipeline.
Hilcorp was forced to shut down several other pipelines and platforms in Cook Inlet this spring, including platforms connected to a fuel line that leaked natural gas for several months before ice conditions allowed divers to make repairs.
Last week, the company announced a new pipeline project to eliminate the need to store oil at the Drift River Terminal, which is located at the base of an active volcano.
Elizabeth Harball is a reporter with Alaska's Energy Desk, covering Alaska’s oil and gas industry and environmental policy. She is a contributor to the Energy Desk’s Midnight Oil podcast series. Before moving to Alaska in 2016, Harball worked at E&E News in Washington, D.C., where she covered federal and state climate change policy. Originally from Kalispell, Montana, Harball is a graduate of Columbia University Graduate School of Journalism.