Alaska News

State finds cause of Chukchi Sea mystery sheen

A year-old mystery on the Chukchi Sea has been solved, according to state officials who say the source of a recurring oil sheen on waters near Shishmaref has finally been identified.

According to Tom DeRuyter, a spokesman with the state Department of Environmental Conservation, the source of the sheen was a fuel line near a tank farm on Sarichef Island. Shishmaref, a community of about 600 people roughly 100 miles southwest of Kotzebue, is situated on the island.

DeRuyter said the problem was a leak at a joint between a gasoline line in the tank farm and a marine header, a pipe that barges visiting Shishmaref use to pump fuel to the farm.

According to a DEC situation report, the faulty spot was identified through hydrostatic testing and a weld was made to fix the leak.

Jessica Starsman, one of the DEC responders who visited the island, said wildlife hasn't been affected by the sheen -- but authorities still don't know how much fuel leaked.

"We were unable to come up with a determination," Starsman said. "We don't know when the leak actually formed, so it's hard to come up with that number."

The sheen and its gasoline-like odor, first reported by a village public safety officer in June 2014, prompted an investigation by DEC as well as the U.S. Coast Guard.


A year later, radio station KNOM reported that a new sighting of the sheen prompted DEC to return to the island – but an analysis was only able to identify the material as "weathered gasoline and diesel," found on beaches and water near the Shishmaref Native Store.

DeRuyter said the leak's persistence was due in part to a valve that was improperly left open, allowing latent fuel in the lines to reach the faulty section of the marine header.

"The isolation valve at the dispensary should have been closed; that would have completely isolated the marine header from the dispensary and the tank farm," DeRuyter said. "But from this hole in this line, they had fuel that was continuing to leak out."

DeRuyter said 16 months was an unusually long time to isolate and repair the source of a fuel sheen. Part of the reason for the delay was that there were many places from which the fuel could have been leaking.

"There were a lot of sources possible, including someone fueling their snowmachine in the wintertime," DeRuyter said. "There were a lot of things that we looked at before we were able to identify it through the hydrostatic testing."

Despite the completion of repairs, DeRuyter said that neither a full environmental assessment of the area nor cleanup work had been finished. He said DEC considers the Native store the "potentially responsible party" for the leak's costs, based on its ownership of both the marine header and the leaked gasoline.

"The source of this leak has been fixed and there's some confidence in that, but there's still some cleanup to be completed and that will be addressed in future," DeRuyter said.

Chris Klint

Chris Klint is a former ADN reporter who covered breaking news.