KENAI (AP) -- Unocal has resumed production at a Cook Inlet platform after investigators determined its pipeline was not the source of an intermittent sheen seen nearby in recent weeks.
Unocal resumed production from the King Salmon Platform Saturday evening, after the undersea oil pipeline passed hydrostatic pressure tests, according to company spokesperson Roxanne Sinz. The pipeline again is carrying crude oil from the platform to Trading Bay on the west shore of Cook Inlet.
The sheen had been seen around the platform, often at slack low tide, for about two weeks. On Sept. 12, workers determined that the source was underwater and not on the platform as originally believed.
The following day, Unocal stopped production from the platform and used seawater to flush the oil from the pipeline. Now, the pipeline has been ruled out as a source.
''Now, we're methodically trying to go through what the other possible sources might be,'' Sinz told the Peninsula Clarion.
She declined to speculate on the possibilities.
Workers from Cook Inlet Spill Response and Prevention Inc., the industry spill response group, sampled the sheen Saturday, Sinz said, but there was not much oil to collect. Since then, there has not been enough oil to sample at all. Unocal has hired an Anchorage lab to fingerprint Saturday's sample to help pin down a source.
Unocal conducted side-scan sonar surveys of the area around the platform on Tuesday but found no likely source, according to Sinz. She said debris on the bottom interfered with the sonar. More sonar surveys were scheduled to be conducted Wednesday.
Gary Folley, an environmental specialist with the state Department of Environmental Conservation, said tests on the Saturday sample suggest that the sheen is a product similar to No. 4 diesel, but Sinz said the composition of the leaking fuel has not yet been finally confirmed. Folley said he knows of no undersea pipelines carrying diesel near the King Salmon Platform. Fuel is delivered to the platform by ship, he said.
Unocal has provided the U.S. Coast Guard and DEC with a list of 20 possible sources for the sheen. Folley said the possibilities range from wrecked vessels to drilling muds and miscellaneous leaks.
Peninsula Clarion ©2015. All Rights Reserved.