Managers hope to finalize repairs today to a pipeline that delivers refined fuels from the Tesoro Alaska refinery in Nikiski to Anchorage.
If all goes well, the pipeline should be back in service this afternoon, said Ron Noel, Tesoro Alaska vice president and general counsel.
State officials said the leak was discovered Tuesday night when Phillips Petroleum Co. workers found jet fuel on the ground near the buried Tesoro pipeline. The spill site is near Mile 35 Kenai Spur Highway -- about 13.75 pipeline miles from the refinery. It lies a couple hundred yards from the highway between Bishop Creek and the Swanson River in Captain Cook State Recreation Area.
The pipeline, which carries gasoline, diesel and jet fuel, has been shut down since the leak was discovered. However, that has not yet affected operations at the refinery or fuel sales in Anchorage, Noel said. So far, Tesoro has had enough fuel at its Anchorage terminal to meet demand there and enough storage capacity in Nikiski to absorb production from the refinery. If the pipeline is shut down for long, Tesoro will barge fuel from Nikiski to Anchorage, Noel said.
The 10-inch-diameter pipeline is buried 4 to 6 feet deep in the area of the spill. Rising fuel killed grass and other vegetation in an area about 150 yards long and 25 yards wide along the pipeline corridor.
Tesoro activated Cook Inlet Spill Prevention and Response Inc. to help find and repair the leak and to clean up spilled fuel. On Wednesday, cleanup workers excavated the suspect section of pipe and located several pinhole leaks on a weld. They clamped a sleeve over the pipe to stop the fine spray of fuel that emanated from the holes even with the pipeline shut down.
Tesoro has had that sleeve on hand for years, probably since the pipeline was built in 1976, Noel said. The original plan was to weld it into place to complete the repair. But Tesoro could find no records to document its composition.
"Without that, there's no way you can do a certified weld," Noel said.
So, Tesoro called the sleeve's manufacturer in Louisiana. The manufacturer could not provide the necessary documentation, either, Noel said, but it had another sleeve on hand. That should arrive today, and workers should have it clamped and welded into place by late this afternoon.
Even then, though, Tesoro will run the pipeline at just 90 percent of its usual operating pressure, he said.
Tesoro has good reason to take that precaution. The leak discovered Tuesday was at the site of an anomaly discovered by recent work with smart pigs -- tools fed through the pipeline to detect corrosion and anomalies in the shape of the pipe. The pigs discovered several other anomalies Tesoro has not yet investigated, Noel said.
"We won't go to full pressure until we inspect those other areas and get approval from the Department of Transportation," he said.
Tesoro may not be able to inspect some of the anomalies until winter cold freezes boggy ground, he said.
Neither Tesoro nor state officials had any estimate yet of the amount of fuel that spilled from the leak. Nor do they know whether the spill includes diesel and gasoline in addition to the jet fuel initially detected. Noel said cleanup workers are taking soil borings and water samples to see how far the contamination has spread. They already are hauling out contaminated soil, and stockpiling that at the refinery until it can be treated.
"It's going to be a lot of dirt," Noel said.
Tesoro expects to submit a cleanup plan for state approval next week, he said.
Leslie Pearson, the Alaska Department of Environmental Conservation on-scene coordinator, said some fuel has reached a foot-wide unnamed stream downhill from the spill site.
"They were out there this morning and noticed a rainbow sheen on that creek," she said.
Workers have strung booms across the creek to keep fuel from flowing downstream to Bishop Creek. They also are digging ditches between the spill site and the unnamed creek to intercept any additional fuel that may drain toward the creek.
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