While the trans-Alaska oil pipeline is pumping about 340,0000 barrels a day, pipeline crews are expected to start welding a bypass line Friday at Pump Station No. 1, which was fabricated in sections in Fairbanks.
More than 550 people are working on the repair and monitoring project, including about 250 at the farthest north pump station. A 36-hour pipeline shutdown is expected, perhaps starting as soon as Friday night, to complete the bypass.
All the equipment for the bypass operation is expected to be on hand Friday morning.
Meanwhile, the latest figures show that 5,670 gallons of oil has been collected from the leaking pipe, about 145 gallons an hour.
The leak is emptying into a five-foot tank that could hold 800 gallons, but the pipeline crews are keeping the oil layer to about an inch, using a vacuum truck to pick up the oil, which will go back in the pipeline.
"No oil has been observed during ongoing surface and subsurface monitoring of soil in the vicinity of the booster pump building or during inspections of the perimeter of the pump station’s gravel pad," according to a situation report released Wednesday afternoon.
A 10-foot hole dug near the building shows no signs of oil leaking underground, the Department of Environmental Conservation said.
Alyeska has placed temperature monitors at 95 points along the pipeline to check oil temperatures and plan to add 18 more. Ice in the line, caused by low temperatures and hte separation of oil and water, is a big concern.
The pipeline cleaning pig that had been stuck near Wickersham Dome north of Fairbanks is expected to reach Pump Station No. 8 later today and it is to be trapped between two valves while the oil flows through a bypass route, the state said. A second pig that had been near Thompson Pass is expected to reach Valdez today.
Pump Station No. 8 doesn't have a facility to remove the cleaning devices so the pig will be kept in the main pipeline. Alyeska prepared a bypass over the past several days to allow oil to flow around it.