Anchorage: Oil resumed flowing through the trans-Alaska pipeline Wednesday, but at only two-thirds the rate before a three-day shutdown caused by a leak.
The shutdown turned out to be the second-longest in the history of the line that transports about 13 per cent of America's domestically produced oil.
By Wednesday morning, the pipeline was moving crude from the largest US oil field at a rate of about 400,000 barrels a day.
Before Saturday morning's shutdown, it was carrying about 630,000 barrels a day.
The 1,287km pipeline was restarted Tuesday evening despite the leak near a Prudhoe Bay pump station. Oil continues to seep into the basement of the booster pump building, the last stop before oil enters the main line for the trip to a Valdez marine terminal where oil is loaded onto tankers heading for the West Coast.
Worsening leak
The amount of leaking oil worsened when the pipeline was restarted.
More than 8,700 litres of oil flowed into an 3,028 litre containment tank between 8pm Tuesday and 4pm Wednesday, and vacuum trucks were continuously removing it, said Stefani Bell from Alyeska Pipeline Company.
The amount is about half of what had leaked from the broken pipe so far, she said.
Alyeska received approval from state and federal regulators to restart the pipeline even though a bypass pipe to circumvent the leak was days away from being installed.
Officials wanted to restart the pipeline out of concerns that ice was forming in the line and wax from the oil was accumulating during the prolonged shutdown.
One of the main concerns was about a device called a cleaning pig that was in the line. If there was ice and wax in the line when it was restarted, the pig could push that material into machinery and damage it, causing another shutdown.
