The clean-up of an oil spill from TransCanada Corp’s Keystone pipeline may last several weeks, South Dakota’s environmental regulator said on Wednesday, but it is still unclear when the key artery will restart. An aerial view shows the darkened ground of an oil spill which shut down the Keystone pipeline between Canada and the United States, located in an agricultural area near Amherst, South Dakota, U.S., in this photo provided November 18, 2017. Last week, the Keystone system linking Alberta’s oil sands with U.S. refineries spilled 5,000 barrels in rural northeastern South Dakota, four days before neighboring Nebraska voted to remove a big regulatory obstacle for the company’s Keystone XL project. “We expect it to take several weeks. Our focus is making sure they do that clean-up in accordance with our regulations,” said Brian Walsh, environmental scientist manager for the South Dakota Department of […]