The U.S. Department of Transportation approved TransCanada Corp.’s plan to restart its Keystone pipeline, which was shut down after a May 29 oil spill. The 1,300-mile pipeline transports crude oil from Alberta to Cushing, Oklahoma. It leaked 400 barrels of oil in North Dakota on May 7 and 10 barrels in Kansas on May 29. On Friday, TransCanada said it had replaced the parts that had caused the leaks. The company provided results of its testing along the Keystone on Saturday, and has been approved to restart as soon as July 5.