Tesoro Corp. says part of a broken pipeline that leaked 20,600 barrels of crude oil in a wheat field in northwestern North Dakota will be sent to an independent lab for testing. The Texas-based company says Tuesday that it will "remove, reroute and replace" a 200-foot section of pipe. The company says federal regulators have approved the plan. Company officials are investigating what caused the hole in the 6-inch steel pipeline. The spill was discovered on Sept. 29 by a farmer harvesting wheat. Officials say the spill has been contained and no water sources have been contaminated. Tesoro says it's developing plans to restart the pipeline, but the timeline is not yet known.