In North Dakota, more than 20,000 barrels of crude oil have leaked into a wheat field from a pipeline owned by the company Tesoro. The leak covered about seven acres of land, the size of seven football fields. It was roughly four times the size of the ExxonMobil pipeline leak in Mayflower, Arkansas, in March. A farmer found the leak on September 29, but North Dakota Gov. Jack Dalrymple said he was only told about it Wednesday night because its size had been underestimated. He said the state is now reviewing its procedures for reporting spills.