Holly Energy Partners-Operating L.P. and Osage Pipe Line Company LLC have agreed to pay $7.4 million in penalties for violating the Clean Water Act. An investigation conducted by the U.S. Environmental Protection Agency (EPA) and Justice Department began after a pipeline rupture caused crude oil to spill onto land owned by members of the Sac and Fox Nation in Oklahoma. The rupture and subsequent leak caused 300,000 gallons (7,110 barrels) of crude oil to be discharged into Skull Creek.