Oil and hazardous liquid pipelines, also known as transmission lines, carry crude oil, bitumen (the oil extracted from tar sands), gasoline, diesel, jet fuel, butane, condensate, and other fuels from drilling areas to refineries and markets.
Interstate lines, which can cross multiple state boundaries and stretch for hundreds of miles, make up almost 70% of the national oil and liquids pipeline network.
Interstate oil and liquids pipelines are not permitted and regulated by a single federal agency. Instead, companies seek approvals from state regulatory agencies and any federal agencies relevant to a specific project. The Pipeline and Hazardous Materials Safety Administration (PHMSA) oversees safety, and finalized new regulations for oil and liquids pipelines in early 2017.