Pipelines leak because they are pressurized pipes that are filled with oil. The amount they leak annually is comparable to large tanker spills, but since it occ

Pipelines leak because they are pressurized pipes that are filled with oil. The amount they leak annually is comparable to large tanker spills, but since it occurs constantly at a low level in a way that is less visible this type of leak is under reported. This also has a carbon and environmental cost that must be weighed against alternatives.