Enbridge Pipeline System and lower peninsulas of Michigan before crossing into Ontario, while the southern route circles south of Lake Michigan through Illinois and Indiana before reaching Michigan. There are 59 pumping stations in the pipeline system, and the actual pipes range in diameter from . One major junction point is in Clearbrook, Minnesota where the pipeline connects to the Minnesota Pipeline, which carries crude to the Pine Bend Refinery in Rosemount, Minnesota. The North Dakota Pipeline Company system of pipeline also has a connection in Clearbrook, linking the Mandan Refinery in Mandan, North Dakota. The Murphy Oil refinery in Superior, Wisconsin, is
Pipeline transport employee in Michigan. Although the Pipeline and Hazardous Materials Safety Administration (PHMSA) has standard baseline incident frequencies to estimate the number of spills, TransCanada altered these assumptions based on improved pipeline design, operation, and safety. Whether these adjustments are justified is debatable as these assumptions resulted in a nearly 10-fold decrease in spill estimates. Given that the pipeline crosses 247 miles of the Ogallala Aquifer, or 14.5% of the entire pipeline length, and the 50-year life of the entire pipeline is expected to have between 11 – 91 spills, approximately 1.6 – 13.2 spills can be expected to occur over