Line 5 carries synthetic crude oil from Superior, Wisconsin. The original sources are tar sands bitumen from Canada, which has been refined to a “light” oil or “high sour.” Enbridge states that “heavy” diluted bitumen, which is a less refined and more corrosive product that was released into the Kalamazoo River in 2010, does not currently run through Line 5. This pipeline also carries crude oil that originated in the Bakken oil fields of North Dakota. In short, much of the oil transported through Line 5 originates in western Canada, is shipped through Michigan and the Great Lakes, and refined in Canada for markets back in Canada.
Tar sands oil is 82% more toxic in the ground than conventional oil. It also sinks to the bottom of waterways unlike conventional oil – making it very expensive and extremely difficult to clean up. Usually it is easier for companies like Enbridge to leave tar sand oil spills behind and cover them with earth.
“Former Enbridge employee John Bolenbaugh has since blown the whistle on this practice. Here he speaks at a state permit meeting in Michigan for a 64 year old pipeline running underneath the Mackinaw River. Should this pipe bust, it would contaminate the largest fresh water source in the world. ” whistleblower John Bolenbough