Those fortunate enough to travel through the Straits of Mackinac have experienced the beauty of Lake Michigan and Lake Huron emerging as one as you pass through the gateway of mountainous sand dunes in the Lower Peninsula to steep cliffs and adventure in the Upper Peninsula.

But one aspect of the Straits of Mackinac that I’m sure you’re unaware of is the presence of a 20 million gallon a day oil pipeline running right under our two Great Lakes.

Sitting just below the surface of our waterway is Line 5 of Enbridge’s Lakehead system, which connects the Alberta tar sands region to refineries here in Michigan and the Midwest. This pipeline is almost 60 years old, and Enbridge has plans to expand it without replacing it! This expansion is part of a larger strategy to deliver Alberta tar sands oil to the east coast for export.

If the company Enbridge sounds familiar to you, that’s for good reason. Last July, Enbridge was the pipeline operator that spilled nearly 1 million gallons of tar sands oil into the Kalamazoo River watershed. This spill went unnoticed, by Enbridge, for nearly 13 hours before a local utility brought the devastating incident to their attention. Fifteen months later, the impacted sections of the Kalamazoo River remain closed to the public as air and water monitoring continues along with the clean-up of submerged oil.

Imagine how an oil spill and closure like that would impact our already suffering economy, fragile ecosystem and the billions of dollars we have invested into restoring and protecting our Great Lakes.

Adding to the concern and risk is how this industry is regulated, or lack thereof.  Enbridge is not required to disclose to federal regulators when product in that pipeline changes. This means that Line 5 could be transporting the more corrosive, toxic and unstable raw tar sands crude at any time without notifying anyone of the change.

One Year Later, Michigan Tar Sands Oil Spill - Ceresco Dam
Tar sands oil in the Kalamazoo River, one year later.

To date, Enbridge denies that the raw form of tar sands oil travels through Line 5, known as diluted bitumen. But disclosure of when product changes is not required by the federal oversight agency, Pipeline Hazardous Materials Safety Administration, because they still have not updated rules and regulations around this new product. In their eyes, crude is crude.

Ask anyone from the Kalamazoo River area if they think crude is crude.

With the Kalamazoo River oil spill this past July, Enbridge and EPA officials did not learn quick enough that dealing with a tar sands oil spill is much more difficult than dealing with a conventional oil spill. Simply put, conventional clean-up techniques do not work because tar sands oil sinks in water, rather than floats, so the EPA and Enbridge are writing the book on how to clean up tar sands oil as they go along.

Given that pipeline operators and oversight agencies admit that they do not know how to properly respond to a tar sands oil spill, I would hope that Congress and the agencies responsible for pipeline safety would block future projects until proper safeguards are in place to protect our communities and natural resources from another disaster.

To learn more about ways you can help prevent expansion of tar sands pipelines and protect wildlife, please visit National Wildlife Federation Action Fund.