A "who's who" of environmental groups say a 67-year-old pipeline in the straits of Mackinac could be a serious threat to the Great Lakes.
The pipeline is owned by Enbridge.
Howard Learner is head of the Environmental Law and Policy Center.
"It's an old aging pipeline," says Learner. "We can't afford to have happen in the Great Lakes what happened with the Enbridge pipeline and the oil spill in the Kalamazoo River. You know, it's already been a couple of years and we are still cleaning it up. "
In 2010, more than a million gallons of oil spilled into the Kalamazoo River after an Enbridge pipeline rupture.
Lerner's group, along with 16 other major environmental groups in Michigan, have sent a letter requesting an urgent meeting with Governor Snyder about the pipeline.
Learner says Enbridge may not be maintaining the pipeline properly, including not installing enough supports for the pipeline.
And he says the company may be sending oil through it under too much pressure, but there's no way to know until the state forces the company to disclose the information.
There's also a question whether state regulations written more than 60 years ago meet current standards.
*Correction - A previous version of this story said "more than a million barrels of oil spilled." It was more than a million gallons. Story corrected above.