LANSING, Mich. (WOOD) — It starts with a split in a 20-inch pipe 200 feet below the Straits of Mackinac. Twenty-four hours later, a slick has formed, leaving the shores of Lakes Huron and Michigan coated in oil. Mackinac Island is a disaster zone, and one of the state’s most pristine and vulnerable areas sits tarred in an oily black sludge.

That is the nightmare scenario as laid out by researchers at the University of Michigan if a spill like the 2010 Kalamazoo River disaster were to happen to Enbridge Energy’s Line 5. It was part of a computer simulation, but the dangers are very real.

“Any leak would be a disaster. Any type of spill would be a disaster, let’s make that very clear,” Michigan Attorney General Bill Schuette said.

Line 5 is the pipeline that runs hundreds of miles through Canada and Michigan, transporting 23 million gallons of light crude and liquid natural gas each day. At 61 years old, it sits underneath the Straits of Mackinac coated in layers of invasive zebra mussels and is subject to the random currents of the Great Lakes. Environmentalists say a spill would devastate the Great Lakes economy.

“We need to ask for more and then know more to ensure we don’t have a problem going forward,” Michigan Department of Environmental Quality Director Dan Wyant said.

Last week, Wyant and Schuette unveiled the results of a year-long study of pipelines running through the state, including the vulnerable Enbridge Line 5. The task force they chair issued four specific recommendations regarding the pipelines underneath the Straits of Mackinac, including a ban on heavy crude oil through the line, and adequate insurance if something were to happen.

But some wonder if the state is acting with enough urgency.

“It lacks the sense of urgency that we would like to see. There has to be more information to know to keep the Great Lakes safe,” said Liz Kirkwood of the environmental group For Love of Water.

Kirkwood says the plan in very straightforward in it its language, but lacks enforcement.

How catastrophic would a spill under the Straits be? The University of Michigan study, which was commissioned last year by the National Wildlife Federation, found the Straits would be the “worst possible place” for a Great Lakes oil spill.

Computer simulations are unsparing when it comes to the tracking where the oil would go if one million gallons leaked, like it did into the Kalamazoo River in 2010. Shorelines along both Lakes Michigan and Huron would be contaminated, including Mackinac Island, and would stretch as far away as Rogers City.

Enbridge Energy insists in its public filings that Line 5 is safe and that it doesn’t push heavy crude through the pipe. The energy giant has told state officials that it has no plans and sees no need to replace it.

Michigan State Police emergency managers say they can’t predict everything.

“It’s about managing risk. We’re not going to fully eliminate this risk… We can manage it and do the best that we can,” MSP Capt. Chris Kelenske said.

But there has to be a tradeoff. Both state officials and environmentalists say piping petroleum through the region is still the preferred option to get the oil to market. Alternative transportation methods like tanker ships, rail and trucks offer plenty of other downsides.

But Line 5 is aging and won’t last forever. Schuette said there needs to be a future alternative.

“You would not build the Straits pipeline in this decade,” he said. “It’s doubtful it’ll be operational in future decades. That’s all I have to say.”

The task force Schuette chairs seeks cooperation of both energy companies and lawmakers to minimize the state’s risk.