Detroit Free Press Editorial Board

Little Traverse Bay. Mackinaw City. Mackinac Island. Cheboygan. St. Ignace.

Each could be at risk if the twin pipelines known as "Line 5," carrying some 23 million gallons of light crude oil a day through the Straits of Mackinac ruptures — part of 700 miles of vulnerable Michigan coastline identified in new research modeling 840 spill scenarios. In almost every scenario, Mackinac and Bois Blanc Islands and Mackinaw City — all places at the heart of Michigan's economically significant tourism industry — were damaged.

Study: 700 miles of coastline in Straits oil spill danger zone

The research, performed by scientists at the University of Michigan's Water Center and the National Oceanic and Atmospheric Administration's Great Lakes Environmental Research Laboratory, is a grim reminder of the risk posed by the aging Line 5. The pipeline is owned by Canada-based oil transporter Enbridge, the same company responsible for a devastating 2010 oil spill on the Kalamazoo River.

A reminder, because the possible environmental consequences of a failure in the 62-year-old pipeline are well known among Michigan's environmental activists, regulators and state legislators. Enbridge insists the pipeline is in satisfactory condition, but environmental advocates say the company won't make the information to back up its claims public.

Because of strong and complex currents, one researcher has called the straits "the worst possible place for a Great Lakes oil spill." The U.S. Coast Guard has repeatedly raised alarms about its ability to effectively respond to a spill on the Great Lakes, where high seas could make deployment of the ships typically dispatched to such spills unsafe. And watching a set of videos produced by the University of Michigan's Graham Sustainability Institute is like watching an environmental horror film. The videos show how oil spilled in the straits would disperse — spreading, in one scenario, almost to Michigan's thumb.

Suffice it to say, we're convinced: Transporting oil through the straits is too risky — and the Great Lakes are too important to risk. But the possible threat — and the state and nation's questionable capacity to resolve such a spill — haven't spurred many in Lansing to action.

While pipeline safety and capacity are regulated by a federal agency, Gov. Rick Snyder and Attorney General Bill Schuette have the authority to ask a judge to vacate the easement agreement that effectively allows Enbridge to function as an oil transporter. But neither man has done so.

Oil spill, high waves: A Great Lakes disaster scenario

Pipeline bill would give Great Lakes greater protection

A task force led by Schuette and former Michigan Department of Environmental Quality Director Dan Wyant (whose agency's role in the Flint water crisis prompted his resignation late last year), concluded in a 2015 report that Enbridge had violated the decades-old agreement by not maintaining the pipeline's support structures.

The task force criticized the pipeline in plain terms: The pipeline could never be built today, Schuette said, and its "days are numbered." But the task force stopped short of recommending a moratorium on flow of oil through the pipeline or phasing its operations out over time. Instead, the task force recommended a third party assess the pipeline risk, review Enbridge's financial assurances, and examine alternatives to the existing pipeline route.

An environmental group has identified existing Midwest pipelines that could replace Line 5, like the "Alberta Clipper" pipeline and Enbridge's Line 6B, which don't run through the Great Lakes.

We understand the need to balance business and the environment, safety and the well-being of Michiganders, many of whom depend on the products Enbridge transports. But care of the Great Lakes trumps all.

The state and federal governments need to bring urgency to the search for an alternative transport scheme before any of the devastating scenarios depicted in the UM/NOAA study make the leap from disturbing simulation to real-world catastrophe.