Big oil spill a silent threat to Lake Michigan, Great Lakes

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A study released Tuesday has ratcheted up worries that a 64-year-old mussel-encrusted oil pipeline in northern Lake Michigan threatens an ecological catastrophe.

The study by the National Wildlife Federation said the Enbridge Energy Line 5 pipeline has had nearly double the number of spills that were previously known. Nor were most of the leaks discovered by Enbridge’s remote pipeline detection system, the federation said.

Environmentalists are concerned because 4½ miles of the pipeline lies mostly exposed on the bed of the Straits of Mackinac, at the northern tip of Lake Michigan, where it joins Lake Huron. Over the years, pressure inside the pipeline, which is split into two separate pipes as it goes under the straits, has been increased so that it can move more oil.

If the pipeline starts leaking large amounts of petroleum, hundreds of miles of shorelines would be fouled and drinking water for thousands of people would be at risk. So would the commercial fishing, tourism and boating industries. Strong currents could spread the oil over a great distance.

Environmentalists warn that the damage could linger for decades in Lake Michigan and Lake Huron. In 2014, University of Michigan hydrodynamics expert David Schwab said the Straits of Mackinac is “the worst possible place for an oil spill in the Great Lakes.”

That’s a huge concern in a region that depends on its lakes. Regional officials should accelerate an existing investigation into the safety of the pipeline, and local authorities should start planning now — while they have time — for how they will ensure the safety of their communities if closure of the pipeline means more oil must be piped or transported by rail through the Chicago area, which already is home to major pipelines.

The Great Lakes region is an important North American hub for transporting and refining oil. The Enbridge pipeline is part of a 16,000-mile network that transports oil to 21 refineries, as well as natural gas and propane. If the line across the Straits of Mackinac is shut down, the nearly 23 million gallons of oil it moves each day — more than that planned for the controversial Dakota Access Pipeline — would have to be transported by other pipelines or by rail. Environmentalists say that can be managed with existing infrastructure.

Enbridge and the Illinois Petroleum Council say oil pipelines have an excellent safety record, and Enbridge says new safety measures it has put into place guard against a disastrous spill. But that’s what Enbridge said before one of its pipelines ruptured in 2010 in Michigan, dumping more than a million of gallons of oil into the Kalamazoo River. Even after three years of cleanup, oil remained in the river. Forgive us if we are skeptical.

An advisory board in Michigan, which has regulatory authority over the pipeline, is assessing the risks of the pipeline and weighing alternatives. A draft report is scheduled to be released this summer.

Clean energy may be America’s future. But transporting oil will remain an important part of the region’s economy in the foreseeable future. Officials should make the safety of the lakes paramount.

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