Officials Report a Support Violation on Straits of Mackinac Oil Pipelines

Straits of Mackinac, by Louie Wannahocka (Own work) [CC BY-SA 4.0 (], via Wikimedia Commons

After inspections, officials reported Wednesday that Enbridge Energy Partners had violated a legal requirement by having too much unsupported space along its twin oil pipelines underneath a waterway that connects Lakes Michigan and Huron.

This problem is not new for Enbridge as it experienced the same issue two years ago with the pipelines in the Straits of Mackinac, after which the company said it took steps to ensure the violation would not happen again.

The affected pipelines are a part of Enbridge’s controversial Line 5, a 645-mile-long pipeline that runs crude oil and natural gas liquids between Superior, Wisconsin and Sarnia, Ontario.

Line 5 has been a heated issue for environmentalists and other communities who fear the pipeline poses a large risk to the Great Lakes. After the unsupported space violation was reported Wednesday, critics of the line believe the violation should serve as a wakeup call for the line’s termination.

Some sections of Line 5 rest directly on the lake bottom while others are raised and supported by steel anchors that are drilled into the lakebed. The state requires that no section of the pipelines longer than 75 feet be without support from either the lake bottom or an anchor. However, during an inspection in June, four locations were discovered to exceed the 75-feet limit by a foot or two, according to Enbridge spokesman Ryan Duffy.

“The Great Lakes is a dynamic environment and we anticipated that at times there can be changes to the lake bottom,” Duffy said. He also noted that the pipes were stable and the need for more supports did not signal a safety threat.

But because Enbridge experienced other unsupported spacing issues in 2014 that required the placement of 40 more anchors and a “predictive maintenance model” that would ensure the limit would not be exceeded again, officials have instructed the company to explain why its model failed and to come up with a better plan in the next two weeks.

Enbridge agreed to step up its inspections of Straits pipelines last month under a $176 million settlement with the federal government after the 2010 leak that spilled oil into the Kalamazoo River, resulting in the costliest inland oil spill in U.S. history.

The Seattle Times