One expert said he has reviewed documents submitted to the state for permitting of the Line 5 tunnel plan. Based on those documents, he said, the project should not move forward.
The Michigan-based geological engineer has done an analysis of tunnel proposals submitted to the state.
Brain O’Mara said he’s worked on tunnel projects across the country and is not against tunnel projects. But he said the Enbridge project just doesn’t add up.
“Enrbdige spent a lot of money out in the water and on the land doing an investigation,” O’Mara said. “The problem is it’s about 10-15% of what they should have done.”
O’Mara presented his analysis as part of a presentation put on by Oil and Water Don’t Mix, a group that opposes both the Line 5 tunnel project and the continued operation of the Line 5 pipeline.
The group said that O’Mara did not do his analysis at their request.
O’Mara said one of the problems is that the company took far fewer boring samples than it should have done. Normally, for a tunnel like the one proposed by Enbridge, boring samples should be taken every 50-200 feet for the length of the tunnel.
“If you add up their borings and they’ve got about 20 over 19,000 feet then they are averaging one per every 900 feet,” O’Mara said.
And he said, many of the initial assumptions made by the company around the design of the tunnel have proven false.
“They also assume very good ground, sound bedrock, minimal groundwater infiltration, and no geologic hazards,” he said. “None of those assumptions are valid.”
O’Mara said the state should send the plan back to Enbridge and request additional information.
“You’re never going to have 100% certainty but the more data they collect upfront the less they will be surprised by something. The last place you want to be surprised is out in the Straits of Mackinac.”
A spokesperson for Enbridge said the tunnel project is an engineering marvel that is “not only possible but will be a long term solution for environmental protection and energy security.”