This coverage is made possible through a partnership with Grist and Interlochen Public Radio in Northern Michigan.

During a heated public meeting last Friday, Michigan’s top energy regulator granted the Canadian company Enbridge Energy a permit to build a new pipeline and tunnel under the environmentally sensitive Straits of Mackinac, in an important — but not final — step in the controversial project’s approval process.

Reader support makes our work possible. Donate today to keep our site free. All donations DOUBLED!

Construction can’t begin unless the U.S. Army Corps of Engineers grants it a federal permit. Before that happens, the Army Corps has to release its assessment of the project’s environmental impacts.

The Michigan Public Service Commission’s decision sparked strong reactions from opponents and supporters of the tunnel.

Grist thanks its sponsors. Become one.

Line 5 carries oil and natural gas liquids 645 miles from Superior, Wisconsin, to Sarnia, Ontario. Two pipelines run four miles along the lakebed, between lakes Huron and Michigan. Enbridge is proposing to replace those with a single 30-inch wide pipeline housed in a concrete tunnel in the bedrock below.

On Friday, the Public Service Commission said building the tunnel would meet the public’s energy needs while protecting that section of the pipeline from damage and preventing leaks.

Opponents called the decision “disastrous.”

The state has been in talks with Enbridge regarding the tunnel since 2017. 

Grist thanks its sponsors. Become one.

In 2018, an anchor struck the pipeline in the straits, damaging it. Commission Chair Dan Scripps cited that incident as an example of how vulnerable the pipes are, and why it was important to build this tunnel.

“We have a responsibility to approve the infrastructure needed to meet our energy needs, and to take steps necessary to get the current pipelines off the bottom lands,” he said.

Enbridge, which submitted a proposal for the tunnel in 2020, applauded the commission’s decision. Spokesperson Ryan Duffy said in an emailed statement on Friday that it is a “major step forward in making the Great Lakes Tunnel Project a reality.” 

State Senator John Damoose, a Harbor Springs Republican, was among the lawmakers cheering the decision; in a news release, he called it a “major development toward energy security in the region” and “tremendous news for residents of northern Michigan and the Upper Peninsula.”

But many people strongly oppose the tunnel and the pipeline.

The commission said it received more than 23,000 comments ahead of its decision, and people who spoke during Friday’s meeting said granting Enbridge a permit threatened their communities, their health, and the environment.

After the decision was announced, project opponents voiced their anger with the commission.

“You were supposed to protect the Great Lakes, protect us,” said Andrea Pierce, a citizen of the Little Traverse Bay Bands of Odawa Indians and chair of the Anishinaabek Caucus. “These pipelines and tunnels are going to go through my tribal lands, through my people’s lands, through my community. And I think that’s just reprehensible.”

All 12 federally recognized tribal nations in Michigan oppose Line 5. The Bay Mills Indian Community in the Upper Peninsula has been leading a legal fight to stop the tunnel project for years, citing threats to treaty rights, resources, and ways of life.

Bay Mills is challenging a separate tunnel permit from the state Environment, Great Lakes and Energy department.

“Today’s decision is another notch in a long history of ignoring the rights of tribal nations,” Bay Mills President Whitney Gravelle said in a statement. “We must act now to protect the peoples of the Great Lakes from an oil spill, to lead our communities out of the fossil fuel era, and to preserve the shared lands and waters in Michigan for all of us.”

Enbridge pipelines have ruptured multiple times. In what was one of the nation’s worst inland oil spills, a section of the Line 6B pipeline burst in 2010 and poured more than 840,000 gallons of oil into a tributary of the Kalamazoo River. (The Environmental Protection Agency estimated that 1.2 million gallons were recovered from the river in the following years.) 

In 2020, Governor Gretchen Whitmer ordered Enbridge to shut down Line 5 in the Straits of Mackinac by the spring of the following year, saying that Enbridge was violating its 1953 easement to operate there and that it threatened the Great Lakes with an oil spill. Enbridge defied that order. 

In addition to the threat of a spill, opponents say the project is a foe in the global fight against climate change.

The 70-year-old pipeline transports more than 22 million gallons of oil per day. Opponents of the tunnel project say this permit shows that the state will continue to rely on fossil fuels.

In 2021, the Michigan Public Service Commission agreed to consider greenhouse gas emissions when reviewing Enbridge’s tunnel proposal under the state’s Environmental Protection Act. 

It was the first time the commission considered climate impacts under the law when making its decision about a project like the pipeline. As part of that process, environmental groups submitted expert testimony to the commission.

Peter Erickson, then a climate policy director at the Stockholm Environment Institute, testified that construction of the tunnel would lead to the release of 27 million metric tons of carbon dioxide into the atmosphere annually, compared to a scenario where Line 5 was shut down and no tunnel was built. 

The commission said last week that it found no feasible alternatives to the tunnel project, and that many alternatives “would have a greater environmental impact.”

Commissioner Scripps acknowledged that a transition away from fossil fuels is taking place, mentioning the energy legislation recently signed into law by Whitmer, which requires that the state transition to 100 percent clean energy by 2040. Scripps said that in the meantime, the commission had a responsibility to approve infrastructure necessary to meet the state’s energy needs.

But there’s also disagreement on just how much Michigan relies on Line 5 for its energy. For instance, Enbridge says that the pipeline provides over half of Michigan’s propane, and that it’s central to energy security in the Upper Peninsula. But environmental groups like the Michigan League of Conservation Voters say there are alternatives. A report released in October by PLG Consulting said that with enough notice of a Line 5 shutdown, the state’s energy markets could adapt without supply shortages or price hikes.

While Friday’s decision by the commission was a big step toward the tunnel’s construction, it’s not the last.

Along with a slew of legal challenges, the U.S. Army Corps of Engineers will need to weigh in with its determination of the environmental impacts of the project. A decision on whether to grant the project a federal permit is expected in 2026.