Members of the public attend a hearing over Enbridge Line 5. (Photo courtesy of Devon Young Cupery)

An administrative law judge in Madison heard arguments Wednesday in a case contesting Wisconsin’s approval of Enbridge’s proposed Line 5 pipeline reroute. Members of the  public testified, followed by an expert witness in geology and hydrology, who questioned aspects of the reroute plan. 

The lawsuit, brought by Clean Wisconsin and Midwest Environmental Advocates (on behalf of the Sierra Club of Wisconsin, the League of Woman Voters of Wisconsin and 350 Wisconsin), challenges permits allowing the Canadian oil company to move forward with rerouting the Line 5 pipeline around the Bad River reservation in northern Wisconsin. Wednesday’s hearing followed the opening day of testimony in Ashland and was one of a series of hearings  scheduled through early October. The Bad River Band of Lake Superior Chippewa is challenging Wisconsin Department of Natural Resources permits for a Line 5 reroute, which was designed to fix a legal problem with the existing pipeline after a federal court found that it trespasses on tribal land. Attorneys for the Band, environmental groups and Enbridge testified at the hearing. 

Enbridge’s Line 5 pipeline has been a polarizing issue, with one side arguing that it’s crucial for energy independence and jobs in Wisconsin, while the other points to a history of leaky and ruptured Enbridge pipelines causing ecological damage, a national need to transition away from fossil fuels, and the company’s years-long trespass on the Bad River Band’s sovereign land. 

Public testimony Wednesday drew  people from both sides of the debate. “The loss of Line 5 would have devastating impacts on the propane industry,” said Connor Kaeb, an associate manager with GROWMARK, which Kaeb said is Wisconsin’s fifth largest provider of propane. Kaeb stressed that farmers and northern Wisconsin communities depend on affordable and easily accessible propane. Shutting down Line 5 could cause “immense strain on the entire propane system in the region,” he said. 

Tabitha Faber, who spoke against the pipeline, said that the reroute would cross more than 100 waterways, and that even though it avoids the Bad River Band’s reservation, that the pipeline remains in the Bad River watershed, continuing to endanger the Band’s natural resources. Faber recalled visiting sites along the reroute path and seeing bald eagles and wood turtle  habitats. Faber also said that the pipeline’s construction and operation could wash invasive species into new and sensitive habitats, including within the Bad River reservation. Steve Boas, a Madison resident, also spoke against the project, calling the more than 70-year-old pipeline “an accident waiting to happen.” 

The American Petroleum Institute called the relocation project “essential to maintaining Wisconsin’s energy reliability.” The Institute claimed that rerouting Line 5 will create more than 700 jobs, adding that the pipeline has heated homes and businesses, aided agriculture and enabled transportation for decades “without any issue.” In contrast, Third Act Wisconsin — a group of older Americans concerned about climate and democracy — echoed concerns that Line 5 would threaten high-quality wetlands, the Bad River watershed as a whole and even Lake Superior.

Access to clean water is a crucial asset for Wisconsin, environmental groups testified. Tourism generates $378 million in Bayfield, Ashland, Douglas, and Iron counties, while also supporting 2,846 jobs, all in the area near Line 5, according to Clean Wisconsin. 

“For decades, the Bad River Band has been sounding the alarm about the unprecedented risks posed by Enbridge’s Line 5 pipeline,” Ellen Ferwerda, who leads Third Act Wisconsin’s work on Line 5, said in a statement. Despite “a myriad of scientists, economists, environmental groups, and citizens” who’ve spoken out against the pipeline, “the DNR summarily dismissed these concerns and issued a permit allowing Enbridge to begin construction of a reroute around the Bad River Reservation.” 

“It feels like the Bad River Band is being punished for standing up for their legal right to protect the watershed their culture and livelihood has relied on for centuries,” she added. Julia Issacs, co-facilitator of Third Act Wisconsin, said in a statement that “we should be decommissioning old and dangerous pipelines, not investing in new fossil fuel infrastructure.” 

Most of Wednesday’s hearing was dedicated to grilling William Joseph Bonin, a licensed senior geologist with Midwest Geological Consultants. He produced a report in May 2025 that pushed back on assessments made by experts from the DNR and Enbridge. 

Bonin raised a multitude of concerns, particularly around how construction of the pipeline could affect springs, aquifers and groundwater. He pointed to the presence of glacial sediments, which make it difficult to predict how water flow could be affected. Bonin recalled one 2018 project in Minnesota, where a gas pipeline was installed along a roadway near adjacent springs. The springs disappeared, and then other springs showed up in a parking lot on a private property, he said. Springs and aquifers that help feed nearby wetlands and other adjacent habitats could be affected by pipeline construction, he testified, and cutting trenches to construct the pipeline could also lead to increased erosion.

Bonin said the risk of aquifer breaches is higher than what had been assessed, and questioned how the presence of already fractured rock layers could be altered by the use of blasting in constructing the reroute. He also pointed to the possibility of “thermal impacts” to waterways, including high-quality trout streams which are sensitive to temperature changes. “Blasting is going to have a larger impact than the expert reports discussed and the reason for that is the already fractured bedrock was not taken into consideration in the reports,” Bonin said. “The effects of blasts, especially on fracture networks, may be permanent,” he added.  “The basted rock is never going to be restored.” This, in turn, could have a ripple effect on how water moves and behaves in the ground around the pipeline reroute, he testified. 

Attorneys representing the DNR and Enbridge took turns cross-examining Bonin. They discussed knowledge gaps Bonin had regarding the wetland aspects of the permits, and argued that methods like blasting and trenching are very common construction practices for all sorts of projects from pipelines to roads.  Enbridge’s attorney pointed out that, while  Bonin has reviewed and analyzed the effects of blasting, Bonin himself has not worked in the field. 

Another hearing in Madison is scheduled for Friday, Sept. 12, at the Hill Farms State Office Building. On Sept. 15 and 19, there will be  hearings in Ashland at the Northwood Technical College Conference Center, followed by more hearings in Madison on Sept. 22, Sept. 26, Sept. 29 and Oct. 3. 

Building an underground tunnel for an aging Enbridge oil pipeline that stretches across a Great Lakes channel could destroy wetlands and harm bat habitats but would eliminate the chances of a boat anchor rupturing the line and causing a catastrophic spill, the U.S. Army Corps of Engineers said Friday in a long-awaited draft analysis of the proposed project’s environmental impacts.

The analysis moves the corps a step closer to approving the tunnel for Line 5 in the Straits of Mackinac. The tunnel was proposed in 2018 at a cost of $500 million but has been bogged down by legal challenges. The corps fast-tracked the project in April after President Donald Trump ordered federal agencies in January to identify energy projects for expedited emergency permitting.

A final environmental assessment is expected by autumn, with a permitting decision to follow later this year. The agency initially planned to issue a permitting decision in early 2026.

With that permit in hand, Enbridge would only need permission from the Michigan Department of Environment, Great Lakes and Energy before it could begin constructing the tunnel. That’s far from a given, though.

Environmentalists have been pressuring the state to deny the permit. Meanwhile, Michigan Attorney General Dana Nessel and Gov. Gretchen Whitmer are trying to win court rulings that would force Enbridge to remove the existing pipeline from the straits for good.

Construction could have major short-term, long-term impacts

The analysis notes that the tunnel would eliminate the risk of a boat anchor rupturing the pipeline and causing a spill in the straits, a key concern for environmentalists. But the construction would have sweeping effects on everything from recreation to wildlife.

Many of the impacts, such as noise, vistas marred by 400-foot (121-meter) cranes, construction lights degrading stargazing opportunities at Headlands International Dark Sky Park and vibrations that would disturb aquatic wildlife would end when the work is completed, the report found.

Other impacts would last longer, including the loss of wetlands and vegetation on both sides of the strait that connects Lake Huron and Lake Michigan, and the loss of nearly 300 trees that the northern long-eared bat and tricolored bat use to roost. Grading and excavation also could disturb or destroy archaeological sites.

The tunnel-boring machine could cause vibrations that could shift the area’s geology. Soil in the construction area could become contaminated and nearly 200 truck trips daily during the six-year construction period would degrade area roads, the analysis found. Gas mixing with water seeping into the tunnel could result in an explosion, but the analysis notes that Enbridge plans to install fans to properly ventilate the tunnel during excavation.

Enbridge has pledged to comply with all safety standards, replant vegetation where possible and contain erosion, the analysis noted. The company also has said it would try to limit the loudest work to daytime hours as much as possible, and offset harm to wetlands and protected species by buying credits through mitigation banks. That money can then be used to fund restoration in other areas.

“Our goal is to have the smallest possible environmental footprint,” Enbridge officials said in a statement.

The Sierra Club issued a statement Friday saying the tunnel remains “an existential threat.”

“Chances of an oil spill in the Great Lakes — our most valuable freshwater resource — skyrockets if this tunnel is built in the Straits,” the group said. “We can’t drink oil. We can’t fish or swim in oil.”

Julie Goodwin, a senior attorney with Earthjustice, an environmental law group that opposes the project, said the corps failed to consider the impacts of a spill that could still happen on either side of the straits or stopping the flow of oil through the Great Lakes.

“My key takeaways are the Army corps has put blinders are in service to Enbridge and President Trump’s fossil fuel agenda,” she said.

Tunnel would protect portion of Line 5 running through straits

Enbridge has been using the Line 5 pipeline to transport crude oil and natural gas liquids between Superior, Wisconsin, and Sarnia, Ontario, since 1953. Roughly 4 miles of the pipeline runs along the bottom of the Straits of Mackinac.

Concerns about the aging pipeline rupturing and causing a potentially disastrous spill in the straits have been building over the last decade. Those fears intensified in 2018 when an anchor damaged the line.

Enbridge contends that the line remains structurally sound, but it struck a deal with then-Michigan Gov. Rick Snyder’s administration in 2018 that calls for the company to replace the straits portion of the line with a new section that would be encased in a protective underground tunnel.

Enbridge and environmentalists spar in court battles

Environmentalists, Native American tribes and Democrats have been fighting in court for years to stop the tunnel and force Enbridge to remove the existing pipeline from the straits. They’ve had little success so far.

A Michigan appellate court in February validated the state Public Service Commission’s permits for the tunnel. Nessel sued in 2019 seeking to void the easement that allows Line 5 to run through the straits. That case is still pending. Whitmer revoked the easement in 2020, but Enbridge challenged that decision and a federal appellate court in April ruled that the case can proceed.

Another legal fight over Line 5 in Wisconsin

About 12 miles (19 kilometers) of Line 5 runs across the Bad River Band of Lake Superior Chippewa’s reservation in northern Wisconsin. That tribe sued in 2019 to force Enbridge to remove the line from the reservation, arguing it’s prone to spilling and that easements allowing it to operate on the reservation expired in 2013.

Enbridge has proposed a 41-mile (66-kilometer) reroute around the reservation. The tribe has filed a lawsuit seeking to void state construction permits for the project and has joined several other groups in challenging the permits through the state’s contested case process.

Army Corps analysis: Great Lakes pipeline tunnel would have sweeping environmental impacts is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.