The Trump administration is stepping into the legal fight over whether Enbridge can continue to operate an aging pipeline beneath a Great Lakes channel, arguing that Michigan Gov. Gretchen Whitmer interfered with U.S. foreign policy when she revoked the line's easement almost five years ago.
The pipeline, known as Line 5, has moved crude oil between Superior, Wisconsin, and Sarnia, Ontario, since 1953. A 4.5-mile (6.4-kilometer) segment of the line runs under the Straits of Mackinac, a channel that
links Lake Michigan and Lake Huron.
Concerns about the line rupturing and causing a catastrophic spill in the environmentally sensitive area have been growing since 2017, when Enbridge revealed its engineers had known about gaps in its protective coating since 2014. A boat anchor damaged the segment a year later, further stoking fears of a spill.
Whitmer, a Democrat and possible 2028 presidential contender, ordered her regulators in November 2020 to revoke the easement allowing the segment to operate beneath the straits. Enbridge filed a federal lawsuit that same year seeking to invalidate the order. The pipeline has continued to operate as the litigation drags on.
The Trump administration isn't a party in the case. But U.S. Justice Department attorneys filed a brief on Sept. 12 arguing that Whitmer's order amounted to an attempt to “globalize” Michigan's regulatory authority and clash with the federal government's goal of maintaining the flow of energy between the U.S. and Canada.
They also contend that the revocation clashes with executive orders President Donald Trump issued this year declaring that an abundant, reliable energy supply is key to protecting national security.
“Shutting down Line 5 could disrupt the energy supply chain, increase domestic prices, and enhance the economic and political power and leverage of malign foreign actors worldwide,” the attorneys wrote. “Such outcomes conflict with our nation's foreign policy goals.”
They argue, too, that only the federal government can regulate pipeline safety and allowing states to enter that arena would lead to a untenable patchwork of regulations. A 1977 treaty between the U.S. and Canada prohibits authorities from impeding the flow of energy through pipelines running between the two counties, they add.
Whitmer's attorneys say the state has authority to revoke the easement under the public trust doctrine, the legal principle that natural resources belong to the public and the state therefore has a duty to protect them.
Danny Wimmer, a spokesperson for Michigan Attorney General Dana Nessel, who is defending the revocation, said in an email Friday that Nessel plans to file a response in October. He pointed to earlier filings in which she argues that revoking the easement doesn't impose or continue any safety regulations and is actually a pipeline routing decision within the state's authority. The filings also contend that private parties such as Enbridge can't bring a federal lawsuit to enforce the treaty with Canada.
The Trump administration's arguments largely mirror those of Enbridge. Asked for comment on the administration's filing, company spokesperson Michael Barnes in an email Friday pointed again to treaty provisions that he said prevent states and judges from unilaterally shutting down the pipeline.
U.S. District Judge Robert Jonker has scheduled a hearing on a Enbridge motion for summary judgment on Nov. 12.
Trump's decision to take a stance in the case is a setback for Whitmer as she tries to protect her state's interests without incurring the president's wrath. She has stepped lightly around Trump, convincing him to meet with her three times since January. In April, Trump called her a “very good person."
Enbridge has proposed encasing the straits segment in a protective concrete tunnel, at an estimated cost of at least $500 million. Construction would destroy wetlands and bat habitat but the tunnel would eliminate the chance of another anchor rupturing the line, according to the U.S. Army Corps of Engineers.
Michigan regulators approved permits for the tunnel in December 2023. Enbridge needs only Army Corps' approval before construction can begin. The Corps fast-tracked the permit in April after the Trump administration identified the tunnel for expedited emergency permitting.
Environmental groups and Native American tribes have sued the Michigan Public Service Commission, arguing the panel didn't consider the overall need for the pipeline when weighing whether to grant the tunnel permits. The Michigan Supreme Court announced Friday that it would hear the case.
Nessel filed her own lawsuit seeking to void the straits easement in 2019. The U.S. Supreme Court is weighing whether the case belongs in federal or state court.
The pipeline is at the center of a yet another legal dispute, this time in Wisconsin. A federal judge in Madison last summer gave Enbridge three years to shut down part of Line 5 that runs across the Bad River Band of Lake Superior’s reservation. The company has proposed rerouting the pipeline around the reservation and has appealed the shutdown order to the 7th U.S. Circuit Court of Appeals.
On a separate legal track, environmental groups and the Bad River Band have asked a judge to void state permits for the reroute. Hearings in that matter are scheduled to stretch into October.
