Michigan Regulators Review Enbridge Line 5 Tunnel Permits Amid Governor’s Push for Shutdown
Michigan environmental regulators are re-examining permits for the Enbridge Line 5 tunnel project following a state Supreme Court ruling that raised environmental review standards. Governor Gretchen Whitmer has simultaneously urged Enbridge to shut down the existing pipeline within months, citing safety concerns and project delays.
State environmental regulators in Michigan have announced a review of recently granted permits for the Enbridge Line 5 tunnel project. The move follows a decision by the Michigan Supreme Court that heightened the standards required for environmental reviews. 
Governor Gretchen Whitmer and Phil Roos, director of the Michigan Department of Environment, Great Lakes and Energy (EGLE), confirmed the permit review on Wednesday. This announcement comes as Governor Whitmer wrote a letter to outgoing Enbridge CEO Gregory Ebel urging the company to shut down the existing Line 5 pipeline "within months." The governor cited safety concerns and significant delays in the construction of the planned tunnel beneath the Straits of Mackinac.
The controversy centers on legal and regulatory battles between the state and Enbridge. On July 31, the Michigan Supreme Court vacated a separate tunnel permit issued by the Michigan Public Service Commission, ruling that it had not adequately considered environmental impacts or alternatives. Prior to this, EGLE had issued key permits for the tunnel project on July 15, a decision that angered opponents who viewed it as a betrayal by Governor Whitmer.
Line 5 is a 73-year-old pipeline that transports up to 540,000 barrels a day of Canadian light oil, synthetic crude, and natural gas liquids from Superior, Wis., to Sarnia, Ont. It provides roughly 45 per cent of supplies for refineries in Detroit and Toledo, and meets 55 per cent of Michigan’s statewide propane needs. Enbridge has defied state orders to shut down the pipeline while awaiting permits for the new tunnel. 
Legal challenges continue to mount. US District Judge Robert Jonker ruled in Enbridge's favor in December regarding the state's authority to shut down the federally-regulated pipeline; the state appealed in January. Meanwhile, Attorney General Dana Nessel is seeking a shutdown in state court, but that case is paused pending the outcome of Enbridge’s federal legal battle. The Bay Mills Indian Community plans to appeal the EGLE permit, according to Earthjustice lawyer Debbie Chizewer.
The situation highlights deep divisions among stakeholders. Environmentalists and Native American tribes support the shutdown, viewing the tunnel as a tactic to divert attention from current risks. Conversely, unions and business groups advocate for the tunnel to ensure energy security and preserve jobs. Enbridge spokesperson Ryan Duffy lamented additional delays to a project originally targeted for completion in 2024, while Governor Whitmer argues the tunnel could be a decade away.