Advocacy News – Aug. 6, 2026
What’s happening: The Michigan Supreme Court set aside the Michigan Public Service Commission’s (MPSC) December 2023 approval of Enbridge’s proposed Great Lakes Tunnel project and sent the case back to the commission for additional review under the Michigan Environmental Protection Act. The ruling comes less than three weeks after state agencies issued separate permits for the project. Those permits remain in effect.
What the Court said: MSC concluded the commission should conduct additional analysis before approving the project, including whether construction of the tunnel would extend Line 5’s operating life, what additional environmental impacts could result from continued operation and whether the project and alternatives were evaluated using a consistent analytical framework.
Why it matters: Beyond Line 5, legal observers believe the decision could have broader precedent-setting implications for how major infrastructure projects are reviewed in Michigan. The Court’s interpretation may require more expansive environmental analysis during future permitting reviews, increasing timelines, regulatory complexity and uncertainty.
What we’re saying: The MPSC conducted a comprehensive, fact-based review before approving the project, relying on technical experts, years of analysis and extensive public input. The decision appears to discount years of work by both the commission and state and federal environmental agencies.
What’s next: The case now returns to the MPSC for further proceedings, although the timeline remains unclear.
Big picture: While the ruling requires additional review by the MPSC, it does not invalidate the separate permits recently issued by the Michigan Department of Environment, Great Lakes and Energy (EGLE) and Michigan Department of Natural Resources (DNR), nor does it affect the continued operation of Line 5.
The bottom line: The Michigan Chamber will continue advocating for construction of the Great Lakes Tunnel as the most environmentally protective solution for replacing the existing pipeline beneath the Straits. Beyond delaying this project, the decision could create greater uncertainty around Michigan’s regulatory environment and the predictability businesses and investors rely on when planning long-term infrastructure and energy investments.
Learn more: Read the court’s opinion, the Chamber’s statement or contact Mike Alaimo for Qs or more information.