Background
Enbridge Energy Limited Partnership sought approval from the Michigan Public Service Commission to replace the portion of its Line 5 pipeline crossing the Straits of Mackinac. The proposed project would decommission the existing dual pipelines and place a new 30-inch pipeline inside a concrete-lined tunnel beneath the lakebed.
Indian Tribes and environmental organizations intervened in opposition. The PSC approved the project under Act 16 and concluded that it satisfied the Michigan Environmental Protection Act, but limited much of its environmental review to the replacement segment and tunnel. It also declined to consider the public trust doctrine. The Court of Appeals affirmed the PSC in a published per curiam opinion.
The Court’s Holding
The Michigan Supreme Court held that courts must review an agency’s application of MEPA de novo, independently examining the legal issues and record without deferring to the agency’s MEPA determination. The Court held that MEPA requires consideration of environmental harms factually and proximately caused by the proposed conduct, a fair comparison between the environmental effects of that conduct and its alternatives, and separate consideration of effects on public trust resources.
Applying those rules, the Court concluded that the PSC should have determined whether the tunnel project would factually and proximately extend Line 5’s operational life and thereby cause additional environmental harm. The PSC also used inconsistent scopes when comparing the project with alternatives and failed to determine whether the project would pollute, impair, or destroy public trust resources. The Court reversed the Court of Appeals, vacated the PSC’s approval order, and remanded to the PSC for further proceedings. Justice Brian K. Zahra agreed that the PSC must expressly address the public trust but otherwise dissented.
Key Takeaways
- Judicial review of an agency’s MEPA determination is de novo, even when the matter began as an administrative proceeding.
- MEPA reaches environmental harms beyond the immediate project only when factual and proximate causation make them likely effects of the challenged conduct.
- The PSC must determine whether the tunnel would extend Line 5’s operating life, compare the project and alternatives on a consistent environmental basis, and assess harm to Great Lakes public trust resources.
Why It Matters
The decision vacates Enbridge’s existing PSC approval rather than finally prohibiting the tunnel. On remand, the PSC must conduct the broader and more internally consistent MEPA analysis required by the Court before deciding whether the project may be approved.
More broadly, the ruling establishes a nondeferential standard for judicial review of agency MEPA decisions and confirms that Michigan environmental review must account for causally connected downstream harms and the public’s protected interests in the Great Lakes and their submerged lands.