Background
Enbridge Energy sought approval from the Michigan Public Service Commission to replace the two Line 5 pipelines crossing the Straits of Mackinac with a new pipeline housed in a concrete-lined tunnel beneath the lakebed. Several Indian Tribes and environmental organizations intervened in opposition, while industry and labor groups supported the project.
The PSC approved the project under Michigan’s pipeline law and the Michigan Environmental Protection Act, generally limiting its environmental review to the replacement segment and tunnel. It declined to determine whether the project would extend Line 5’s operational life and cause related environmental harm, and it did not separately analyze effects on public-trust resources. The Court of Appeals affirmed the approval.
The Court’s Holding
In a six-justice majority opinion, the Michigan Supreme Court held that courts must review an agency’s application of MEPA de novo. It further 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 potential harm to public-trust resources.
The majority concluded that the PSC failed to determine whether the tunnel project would factually and proximately extend Line 5’s operational life and thereby cause additional environmental harm. It also held that the PSC used inconsistent scopes when comparing the project with alternatives and failed to assess effects on the public trust. The Court reversed the Court of Appeals, vacated the PSC’s approval order, and remanded for further proceedings.
Justice Brian K. Zahra concurred only in the need to remand for express findings concerning the public trust and otherwise dissented. He rejected the majority’s de novo standard of review, its requirement that the PSC examine whether the project would prolong Line 5’s operation and cause attendant harms, and its treatment of the alternatives analysis.
Key Takeaways
- Judicial review of an agency’s application of MEPA is de novo, according to the six-justice majority.
- The PSC must determine whether the replacement project would factually and proximately extend Line 5’s lifespan and cause additional environmental harm.
- MEPA requires consistent environmental comparisons of the proposed conduct and its alternatives, along with separate analysis of harm to public-trust resources.
Why It Matters
The decision requires Michigan agencies conducting MEPA reviews to examine environmental consequences extending beyond a project’s immediate physical footprint when those consequences may be factually and proximately caused by the project. It also subjects agency MEPA determinations to independent judicial review rather than deferential review.
The ruling does not finally reject the Line 5 tunnel. It vacates the existing approval and requires the PSC to reconsider the project under the majority’s causation, alternatives, and public-trust framework.