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 two existing pipelines on or above the lakebed and install a new pipeline inside a concrete-lined tunnel beneath the Straits.
Tribal nations and environmental organizations opposed the project, challenging the scope of the Commission’s review under the Michigan Environmental Protection Act. The Commission approved the project after limiting much of its analysis to the replacement segment and tunnel, finding no feasible and prudent alternative, and declining to consider the public trust doctrine. The Michigan Court of Appeals affirmed.
The Court’s Holding
The Michigan Supreme Court held that courts must review an agency’s application of the Michigan Environmental Protection Act de novo. The reviewing court must independently consider the legal issues and the administrative record rather than defer to the agency’s environmental determination.
The Court further held that the Act 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. The Commission therefore had to determine whether the replacement project would extend Line 5’s operational life and thereby cause additional environmental harms; it also erred by using inconsistent scopes when comparing the project with alternatives and by failing to assess harm to public trust resources in the Great Lakes. The Court reversed the Court of Appeals, vacated the Commission’s approval order, and remanded for further proceedings without deciding whether the project ultimately should be approved.
Key Takeaways
- Agency determinations under the Michigan Environmental Protection Act receive de novo judicial review.
- Environmental review extends to harms that are factually and proximately caused by the proposed conduct, which may include harms associated with extending an existing facility’s operational life.
- The agency must compare the environmental impacts of the proposal and its alternatives on a consistent basis and separately evaluate potential harm to public trust resources.
Why It Matters
The decision clarifies that Michigan agencies and reviewing courts cannot confine environmental analysis to a project’s immediate physical footprint when the project may proximately cause broader harms. It also establishes that an agency’s expertise does not entitle its application of the state environmental statute to deferential judicial review.
For the Line 5 tunnel, the ruling reopens the approval process and requires the Commission to conduct the analysis the Court found missing. It does not itself prohibit construction or determine that continued operation of Line 5 will cause the asserted harms.