
Beneath the Straits of Mackinaw lies the controversial Pipeline Number 5. Opponents claim the oil line threatens the largest freshwater system in the world. (Source: Shutterstock.com)
Enbridge won approval in December to replace a pipeline segment that runs under the Great Lakes, only to face swift legal challenges from two environmental groups.
The Environmental Law and Policy Center (ELPC) and the Michigan Climate Action Network filed an appeal against the decision by the Michigan Public Service Commission (MPSC) with the Michigan Court of Appeals on Dec. 22.
“One of the Commission’s primary responsibilities under Michigan law is to evaluate whether there are feasible and prudent alternatives to projects like this that will pose fewer environmental risks and cost less money,” Scott Strand, senior attorney at the ELPC, said in a Dec. 22 release. “But the Commission simply refused to consider the best alternative out there, which is simply to shut down the old Line 5 pipelines under the Straits and not replace them with a new pipeline at all.”
The Line 5 pipeline runs across the Mackinac Strait that separates Lake Michigan and Lake Huron. Line 5 is a twin pipeline with a capacity of 540,000 bbl/d that carries crude and NGL. Enbridge proposes to replace the two lines with a single line in a concrete tunnel below the lakebed.

Enbridge still needs approval from the U.S. Army Corps of Engineers to proceed. The company praised the Michigan Public Service Commission for the approval.
“Enbridge would like to thank everyone who provided public comment on the project. We are also grateful to the organizations that intervened in the MPSC approval process to advance the project, including the National and Michigan Propane Associations, and the Michigan Laborers’ District Council,” Enbridge spokesperson Ryan Duffy said in a statement. “The input from intervenors on both sides of the issue raised important questions that challenge us all to get this right.”
Line 5, built in 1953 supplies 55% of Michigan's statewide propane needs, according to Enbridge.
Recommended Reading
E&P Highlights: Feb. 3, 2025
2025-02-03 - Here’s a roundup of the latest E&P headlines, from a forecast of rising global land rig activity to new contracts.
Chevron Completes Farm-In Offshore Namibia
2025-02-11 - Chevron now has operatorship and 80% participating interest in Petroleum Exploration License 82 offshore Namibia.
E&P Highlights: March 24, 2025
2025-03-24 - Here’s a roundup of the latest E&P headlines, from an oil find in western Hungary to new gas exploration licenses offshore Israel.
EOG Ramps Gassy Dorado, Oily Utica, Slows Delaware, Eagle Ford D&C
2025-03-16 - EOG Resources will scale back on Delaware Basin and Eagle Ford drilling and completions in 2025.
ADNOC Contracts Flowserve to Supply Tech for CCS, EOR Project
2025-01-14 - Abu Dhabi National Oil Co. has contracted Flowserve Corp. for the supply of dry gas seal systems for EOR and a carbon capture project at its Habshan facility in the Middle East.
Comments
Add new comment
This conversation is moderated according to Hart Energy community rules. Please read the rules before joining the discussion. If you’re experiencing any technical problems, please contact our customer care team.