Enbridge Inc. has scored fresh successes with its campaign to keep its 540,000 b/d dual-pipe Line 5 for oil and natural gas liquids by burying its disputed Straits of Mackinac crossing in a new utility tunnel.

After obtaining a permit from the Michigan Department of Environment, Great Lakes and Energy (MEGLE), the $500 million project has secured a ruling that shortened its review by the Michigan Public Service Commission (MPSC).

Administrative Law Judge (ALJ) Dennis Mack barred pipeline foes from stretching the case into a climate change policy debate over greenhouse gas emissions from Line 5 cargos if the 68-year-old pipeline from Canada continues to operate.

Mack rejected claims that the MPSC review must range beyond the Straits tunnel because Michigan Gov. Gretchen...