Enbridge Inc. won an environmental round in Michigan on Friday to keep its 540,000 b/d Line 5 oil pipeline running by securing state water permits to bury the pipe leg across the Straits of Mackinac.

The Michigan Department of Environment, Great Lakes and Energy (EGLE) approved the $500 million conduit. Regulators said “the proposed tunneling project would have minimal impact on water quality in the Great Lakes and would not affect protected public uses of Michigan’s water resources.”

Enbridge said the EGLE permits “are an important milestone for the tunnel project and are part of the process to authorize its construction.” Still needed are permit approvals from the Michigan Public Service Commission and the U.S. Army Corps of Engineers.

The Calgary-based pipeline...