The Calgary-based company is proposing to build a roughly 4-mile (6-km) tunnel for the pipeline, which crosses through the Straits of Mackinac in the Great Lakes.
The project faces opposition from Native American tribes and environmental groups, who fear it poses a risk to the Great Lakes.
Enbridge said in a statement that it remains confident in the Michigan Public Service Commission’s permitting process, which approved the tunnel project.
(Reporting by Amanda Stephenson in Calgary and Ismail Shakil in Ottawa; Editing by Lisa Shumaker)