Michigan's environment department on Jan. 29 approved some of the permits needed for Canadian company Enbridge Inc. to build a tunnel to house its disputed oil pipeline under the Straits of Mackinac.

Enbridge's 68-year-old Line 5 pipeline carries 540,000 bbl/d of light crude and propane, and one 4.5-mile (7.2-km) section runs underwater along the lakebed.

Environmentalists concerned about the risk of a spill into the Great Lakes are trying to have the pipeline shut down, and Michigan Governor Gretchen Whitmer has revoked its easement, a move Enbridge is fighting in federal court.

The permits from Michigan's Department of Environment, Great Lakes and Energy (EGLE) is a step forward for Enbridge, but the Calgary, Alberta-based company still requires permits from the Michigan Public Service Commission and U.S. Army Corps of Engineers to move ahead with building the tunnel.

The permit decision on Friday also does not impact Whitmer's order to shut down Line 5 operations.

"Such a shutdown before the completion of the Great Lakes Tunnel Project would lead to major energy shortages in the region and severe economic consequences for Michigan, neighboring states and Canada," Enbridge spokesman Ryan Duffy said in a statement.

Oil pipeline opponents have been galvanized by new U.S. President Joe Biden issuing a raft of executive orders aimed at cutting greenhouse gas emissions, and revoking a key permit for the Keystone XL pipeline on his first day in office.

Environmental groups said they were disappointed by the Line 5 tunnel permit decision, but vowed to continue campaigning.

"The tunnel construction and the ongoing operation of the Line 5 pipeline will have devastating impacts all along its path throughout the Great Lakes," said Debbie Chizewer, managing attorney of Earthjustice. "We will continue to advocate...to bring attention to the dangers posed by this project and seek denial of the remaining permits needed."