CALGARY (Reuters) -The U.S. Army Corps of Engineers said on Friday it expects to make a decision this fall whether to grant a permit to Enbridge's ( ENB ) proposed Great Lakes tunnel for its Line 5 oil pipeline project.

The Army Corps, a federal engineering service, released an updated permitting timeline for the project that includes a 30-day public comment period from May 30 to June 3, followed by the decision in the fall.

The Army Corps has permitting authority over U.S. projects involving wetlands and waterways.

Last month, Enbridge's ( ENB ) Line 5 project received emergency designation after President Donald Trump declared a national energy emergency in a January executive order, giving the Army Corps the ability to fast-track its review of the project.

An Enbridge ( ENB ) spokesperson said in an email on Friday the company is encouraged by the updated schedule.

"Enbridge ( ENB ) submitted project permit applications for the Great Lakes Tunnel project to state and federal regulators in April 2020 - more than five years ago," the spokesperson said.

The project would build a roughly 4-mile (6-km) tunnel for the 645-mile Line 5 that crosses through the Straits of Mackinac in the Great Lakes. The pipeline carries more than 20 million gallons of oil and natural gas liquids daily from Superior, Wisconsin, to Sarnia, Ontario.

Michigan regulators had approved Enbridge's ( ENB ) application to build the $750-million tunnel under the Great Lakes to house its aging Line 5 oil pipeline in 2023, but the project still awaits Army Corps permitting.

Native American tribes and environmental groups who oppose the project because of the potential risk to the Great Lakes have refuted the idea that the tunnel is needed and that a national energy emergency exists.