TRAVERSE CITY, Mich. (AP) — Building an oil pipeline tunnel beneath a channel linking two of the Great Lakes would risk environmental devastation, opponents said Monday, while supporters argued that rejecting the plan would further damage a Michigan economy already reeling from the coronavirus.

Both sides in a multi-year battle over the future of Enbridge's Line 5 faced off during an online public hearing before officials with the Army Corps of Engineers. The agency's Detroit district is considering whether to grant a permit for the project.

The Canadian pipeline company wants to drill a nearly 4-mile (6.4-kilometer) tunnel through bedrock under the Straits of Mackinac. It would house a replacement for twin pipes that have run along the bottom of the waterway connecting Lake Huron and Lake Michigan for 67 years.

The underwater segment is part of a line that carries crude oil and natural gas liquids used in propane between Superior, Wisconsin, and Sarnia, Ontario, passing through a lengthy stretch of northern Michigan.

Nearly 50 people spoke during the three-hour hearing, while others issued written statements. The Corps will accept comments through Dec. 17 but there's no deadline for its decision on the permit application, spokesman Bill Dowell said.

“Enbridge has a history of safety violations and environmental damage, and entrusting this serial bad actor to build a massive tunnel under our Great Lakes would be a mistake of epic proportions," said Beth Wallace of the National Wildlife Federation.

Mike Alaimo of the Michigan Chamber of Commerce responded that the $500 million project, which Enbridge has promised to pay for, would protect the lakes and bolster the regional economy while keeping energy prices affordable.

“As Michigan fights to recover from COVID-19, the jobs this project will create and support are more important than ever,” he said.

On Nov. 13, Michigan Gov. Gretchen Whitmer ordered Enbridge to shut down the pipeline within 180 days, saying the company had violated terms of an easement the state granted in 1953 to place the line on the lake bottom. Enbridge responded with a federal lawsuit and said it would ask the court to overrule the Democratic governor.

Army Corps officials said they were studying how Whitmer's order might affect their review of Enbridge's application for a permit under the federal Clean Water Act.

The company also needs a permit from the Michigan Department of Environment, Great Lakes and Energy, where an application is pending.