TRAVERSE CITY, Mich. (AP) — Gov. Gretchen Whitmer established a panel Friday to assess energy needs in Michigan’s Upper Peninsula amid a dispute with the company whose pipeline plays a key role in supplying the region with propane.

Among the task force’s jobs will be finding ways to get propane for the far-flung peninsula that don’t involve Enbridge Inc.’s Line 5, which transports natural gas liquids used in the fuel, in addition to crude oil. The pipeline extends 645 miles (1,038 kilometers) between Superior, Wisconsin, and Sarnia, Ontario, crossing a large section of the Upper Peninsula.

A 4-mile (6.4-kilometer) segment divides into two pipes beneath the Straits of Mackinac, a channel that connects Lakes Huron and Michigan. That underwater section is the focus of a lengthy debate that boiled over this week as talks between Enbridge and Whitmer’s administration over replacing it appeared to break down.

“Enbridge has a disappointing safety record in Michigan, and the dual pipelines that run through the Straits of Mackinac create an unacceptable risk of an oil spill by anchor strike or other means,” Whitmer said. “Such an event would be catastrophic for the Great Lakes and our economy, and would send energy costs skyrocketing for U.P. families.”

About 25% of the peninsula’s residents use propane for home heating and much of it is delivered through Line 5, she said. Enbridge says Line 5 delivers 65% of the U.P.’s propane and 55% of the propane used statewide.

The Canadian company has emphasized the pipeline’s function as a carrier of the fuel in its battle against environmental groups pushing to shut it down.

Enbridge contends the 66-year-old pipeline is in good condition but has offered to replace the underwater section with a new pipe that would be housed in a tunnel beneath the straits. The company pledges to cover the $500 million cost and complete the project by early 2024.

Whitmer wants the underwater segment shut down even sooner. Enbridge says it can’t move any faster and won’t decommission the existing pipes before the new one is ready.

The company filed a lawsuit Thursday, asking the Michigan Court of Claims to rule on the legality of a tunnel construction deal it struck last year with former Republican Gov. Rick Snyder. Whitmer, a Democrat, has refused to carry out the agreement since Attorney General Dana Nessel said legislation authorizing it violated the state constitution.

Enbridge said Friday the tunnel “is the best long-term opportunity to secure the energy needs of the state while making an already safe pipeline even safer.”

A state-commissioned report in 2017 found there is “no viable way of moving the products transported by Line 5 on our other pipelines, competitor pipelines or by rail or truck,” the company said.

The National Wildlife Federation countered that other economic studies had found a Line 5 shutdown would have little if any effect on energy costs.

Whitmer said the “unacceptable threat” of an oil spill and the lack of a backup plan to distribute propane if Line 5 were to malfunction made it essential to find alternatives.

The task force also will look at other energy challenges in the Upper Peninsula, which has some of the nation’s highest electricity costs. It will make recommendations “that ensure the U.P.’s energy needs are met in a manner that is reliable, affordable and environmentally sound,” Whitmer said.

The 13-member panel will submit a report on propane supply alternatives by March 31, 2020, and a broader version on meeting U.P. energy needs a year later.