FRESH NUTS, BOLTS and fittings are ready to be added to the east leg of the pipeline near St. Ignace, Mich., as Enbridge Inc., prepared in 2017 to test the east and west sides of the Line 5 pipeline under the Straits of Mackinac in Mackinaw City, Mich. A federal judge has ordered The Pipeline and Hazardous Materials Safety Administration to take a closer look at pipeline company Enbridge’s plans for dealing with a potential oil spill in the waterway connecting Lakes Huron and Michigan. (Dale G Young/Detroit News via AP, File)

TOLEDO, Ohio (AP) — Operators of refineries in Ohio are worried that a potential shutdown of a Great Lakes oil pipeline in Michigan could push up their costs or even force them to close.

Ohio Gov. Mike DeWine sent Michigan Gov. Gretchen Whitmer a letter this past week asking her to not let the pipeline in the Straits of Mackinac shut down permanently.

Michigan’s governor wants the company that owns the oil pipeline to finish its replacement within two years, but the company says it can’t be done until 2024.

Talks over the timeline broke down earlier this month.

Environmentalists are demanding an immediate shutdown because they say a rupture within the pipeline’s 4-mile-long underwater segment could contaminate hundreds of miles of Great Lakes waters and shorelines.

The pipeline known as Line 5 carries 23 million gallons (87 million liters) of crude oil and natural gas liquids daily.

Enbridge Inc. says the twin pipes that have been in place since 1953 are in sound condition and could operate indefinitely, but the company has said it’s willing to install a tunnel in bedrock 100 feet beneath the lakebed to eliminate virtually any possibility of a leak.

The pipeline is the source for much of the sweet crude used by the Toledo Refining Co. and there are no other no viable alternatives for the supply if the pipeline is taken out of service, according to PBF Energy, which owns the refinery.

“If Line 5 is shut down, it will jeopardize the continued operation of this facility,” Mike Gudgeon, PBF’s Toledo Refining manager, told The Blade.

The BP-Husky refinery in suburban Toledo and the Marathon Oil refinery in Detroit along with other refineries would be affected as well, the newspaper reported.

Jamal Kheiry, a spokesman for Marathon Petroleum Corp, has said more expensive methods of getting oil to its refinery would be necessary if the pipeline is shuttered.

Ohio’s Republican governor said both Ohio and Michigan could potentially lose more than 1,000 jobs.

He also wrote in his letter to Michigan’s governor, who is a Democrat, that Ohio’s two refineries near Toledo supply gasoline, diesel, and jet fuel to Ohio and southeast Michigan, including the majority of aviation fuels to Detroit Metro Airport.

“Our states have much at risk in terms of potential fuel price spikes, lost jobs, airline schedule disruptions and lost transportation project funding,” DeWine said.