Years of discussion, argument and litigation about how to deal with the aging Line 5 pipes under the Straits of Mackinac have left everyone involved with a bad taste in their mouths.

Michigan lawmakers during a December 2018 lame duck session approved an agreement with pipeline operator Enbridge. Some objected that the measure was poorly written and rushed to enactment before Democrat Gretchen Whitmer became governor a month later. Attorney General Dana Nessel issued an opinion in March 2019 that the authorizing bill was unconstitutional because its provisions exceeded what its title specified.

But unless another court battle ensues, last week’s ruling by the Michigan Court of Appeals — that legislators didn’t violate the state constitution — sets a clear path forward: Build a tunnel that will enclose a newer, safer pipeline.

The concept of a tunnel under the straits doesn’t please those who argue for the complete removal of the underwater portion of Line 5. Danger of a spill will remain, they say.

But the state appeals court has spoken. Enbridge says it plans to complete the tunnel by 2024. We hope the company can stay on schedule.

The old pipeline dates from around the time the polio vaccine was created and the Korean War ended. From soon after President Harry S. Truman authorized the seizure of U.S. steel mills to avert a strike — an action the U.S. Supreme Court quickly ruled illegal. From before anyone recognized the name Elvis Presley.

As we said in a May 2016 editorial: “Nothing lasts forever, and there is no reason to expect Line 5 is any different.”

Four years ago, we urged Gov. Rick Snyder to work with state experts and Enbridge officials to set a deadline for ending use of those aging pipes with damaged coatings and dents from anchor strikes. In 2016, we suggested the state provide a reasonable framework for the company to change its infrastructure and thereby lessen the danger of a toxic spill into Lake Michigan.

The court last week determined that the tunnel alternative can move forward. That decision provides the reasonable framework.

So let’s buckle on our work boots and get to it. We encourage the state and the company to proceed with safety, due diligence and speed.

In 2016, we suggested that a reasonable deadline be set to decommission the old pipeline.

Enbridge says it hopes to finish the tunnel by 2024, a couple of years shy of our 2016 10-year suggestion. Not all big construction projects come in on time, but we hope the old Line 5 pipes truly will be empty by 2024.

— Traverse City Record-Eagle