Pipelines are gaining more of the public’s attention these days, from President Obama’s rejection of the proposed Keystone XL pipeline to the concerns many Ohio property owners have expressed over how the new era of shale fracking is creating bigger demands to move natural gas through their state.

But one of the Great Lakes region’s biggest pipeline battles is over a line that has been used to move oil under the highly sensitive Straits of Mackinac since 1953 with hardly anyone noticing.

Enbridge Line 5 is a 645-mile, 30-inch-diameter pipeline running from Superior, Wis., to Sarnia, Ont.

It’s the five-mile stretch between Michigan’s Upper and Lower Peninsulas that garners the most attention. A spill or rupture there could ruin millions of gallons of fresh water in lakes Michigan and Huron.

The controversy was one of the issues addressed Friday at the University of Toledo College of Law’s 15th annual Great Lakes Water Conference.

“Since the Kalamazoo River spill, pipelines have gotten more and more scrutiny,” Noah Hall, a Wayne State University law professor and the panel’s moderator, said to open discussion.

He said the movement of fossil fuels has become a bigger environmental issue, especially in the industry-heavy Great Lakes region.

“Pipelines are, in many ways, the issue of the day,” Mr. Hall said.

The Kalamazoo River oil spill occurred in 2010, the same year as BP’s much higher-profile Deepwater Horizon spill in the Gulf of Mexico. The latter was the largest spill in U.S. history; the Kalamazoo River oil spill was the largest to ever affect an inland U.S. river.

Enbridge also owns the pipeline that spilled into the Kalamazoo near Marshall, Mich., about a two-hour drive northwest of Toledo. 

Though the company was cited by federal regulators for waiting too long to report the Kalamazoo spill, Enbridge said it has “paid special attention to the Straits of Mackinac,” has never had a leak there, and is “working hard” to ensure it never does.

“While the likelihood of a leak in the Straits is low, we’re well aware of the environmental sensitivity of the area; we know the consequences would be significant,” according to a statement on Enbridge’s website.

The company did not have a representative at UT’s event. A Marathon lawyer on the panel, though, said the pipeline industry acts responsibly and avoiding leaks and spills is in its own best interest.

“Everything that’s in a pipeline is a commodity,” said Greg Smith, a Marathon senior counsel. “It’s not something we want to spill from a business standpoint and it’s certainly not something we want to spill from a health, environmental, or safety standpoint.”

Enbridge Line 5 remains controversial, though, especially after the company received authorization two years ago to expand its operations and send 540,000 barrels of oil per day through it. Its original daily volume was 300,000 barrels.

Another panelist, Carl Weimer, is executive director of the Pipeline Safety Trust, based in Washington state. It was created in response to a 1999 fireball in the Seattle suburb of Bellingham, Wash., that killed an 18-year-old and two 10-year-olds. Problems with a pipeline there resulted in a massive explosion, national pipeline reform in Congress, and the largest fine of its kind in history.

“Pipeline safety is like a three-legged stool,” Mr. Weimer said. “Pipelines are out of sight, out of mind. People often don’t pay attention until something goes wrong.”

Using data from the national pipeline mapping system, he learned 15 hazardous waste pipelines cross the Maumee River, not known to many people.

Federal records, he said, showed a pipeline’s age does not always correlate to its safety.

While those built in the 1920s are more prone to corrosion and breakdown now, leaks are more common among newer pipelines than those installed during the 1950s, 1960s, and 1970s, according to data Mr. Weimer presented.

“When you’re talking about the Great Lakes, there’s a tipping point where it becomes an unacceptable risk,” said another panelist, Liz Kirkwood, executive director of the Traverse City-based environmental group, FLOW.

Michigan Attorney General Bill Schuette told several Michigan news organizations over the summer that alternatives should be studied and that Enbridge Line 5’s days “are numbered.”

“It’s a linchpin about what to do with this pipeline,” Ms. Kirkwood told the UT audience. “I don’t know if you could ever assure it will never rupture. What the Great Lakes brings to this region and to the planet is immeasurable.”

Contact Tom Henry at: thenry@theblade.com, 419-724-6079, or via Twitter @ecowriterohio.

First Published November 9, 2015, 5:00 a.m.