An advancement in safety, and a $500-million investment in Michigan

Line 5 Straits tunnel project demonstrates Enbridge’s commitment to protecting the Great Lakes


We’re enhancing safety. We’re replacing energy infrastructure. And we’re investing in Michigan.

Today, Enbridge announced that we’ve reached an agreement with the Mackinac Straits Corridor Authority (MSCA) on the future of our Line 5 light oil and natural gas liquids (NGL) pipeline.

We’ll be making a safe pipeline safer—by replacing our Line 5 Straits of Mackinac crossing with a pipeline secured in a larger tunnel, bored deep beneath the lakebed.

The tunnel project represents a private investment of about $500 million in Michigan by Enbridge, with no taxpayer dollars involved. It will entail a geotechnical and engineering analysis in 2019, followed by design and construction, placement into service, and decommissioning of the current dual pipelines anchored to the bottom of the Straits. The targeted completion date is 2024.

While Line 5 has operated safely at the Straits for 65 years, we’re enhancing safety where it matters most. This tunnel would protect the aquatic environment, and reduce the likelihood of environmental impact to near zero.

We’re also continuing to safely deliver the energy Michigan needs. More than 300,000 Michigan families use propane to heat their homes, and Line 5 meets more than half of those propane needs—every single day.

This major infrastructure project is an investment in Michigan,” says Brad Shamla, Enbridge’s Vice President of U.S. Liquids Pipelines operations. “It will deliver long-term environmental protection, as well as energy security, jobs and opportunities for the people of Michigan.”

Enbridge also announced today a third agreement with the State of Michigan that puts in place enhanced inspection and operations protocols for the current Line 5. These important steps will ensure that the current Line 5 dual pipelines will continue to be operated safely while a tunnel is built.

In addition, Enbridge has committed to providing funding for cameras to give the U.S. Coast Guard real-time monitoring capabilities for Straits shipping traffic. This added safety measure provides further assurance for the dual pipelines at the Straits until the new tunnel is in operation.

This Line 5 tunnel project has benefited from the expertise of qualified engineering, construction and environmental consultants, as well as State-appointed independent experts.

Multiple layers of protection—including a thick, reinforced concrete liner and a depth of as much as 100 feet beneath the lakebed—render the chances of a leak into the Great Lakes virtually zero, and eliminate the possibility of anchor strikes.

All work will take place underground, and will not disturb the lakebed, fish or wildlife.

“Line 5 is an important part of Michigan’s energy infrastructure,” adds Mr. Shamla, “and placing a new tunnel under the Straits will eliminate potential risks—while ensuring a reliable and affordable energy supply to both the Upper and Lower Peninsulas.”