Line 5 Frequently Asked Questions

Q: What is Enbridge doing to protect the Straits? (Video)

A dedicated team monitors the line constantly. Enbridge also conducts internal inspections via a MRI-like tool known as a “pig” that travels the line recording data on the pipe’s thickness and looking for cracks, dents or signs of corrosion. We keep an eye on the outside of the pipeline with the help of divers and, in partnership with Michigan Tech, use an underwater autonomous vehicle to visually inspect the line. We perform external inspections twice as often as federal pipeline regulations require.

Watch the Q&A video: How do we monitor Line 5 and keep it operating safely?

Q: How was Line 5 built to be safe? (Video)

Line 5 was built to last. In 1953, Enbridge's Line 5 Straits of Mackinac crossing was built to extraordinary standards, using the finest engineering expertise from across the United States. The twin pipelines under the Straits have not experienced any leaks in six decades of operation – a testament to their design, construction, and maintenance regimen. Line 5 was built for an underwater environment, and still exceeds today's standards for pipeline safety.

Watch the Q&A video: How was Line 5 built to be safe?

Q: How is Line 5 inspected? Is the pipeline deteriorating? (Video)

Line 5 was built for the underwater environment, with nearly one-inch-thick steel walls and fiber-reinforced enamel coating. It was built by Merritt-Chapman & Scott, the same company that built the Mackinac Bridge, using the same kind of steel. Like the bridge, the intention has always been to operate and maintain it carefully to maximize its lifespan. Recent inspection reports show that Line 5, from an engineering and integrity perspective, is like new and in excellent condition.

Watch the Q&A video: How do we inspect Line 5?

Q: Is Line 5 aging, and too old? (Video)
Q: Enbridge is an oil giant that doesn’t care about Michigan and just wants to make money.

Safety is one of our core values. The people who live near our pipelines expect us to operate safely, and the protection of the public and the environment is our highest priority. More than 250 Michigan residents are employed or contracted with Enbridge, and they all play an important role in maintaining the safety and reliability of our pipelines and facilities.

Q: Enbridge is the same company that caused a giant spill in Marshall. Why would this be any different? (Video)

We regret the spill in the summer of 2010 that caused oil to flow into the Kalamazoo River. Those were the darkest days in our company’s history and we will never forget the lessons of Marshall. Since then, Enbridge has transformed its approach to safety, investing heavily in enhanced monitoring, safer pipelines, and more staff to keep operations safe.


We learned some very tough lessons through the Marshall incident – lessons that have, ultimately, made us a safer company. We made a promise to the people of Marshall and Battle Creek; we accepted responsibility; we have and continue to honor our commitment to completing the remediation of the Kalamazoo River.

Watch the video: A river returns to its people

Q: Will Line 5 be used to transport heavy crude oil?

Line 5 carries light crude oil and natural gas liquids, which power manufacturing, heat homes and fuel our cars. It does not carry, and has never carried, heavy crude oil.

Q: How is Line 5 important to Michigan? (Video)
Q: Line 5 transports products that benefit other states or countries. Does it benefit Michigan?

As of June 2016, Line 5 supplies 65% of propane demand in the Upper Peninsula, and 55% of Michigan's statewide propane needs. Line 5 also transports roughly 14,000 barrels per day of crude oil produced in Michigan; over its lifetime, Line 5 has moved about 80 million barrels of Michigan-based crude to market—and is the primary conduit for this production. About 30% of all the crude oil carried by Line 5 stays in the region, where it's processed by refineries in the greater Detroit area, used to power industry, and turned into the gas, diesel and jet fuel that keep our economy running. Enbridge also contributes to Michigan’s economy, having paid nearly $41 million in property and sales-and-use taxes across the state in 2015.

Q: Some have called for Enbridge to permanently remove Line 5. Why hasn’t this been done?

A lot of people and businesses depend on the light crude oil and natural gas liquids delivered by Line 5. Without it, oil would be shipped by barge or the state’s access to affordable, secure energy would be compromised.

Q: What would happen if there were a leak or spill?

If there is a change in pressure or flow, Enbridge can remotely shut off flow in three minutes and activate trained responders. A response plan, which reflects input from the U.S. Coast Guard and Environmental Protection Agency, is in place, and local emergency responders are trained on it and prepared to respond if an incident were to happen.

Q: Has the Line 5 pipeline moved from its original placement?
GPS data collected from in-line testing shows no measurable movement of the pipes under the Straits since the first GPS measurements were taken 10 years ago.

To learn more about how we’re protecting the Straits, please see our Operational Reliability Plan.

Q: Is the Line 5 Indian River crossing permitted?

Yes. The Line 5 Indian River crossing received a permit in 1953.