About Line 5
A vital piece of Michigan energy infrastructure since 1953.
Enbridge's Line 5 is a 645-mile, 30-inch-diameter pipeline that travels through Michigan's Upper and Lower Peninsulas, originating in Superior, Wisconsin, and terminating in Sarnia, Ontario, Canada. As it travels under the Straits of Mackinac, Line 5 splits into two 20-inch-diameter, parallel pipelines that are buried onshore and taper off deep underwater, crossing the Straits west of the Mackinac Bridge for a distance of 4.5 miles.
The products moved on Line 5 heat homes and businesses, fuel vehicles, and power industry in the state of Michigan.
Line 5 supplies 65% of propane demand in the Upper Peninsula, and 55% of Michigan's statewide propane needs. Overall, Line 5 transports up to 540,000 barrels per day (bpd) of light crude oil, light synthetic crude, and natural gas liquids (NGLs), which are refined into propane.
Built in 1953 by the Bechtel Corporation to meet extraordinary design and construction standards, the Line 5 Straits of Mackinac crossing remains in excellent condition, and has never experienced a leak in more than 65 years of operation. We’re working hard to keep it that way. We monitor the Line 5 Straits crossing 24/7, using both specially trained staff and sophisticated computer monitoring systems. We also carry out regular inspections of the line, using inline tools, expert divers, and remote operating vehicles (ROVs), going above and beyond regulatory requirements.