For 65 years, Enbridge’s Line 5 has been a critically important conduit for moving Western Canadian and Bakken crude oil and NGLs east across Michigan’s upper and lower peninsulas and into Ontario, where the now-540-Mb/d pipeline feeds Sarnia refineries and petrochemical plants. Some crude from Line 5 also can flow east from Sarnia to Montreal refineries on Line 9. But Enbridge has been under increasing pressure to shut down Line 5 over concern that a rupture under the Straits of Mackinac might cause major environmental damage. At long last, the state of Michigan and Enbridge have reached an agreement to replace the section of Line 5 under the straits by the mid-2020s, and to take steps in the interim to enhance the existing pipeline’s safety. In today’s blog, we consider the significance of the Enbridge pipeline and of the newly reached accord.
As any music lover or sports fan knows, the Mick Jaggers and Tom Bradys of the world get all the attention, but lesser-known members of the band or the team help make the stars shine. The same holds true in the midstream sector, as evidenced by Enbridge’s Line 5 (purple line in Figure 1), a 645-mile pipeline that is part of the company’s much larger Canadian Mainline and Lakehead systems. Line 5 originates at the company’s terminal in Superior, WI, and runs east/southeast through Michigan to Sarnia, ON. The Superior terminal is the end point for five elements of the Mainline/Lakehead systems — Line 1, Line 3 and Line 4 from Edmonton, AB; Line 67 from Hardisty, AB; and Line 2B from Cromer, MB — and has the capacity to handle 2.8 MMb/d of incoming and outgoing liquid hydrocarbons (most of them light, medium or heavy crudes). Line 5 is one of five pipelines out of Superior; it transports “batches” of either light crude, light synthetic crude or NGLs that are sourced primarily in Western Canada (and also in the Bakken) and bound for either Michigan, Sarnia or Montreal (see Refined, Piped, Delivered – They’re Yours for an explanation of how batching works.) At the Straits of Mackinac (dashed red oval) — the four-mile-wide water passage between Michigan’s upper and lower peninsulas (and Lake Michigan and Lake Superior) — the 30-inch-diameter, single-pipe Line 5 splits into two 20-inch-diameter, parallel pipes that are anchored along the strait’s lakebed.