To Sarnia, Ontario Length 1,098 mi (1,767 km) Commissioned 1953 | Type oil Diameter 76 cm Province Ontario | |
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Similar Straits State Park, Kalamazoo River, Lake Michigan–Huron, Mackinac Bridge, Mackinac Island | ||
Study enbridge line 5 worst place for great lakes spill
Enbridge Line 5 is a major oil pipeline in the Enbridge Lakehead System, which conveys petroleum from western Canada to eastern Canada via the Great Lakes states. Line 5 is particularly notable for passing under the environmentally sensitive Straits of Mackinac, which connect Lake Michigan to Lake Huron. As of December 2013, it is capable of carrying 540,000 barrels (86,000 m3) of oil per day. It carries synthetic crude, natural gas liquids, sweet crude, and light sour crude.
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Route
The pipeline runs between two major nodes of the Enbridge Pipeline System at Superior, Wisconsin, and Sarnia, Ontario. The Enbridge terminal at Superior conveys western Canadian crude oil from various incoming pipelines (including lines 1–4) to Line 5 and Line 6, which go around the northern and southern shores of Lake Michigan respectively.
From Superior, Line 5 travels east to the Upper Peninsula of Michigan, then runs southeast to Rapid River, near Escanaba. At Rapid River, natural gas liquids (NGL) are side stream delivered for stripping, and the stripped NGLs are reinjected.
From Rapid River, the pipeline runs near the northern shore of Lake Michigan until it reaches the Straits of Mackinac. There the pipeline divides into two separate 20-inch (51 cm) lines, which reunite when they reach the southern side of the straits. The lines are buried until they reach a depth of 65 feet (20 m). The lines descend to a depth of approximately 270 feet (82 m) under the straits.
Once on land again in the Lower Peninsula, Line 5 runs near Interstate 75 to Bay City. At the Lewiston pumping station, US sweet crude may be injected. From Lewiston, Line 5 loops around Saginaw Bay, then runs southeast to the St. Clair River.
Just before the St. Clair River, Line 5 reaches the Marysville pumping station. Volumes destined for Michigan and Ohio refineries such as BP Husky and Marathon Detroit are offloaded there, and transferred to a Sunoco pipeline that runs from Marysville to Toledo.
The line then proceeds east across the St. Clair River to Ontario, where it rejoins Enbridge Line 6 and terminates at Sarnia. Any volumes not destined for Sarnia-area refineries are there pumped into tanks for transfer to Enbridge Line 7.
History
Construction on Line 5 was completed in 1953. The pipelines from western Canada to Superior had been completed in 1950; prior to the construction of Line 5, the crude oil was conveyed from Superior to southern Ontario by oil tankers.
In 2013, the line's capacity was increased by 50,000 barrels (7,900 m3) per day, from 490,000 to 540,000 barrels (78,000 to 86,000 m3). The upgrade involved US$100 million in improvements to pumping stations, but no change to the actual pipes.
Controversies
The 2013 expansion, coupled with the anticipated expansion of the Alberta Clipper pipeline, led to concerns from the National Wildlife Federation and other groups over the possible shipment of diluted bitumen from the Alberta tar sands through Line 5. However, Enbridge has denied any plans to pump such materials. A 2011 toll agreement describes the materials as "condensate, light synthetic, sweet, light sour and NGL," as does a 2013 summary of the Mainline System. Due to national security concerns, however, the Pipeline and Hazardous Materials Safety Administration does not divulge the materials actually carried on major US pipelines, including Line 5.
Public concerns have particularly focused on the risk of a spill under the Straits of Mackinac, and the difficulty of controlling any spill that might occur. According to Enbridge, the pipes under the straits have never leaked, are monitored 24 hours a day, and are regularly inspected by underwater autonomous vehicles. However, there have been numerous spills elsewhere in Michigan from Enbridge pipelines, including a major Line 5 spill at Crystal Falls in 1999, as well as the 2010 Kalamazoo River oil spill on Line 6.
By the end of 2015, eight Michigan counties or municipalities were calling for the retirement of Line 5 including Cheboygan, Cheboygan County, Emmet County, Genesee County, Mackinaw City, Mentor Township, Munising Township, and Wayne County.