Line 5 and the History of Canada-US Hydrocarbon Pipelines

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Earlier this year, Michigan Governor Gretchen Whitmer moved to terminate Enbridge’s easement for its Line 5 pipeline. Built some seventy years ago, Line 5 daily transports about 23 millions gallons of oil and natural gas liquids, crossing through Michigan, including 4.5 miles of dual pipelines running along the bottom of the Straits of Mackinac.

The matter is currently before the courts. The Canadian government has filed an amicus brief in support of Enbridge, while the company has defied the governor’s order to stop operating the line by May 12. Whitmer, for her part, has threatened the seizure of any post-May 12 profits. 

With this dispute ongoing, I wanted to provide some historical and personal background. I’m writing a book on the history of Canada-US energy and environmental relations, of which crossborder pipelines are a major part. It also just so happens that I’m a Canadian living in Michigan – in Kalamazoo no less, where Enbridge’s Line 6B disgorged over 1 million gallons of diluted bitumen in a 2010 spill. In this post I’ll take readers on a quick tour of the historical landscape of crossborder pipelines before zeroing in the Line 5 case.

Map of pipelines in Great Lakes Region. By Jason Glatz (Western Michigan University Libraries)

Petroleum Pipelines in the Early Cold War

The discovery of oil in Alberta soon after the end of the Second World War set off a range of discoveries in the Canadian west. The Canadian and Albertan governments actively encouraged American foreign investment since they had the experience and capability domestic industry and finance lacked. American financing could also help, somewhat paradoxically, with the goal of making Canada less dependent on American fossil fuels. But this also meant that foreign multinationals controlled much of the Canadian fossil fuel industry. 

This postwar hydrocarbon expansion sparked a long-lasting boom in pipeline construction. In 1949, Ottawa passed the Pipelines Act which affirmed dominion control over interprovincial and international oil and gas pipelines. The National Energy Board (NEB) was created in 1959, superseding the Fluid and Electricity Exportation Act (the creation of the NEB was a partial recognition that fossil fuels were for the first time passing electricity as the main form of energy sent south across the border). 

By the 1950s, Alberta produced enough oil for all of Canadian domestic needs. A number of oil and gas pipelines would come to link Canadian producers to US markets.[1] While Washington was, and would remain for some time, wary of hurting its own producers, US oil imports from Canadian sources increased steadily, from 4.9 percent of total U.S. oil imports in 1958 to 11.7 percent in 1962, and 18.7 percent by 1967 (significantly exceeding imports from Middle East). During this period, oil and gas export proposals met with little political or public resistance in Canada. 

Between 1950 and 1970, three major liquid hydrocarbon pipelines were built across the border: Interprovincial, TransMountain, and Montreal. The latter involves several sizes of line from Portland, Maine that transport primarily non-North American oil to Montreal. The TransMountain Pipeline company’s oil pipeline from Edmonton to Vancouver was completed in 1953, and then extended into Washington State. 

Canadian petroleum production and exports. From Statistics Canada

In 1950, Inter-Provincial Pipelines— Enbridge as of 1988 — opened the Interprovincial pipeline from Alberta to the head of the Great Lakes at Superior, Wisconsin. From there a spider web of pipelines were built branching out through the Great Lakes, constituting the Lakehead system. This includes Line 5, built in 1953. [if you want, you can link to the map I made that animates the growth of the Interprovincial system from 1950-1979 here]

Natural Gas Pipelines in the Early Cold War

Natural gas pipelines were built under the Detroit and Niagara Rivers in the post-Second World War years, as well as between Alberta and Montana. An Alaskan pipeline dipped into Canadian territory. There were talks of running what emerged as the TransCanada Pipeline partly through the US, but after considerably controversy (the Great Pipeline Debate in 1956, anyone?), it was placed entirely in Canadian territory. Lateral lines from TransCanada’s pipeline went to the Massena-Ogdensburg area by way of Cornwall, and the company also built a 10-inch pipeline to Burlington, Vermont. In 1957, the Westcoast Energy Inc. system began delivering natural gas from northeastern British Columbia to the lower mainland and to United States markets. A new pipeline connected with the TransCanada line in Manitoba to bring gas to central Wisconsin. Another pipeline opened in 1961 to send Albertan gas to the US, crossing the international border in eastern British Columbia. 

Canadian natural gas production and exports. From Statistics Canada

Continental Integration

The National Oil Policy (NOP), announced by the Diefenbaker government in 1961, was largely designed around maintaining exemptions for Canadian fossil fuel exports to the United States. The NOP created an east-west dividing line at the Ottawa Valley. Essentially, Canada was using the oil it developed at home to supply the country west of that line, while selling the higher-priced surplus to the US at a higher price. Quebec and eastern Canada, meanwhile, received cheaper foreign oil.

Instead of embarking upon a policy of national self-sufficiency in oil, this NOP approach was a commitment to furthering a continental oil relationship. That reflected the wishes of American capital that controlled the main fossil fuel companies in Canada. But the Diefenbaker government was happy, as had been its Liberal predecessors, to largely leave the burden and risk of developing fossil fuel resources to the private sector. Cheaper oil and quicker growth was the tradeoff for less Canadian control over this sector. 

Things would continue on much this way until Pierre Trudeau threw a curveball into Canada-US energy relations with the National Energy Policy.[2] That was essentially reversed under Mulroney and the free trade agreements of the late twentieth century. In 1977 the two countries signed the Transit Pipeline Treaty; in this under-the-radar accord, both countries pledged not to hamper, or interfere with, transborder hydrocarbon flows. 

By the end of the twentieth century, Canada was the largest supplier of crude oil to the US, and tar sands investment and development was really ramping up.  Both Canada and the US were, by that time, petro-states to varying degrees. More pipelines were installed to move these energy exports. The Express Pipeline came online in 1997, transporting crude oil from Alberta to markets in Montana, Utah, Wyoming, and Colorado. Three years later the Alliance Pipeline started exporting natural gas from Alberta to Illinois. In 2000, the Maritimes & Northeast pipeline opened. This line runs natural gas from offshore Nova Scotia to Massachusetts, with lateral lines supplying communities along the way.

TransCanada Pipelines began transporting crude oil on its newly-built Keystone pipeline in 2011. Then came the controversy over its expansion, the Keystone XL proposal. Enbridge is now in the process of building another new line, which runs from Alberta to Superior, Wisconsin. 


The above history makes clear that the two nations have experienced a fairly integrated and amicable relationship when it comes to hydrocarbon exports and infrastructure. Of course, that has been frayed as of late by incidents such as the 2010 Kalamazoo River oil spill and the drawn-out politics of the Keystone XL expansion.  

As mentioned above, in 2010 Enbridge’s Line 6B had a major spill into the Kalamazoo River (Enbridge recently renamed 6B as Pipeline 78, apparently to obscure this past history). I’ve previously written for The Otter about this spill. I won’t rehash that here except to point out a few salient facts: it took Enbridge over 17 hours to detect the spill (in the meantime, it increased pressure), then the company obfuscated about whether it was heavy dilbit (significantly impeding the clean-up response), and even though it is clear that at least a million gallons leaked out, Enbridge claims it was far less.

It isn’t just large catastrophic breaks. Smaller pipeline spills are legion, as Sean Kheraj has detailed.  And Line 5 specifically, as the Michigan-based water advocacy group FLOW points out, has failed at least 33 times since 1968, spilling more than 1.1 million gallons of oil in Michigan and Wisconsin; its larger network had 1,364 failures that spilled 9.8 million gallons of oil from 1996-2018.

Line 5

Line 5 crosses under the Straits of Mackinac, one of Michigan’s most celebrated and cherished landmarks, which connects Lakes Michigan and Huron.  Modelling shows that this would be pretty much the worst spot in the Great Lakes for an oil spill. If Enbridge couldn’t effectively respond to the Kalamazoo spill, how it is going to respond to a pipeline failure deep underwater, especially when there is ice cover? Enbridge’s plan is to eventually build a new tunnel to house the pipelines – with the taxpayers apparently footing the bill. 

The Straits of Mackinac. Photo by author.
Straits of Mackinac. Photo by author

Officials from the fossil fuel industry and the Canadian/Albertan governments have trotted out their ridiculous claims about lost jobs and profits if Line 5 is closed. As always, these are laughably and ludicrously inflated. Apparently Ontario will collapse if Line 5 is closed!?

A lot of noise is being made about Whitmer’s closure action violating the 1977 treaty mentioned above. But its applicability here is highly dubious for several reasons. First, the treaty’s intention is to prevent interference with fossil fuels already in transit, not deal with the bigger issue of a pipeline’s feasibility and legality. Second, why would this treaty apply to an internal domestic matter, such as the right of a state to grant permission for a pipeline to cross its internal waters?

Moreover, if we stay on the legal side of the ledger, there are strong grounds for arguing that Enbridge’s operation of Line 5 is illegal on several scores: it violates the public trust doctrine, it has violated the terms of the original 1953 easement, and it violates Tribal Treaty rights in the US. Line 5 basically uses Michigan as a short cut for getting hydrocarbons from western to eastern Canada; Michigan bears the bulk of the risk and very little of the benefits. In our current era of globalized neo-liberalism, fossil fuels and fossil fuel companies seemingly have more rights than citizens and their elected representatives. 

As a Canadian, I’m also appalled at the hypocrisy of Enbridge, with the support of the Canadian state, flouting Whitmer’s order to stop the pipeline. Just imagine how Canadians would react if an American company operated a pipeline in Canadian territory after a premier had revoked permission? Many Canadians may think that, by closing Line 5 and keeping others going, Michigan is trying to have its (oil) cake and it too. But I can assure them that really is about protecting the Straits of Mackinac from a company with a poor track record (though a lot of the blame also needs to go to governmental policies, including in the US, that are all often captured by fossil fuels companies who consequently only have to meet very low regulatory hurdles).

Many fossil fuel apologists are fretting and screaming that pipelines are safer than moving the fossil fuels by road or rail. But opponents of pipelines, including myself, aren’t advocating that the stuff moves by road or rail – they’re advocating that it doesn’t move at all. In addition to the real threat of a spill, the carbon emissions and climate change impacts are what need to be halted. Those are the real environmental, economic, and labor dangers.

As recent history makes clear, Canada is one of the world’s premier climate villains. The likes of Biden and Whitmer are at least making some efforts to reduce fossil fuels and carbon emissions; the Trudeau government is meanwhile doubling down on hydrocarbons and pipelines.  

[1] Paul Chastko, “Anonymity and Ambivalence: The Canadian and American Oil Industry and the Emergence of Continental Oil,” Journal of American History 99,1 (2012): 171.
[2] Tammy Nemeth, “From Conflict to Cooperation: Canada’s US Oil and Gas Policy from the 1970s to the 1980s,” in Michael Behiels, and Reginald Stuart, eds. Transnationalism: Canada-United States History into the Twenty-First Century (Montreal: McGill-Queen’s University Press, 2010), 155-56.

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Daniel is an Associate Professor in the School of the Environment, Geography, and Sustainability at Western Michigan University. He is an editor for The Otter-La loutre and is part of the NiCHE executive. A transnational environmental historian who focuses on Canadian-American border waters and energy issues, particularly in the Great Lakes-St. Lawrence basin, Daniel is the author or co-editor of five books on topics such as the St. Lawrence Seaway, border waters, IJC, and Niagara Falls. His book "Natural Allies: Environment, Energy, and the History of US-Canada Relations" was published in summer 2023. His newest book, an environmental history of Lake Ontario, will be released in 2024. Website: Twitter: @Danny__Mac__


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