“We know surprisingly little about diluted bitumen in freshwater ecosystems,” she explains. “We don’t understand its environmental fate, we don’t understand its effects on aquatic plants and animals, yet we’re pumping it through pipelines and want to build more pipelines.”

Dilbit hazard becomes a real problem

This potential threat of dilbit pollution became all too real in 2010, when a major spill of diluted bitumen highlighted just how much there is to learn about the behaviour of this substance. The accident took place in southern Michigan, where a pipeline operated by Calgary-based Enbridge Inc. ruptured and released some 3.7 million litres of this material, which subsequently made its way throughout dozens of kilometres of the Kalamazoo River.

It was the first time the US Environmental Protection Agency had attempted to clean up dilbit contamination, which in this single case would generate costs of more than a billion dollars over the next four years. The event also spawned a series of major studies to identify the research that would be necessary to understand and address the environmental impact of this product.

How dilbit became more common

There had been no need for such knowledge – no need for dilbit – when most of the world was awash in cheap crude oil, which typically has a consistency that allows it to pour efficiently enough for easy transport. However, as petroleum producers began to extract oil from the bitumen found in Alberta’s plentiful oil sands, they had to deal with the thick, taffy-like nature of this source. Getting it to flow like standard crude became a matter of diluting the bitumen with light gas condensates.

This relatively simple chemical fix did solve the industry’s transportation problem, even as it added to the supply chain an entirely new product with many unknown characteristics. Nor was this the only aspect of the problem in need of research. While a great deal of work has already been done on how oil spills could affect Canada’s marine coasts, very little scientific inquiry has focused on the lakes and rivers that define the country’s vast interior. In such settings, dilbit can now pose even more of a hazard, as demonstrated by the Michigan spill’s effect on a local population’s source of irrigation and drinking water.

“The pipeline spill in Michigan was a wake-up call for the research community and environmental agencies that — when it comes to dilbit — we’re not dealing with something we’re used to dealing with,” says Dr. Orihel. “Our scientific understanding of dilbit is still only in its infancy, which is why our research is so essential.”

Persuasive science from a wilderness laboratory

Progress in this field is taking place at one of Canada’s most celebrated field research sites: the International Institute for Sustainable Development Experimental Lakes Area (IISD-ELA). Located in northwestern Ontario, since the 1960s this collection of 58 wilderness waters and watersheds, a field station, and research team have provided scientists with a remarkable outdoor laboratory for conducting experiments on a scale that accurately reflects what happens in the environment, as opposed to the rarefied confines of a laboratory.

Special exemptions have been written into provincial and federal law to allow scientists to manipulate these lakes, physically, chemically, or biologically. Over the last 50 years, the ELA has helped us understand everything from which chemicals in detergents cause algal blooms to the impacts of climate change on habitat of lake trout.

The site has been the lynchpin of Dr. Orihel’s own work for more than 15 years, which is why when the ELA lost federal support in 2012, she was inspired to lead a diverse group of Canadians who defended the ongoing value of this uniquely placed field station and research entity. Their arguments contributed to bringing the ELA under new management by the International Institute for Sustainable Development, an international policy think tank, along with support from the Province of Ontario.

Turning lakes into a science experiment

Dr. Orihel and her colleagues are helping dilbit science to mature through their current work at the ELA. In summer 2018, they turned one of the region's lakes into oversized test tubes to study the most fundamental features of dilbit at close range. A set of nine large enclosed tubes, called limnocorrals, each 10 metres in diameter, were sunk into the lakes and anchored to the bottom, effectively isolating the water contained within them. Varying amounts of dilbit were then poured into these chambers, simulating spills of different magnitudes. The researchers then kept a close eye on what happened in each tube in the weeks and months that followed.

For Orihel, this activity was a search for answers to some key questions that are about as elementary as they come:

       What is the fate of dilbit in a freshwater environment?

       What the effect of dilbit on the structure and function of aquatic communities, including bacteria, phytoplankton (microscopic plants), zooplankton (microscopic animals), benthic invertebrates, and emerging insects?

       Which chemicals accumulate in the bodies of aquatic animals, such as mussels, fish, and tadpoles?

       What are the toxic effects of dilbit on these various organisms?

This work was complicated by the fact that exposure to sunlight, moisture, and fluctuations in temperature can rapidly alter dilbit’s physical properties. However, by addressing the questions above,  the hope is that we can advance our scientific understanding of the fate and effects of dilbit in freshwater ecosystems, improve the design of sampling programs to monitor impacts and recovery after accidental dilbit spills, and inform societal and political debates on the environmental risks of building new pipeline projects.

Dr. Orihel is a principal investigator on the BOREAL project along with University of Manitoba environment and geography professor Mark Hanson, with University of Ottawa biology professor Jules Blais as the lead. Their work began three years ago with primary funding from the Natural Sciences and Engineering Research Council of Canada (NSERC), as well as support from Environment and Climate Change Canada, IISD Experimental Lakes Area, and Fisheries and Oceans Canada. Under the supervision of Dr. Orihel, three graduate students from Queen’s — Johanna Mason, Jeffrey Cederwall, and Samuel Patterson — and one Honours student, Hannah Kosicheck, had the tremendous opportunity of conducting their thesis research at IISD-ELA on this project.

For Dr. Orihel, who once feared that the ELA would never again be home to this kind of relevant ecological investigation, playing a central part in this work is nothing less than intoxicating. As Canadians weigh the future of the oil sands, pipelines, and the environmental impact of fossil fuels, she finds herself uniquely placed to make a scientific contribution to the debate.

“We are doing what no else can do anywhere in the world — intentionally spilling dilbit in a freshwater lake to find out what happens,” she explains.