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Contents - Winter 2009

Vol. 2 No. 1

Oilsands: Extreme Makeover

By Brian Cross

Not long ago northeastern Alberta resembled most other Canadian boreal forests, with abundant trees, rolling uplands, swampy bogs and the mosquitoes that inevitably accompany them.

The mosquito population hasn’t changed much, but the landscape has.

To extract one of the region’s natural treasures—oilrich sands that lie beneath the surface—the landscape has been carved away by oilsands mining, sometimes to a depth of 100 metres.

Large tracts of land once filled with trees, wetlands and wildlife are now covered with sophisticated machinery designed to manage massive quantities of sulphur, hydrocarbons, contaminated wastewater, and piles of oilsands tailings.

Recognizing the importance of restoring the northern environment, Canada’s oilsands industry has committed itself to returning the land to the conditions that existed before mining began. To do so, oilsands companies have called on worldleading researchers at the University of Saskatchewan to help convert millions of tonnes of sand, clay, shale and waste material back into natural forests and wetlands.

For civil engineer Lee Barbour, understanding the environmental impact of oilsands activity began back in the late 1990s. He was studying migration of naturally occurring salts around prairie sloughs when he got a call from Clara Qualizza, a scientist with Syncrude Canada who was responsible for overseeing reclamation of huge stockpiles of salt-rich shales.

What began as a small Syncrude research grant has since been parlayed into two large federal Natural Science and Engineering Council of Canada (NSERC) grants involving several U of S researchers and dozens of graduate students.

That collaboration has established the U of S as a critical hub of oilsands reclamation expertise involving engineers, hydrologists, geochemists, hydrogeologists, geographers, toxicologists and soil scientists.

Their research has led to improved provincial reclamation guidelines in Alberta and the new knowledge is helping companies meet their environmental obligations. “The U of S is one of our most important and productive university collaborators on the environmental front,” says Qualizza.

To describe the work being conducted by the U of S multidisciplinary research team, Barbour says, “Think of a simple flower pot that you have in your house or backyard. You want to produce your own little boreal forest [in the flower pot] but all you have to work with is a foundation of soil which contains contaminants of concern to the environment.

“Our job is to try to understand how the choice of reclamation soil—type, thickness, slope, et cetera— affects the distribution and migration of water and potential contaminants in our flower pot.

“If we are successful, we can ultimately provide industry with the information it needs to reconstruct a natural, healthy vegetative community.”

Creating a landscape that supports forest growth is important since all oilsands companies must establish healthy forests fit for logging on the lands they disturb. But reconstructing the landscape in an area that covers hundreds of square kilometres is complex work.

When oilsands operators begin surface mining, they remove the overburden material that covers the bitumen reserves. This overburden material contains elevated salt concentrations that may be detrimental to vegetation.

Jim Hendry, who holds two NSERC Industrial Research Chairs in environmental chemistry, says one of the biggest challenges facing oilsands companies is managing this overburden material to ensure that these soil-borne salts and other toxic substances do not impede future plant growth.

“You can’t just put the overburden back in,” says Hendry.

“You’ve got to generate an active soil zone. . . and if you can keep the salts out of it, then research shows that you will likely be able to grow forests.”

Processing the oilsands creates another set of unique challenges. Extracted oilsands are mixed in a slurry of hot water and chemicals so the raw bitumen can be separated from the sand. The resulting sand tailings, which contain a variety of environmental contaminants, must also be stockpiled and used as landfill.

Other byproducts, including massive amounts of sulphur, coke and contaminated wastewater, must also be stored, monitored and managed. Hendry and other U of S scientists are examining the storage of these materials and assessing potential toxicity of their leachates.

“We’re looking at the environmental implications of this,” says Hendry. “We are asking what is going to happen in the near or the distant future as faras migration of contaminants—whether salts, vanadium, arsenic, selenium, molybdenum or whatever?”

Karsten Liber, director of the U of S Toxicology Centre, says Alberta oilsands activity has spawned pioneering research in areas that have never before been studied.

“What we’re doing with the oilsands here in Canada is unique,” says Liber who also heads the new U of S School of Environment and Sustainability.

Mining and processing industries cumulatively produce millions of cubic metres of contaminated water each day. Liber is evaluating how man-made wetlands can be used to remove contaminants from this water before it is finally released.

Other examples of ground-breaking U of S projects include soil scientist Bing Si’s research into moisture dynamics within coarse-grained overburden soils, civil engineer Amin Elshorbagy’s precipitation and water-runoff model that helps understand the difference between natural and reclaimed landscapes, and geo-environmental engineer Ian Fleming’s studies to determine how naturally occurring hydrocarbon deposits can affect the environment once they have been disturbed by mining.

Barbour points out that research collaborations with the oilsands industry have provided “natural laboratories” for training graduate students. “Syncrude has taken real interest in the wellbeing of our students while respecting our academic integrity and independence,” he says.