Water predictions help restore oil sands

University of Saskatchewan research may be key to restoring the oil sands landscape after mining.

Engineering researchers Lee Barbour and Shahabul Alam are the first to create computer models of water balance which include climate change projections that will help the industry design more efficient reclamation soil covers at oil sands sites after mining is complete.

“Our study can help the Canadian oil industry save time and millions of dollars for the design of reclamation covers that support the full restoration of the environment at the sites disturbed by mining,” said Barbour, who is also a researcher at the USask Global Institute for Water Security.

The overall aim is to ensure water balance so that the sites have enough freshwater to support forests and wetlands, while limiting the release of potentially deleterious chemicals from the mine waste.

“It may take many decades to restore a water natural balance, so it’s important to have water models such as ours that assess the impact of future environmental changes on performance of the reclamation site designs,” said Barbour.

Oil sands mines last between 40 and 80 years, and only one site in Alberta has been certified reclaimed since the ‘60s. The Alberta government requires that companies restore the land to an environmental status equivalent to pre-extraction.

Until now, the industry has had to evaluate the performance of reclamation covers based on historical climate and monitoring records.

Barbour and Alam’s models predict the future influence of climate change on the freshwater balance for the Fort McMurray reclamation covers — the soil layers removed before extraction that companies use to cover depleted mine sites. These covers help plants grow back by storing rain and snow, control the release of surface water to wetlands, and stop groundwater from entering the underlying mine waste.    

The results of Alam’s study are published in The Journal of Hydrometeorology. That paper highlights that by the end of the 21^st century, warming temperatures worldwide will likely increase rainfall and snowfall up to 25 per cent in the boreal forest near the oil sands mine sites, along with increases in water evaporation. 

“While plants will have more water to grow overall, they won’t be able to absorb all that water,” said Alam, Barbour’s PhD student. “This will increase the extra water released from the oil sands reclamation sites, with a higher risk for transporting chemicals from the mine waste into the environment.”

Syncrude, which provided funding for the project along with the federal agency NSERC, is already working to include the USask findings in its design practices.

This study is the latest chapter of a longtime USask research project. For the last 20 years, Barbour has been studying the remediation of South Bison Hills, which was part of Syncrude’s original mine and is now home to tall trees and lush vegetation.

Alam, who came from Bangladesh to USask because of the excellence of the university’s water institute, said the next step will be studying risks associated with climate change impacts on the long-term performance of reclamation covers.

“Since climate change is a global crisis, learning from USask world experts will help me mitigate the impact of climate change not only in Canada but also in my home country,” he said.   

Federica Giannelli is a graduate student intern in the USask research profile and impact unit.

This article first ran as part of the 2019 Young Innovators series, an initiative of the USask Research Profile and Impact office in partnership with the Saskatoon StarPhoenix.