Engineering professor plays key role in environmental protection at diamond mine

David Sego was part of a team that developed a way to protect groundwater from industrial impact at a northern diamond mine

19 February 2015

Edmonton-A professor in the Department of Civil and Environmental Engineering is part of a team that has won a prestigious national award for discovering ways to protect groundwater from toxic mining waste.

David Sego, who has earned an international reputation as an expert on remediation of mine wastes, specifically tailings, played a key role on the team that won the Natural Sciences, Engineering and Research Council's Synergy Award for Innovation. The team undertook a decade-long research project to protect the environment from diamond mine wastes in the Northwest Territories. The Diavik Waste Rock Research Project is an unprecedented research program that is leading to better mine waste management to protect fragile northern environments for centuries to come.

Diamond mining has provided a major economic boost to the NWT, including Indigenous communities. But the long-term benefits depend on minimizing and preventing acid rock drainage (ARD). Mine wastes often contain sulfide minerals that, when exposed to air and water, form acidic water that can harm fish and aquatic life for hundreds of years, long after the mine has closed.

A 10-year collaboration involving a multidisciplinary team from three Canadian universities and engineers at the Diavik Diamond Mine has determined what causes mining waste and produced methods to predict the effects it will have on the environment.

Led by David Blowes, an expert in the prediction, remediation and prevention of groundwater contamination from mine wastes at the University of Waterloo, researchers used novel analytical techniques-including synchrotron X-rays-and advanced numerical models to enhance the biological and geochemical processes used for controlling the formation of ARD in waste rock piles.

That independent, peer-reviewed science convinced regulators to reduce the amount of Diavik's security deposit, a guarantee companies must provide to ensure that the resources to close a mine will be available in the future. For large mines, these deposits can cost over $100 million.

Sego says that having this kind of impact as a researcher is tremendously gratifying. His research over the years has focused on using the climate and natural environment's natural characteristics to minimize environmental impacts of human activities and the ability to freeze up waste rock piles to decrease potential for future negative impacts of the mine are a clear example of that.

"I've always worked to keep people safe and then to minimize the harm to the environment from a project. I'm very pleased that this project has shown how the climatic environment can be used to minimize the environmental impacts," he said.

The recognition is also important, he says, because it acknowledges rigorous research and encourages more.

"Recognition of the team's efforts is very important as I have always believed a team always achieves better results than the sum of the individuals. Greater use of research teams is required and their efforts need to be better recognized. As my career draws to an end I am pleased with the recognition."

The research team's techniques are now working their way around the globe, helping mining companies worldwide design more cost-effective mitigation strategies that better protect the environment.