One of the biggest and most controversial challenges in the oil sands industry is how to restore mined landscape to its natural state following mine closure.
One way to do this involves replacing lost land with new land by refilling open pit mines created through oil sands removal with soil, and re-vegetating them to emulate the original landscape.
The oil sands regulator has approved in principle the inclusion of end pit lakes in mine closure plans for Syncrude and Suncor.
Industry has been experimenting with how best to build these lakes. Syncrude, for example, has built several trial lakes with good initial results. Tailings and water haven’t mixed, and natural aquatic life has returned to the water. Indeed, the lakes could also be stocked for recreational fishing or as a food source for wild birds.
Through collaboration, it’s expected that industry will get better at designing and implementing end pit lakes. Tailings and land are both key environmental priority areas for Canada’s Oil Sands Innovation Alliance (COSIA).
Not surprisingly, many stakeholders aren’t fans of end pit lakes. They are right to point out that the long-term impacts aren’t known (which is why ongoing experimentation is critical).
Another criticism is that it is simply wrong to make permanent changes to the landscape. However, many people would find new lakes attractive. Man-made lakes, for example, are popular elements of many new urban developments.
The idea of man-made lakes certainly isn’t new to Alberta. In fact, the province’s biggest lake, Abraham Lake in the foothills of the Canadian Rockies, is man-made and there are eleven others like it in Alberta, most built as reservoirs. Beyond Alberta and throughout the world it has been common practice to allow worked-out quarries to fill with rainwater and become boating areas.
Whether end pit lakes in the oil sands region will attract boating and fishing remains to be seen. But so far, they appear to be a viable method to reclaim at least some of the disturbed landscape.