Rebuilding land destroyed by oil-sands may not restore it, researchers say

EDMONTON — The Canadian Press

A pickup truck leads a haul vehicle at an oil sands mine near Fort McMurray, Alta., July 9, 2008.Researchers doubt that oilsands-damaged land can be restored to what it was. (Jeff McIntosh/THE CANADIAN PRESS/Jeff McIntosh/THE CANADIAN PRESS)

In a small corner of the vast scrape the oilsands have left on northern Alberta, a small sampling of seeds is gradually warming up in the slow boreal spring.



Painstakingly hand-gathered last fall from sedges, grasses and shrubs at undisturbed marshes and bogs, the seeds were carefully strewn atop a former Syncrude tailings pond, now a crucial pilot project in wetland reclamation. If they sprout, much will rest on those slender shoots of water sedge, slough grass, marsh cinquefoil and bog birch.

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There's the fate of a huge ecosystem being disrupted at an increasing pace. There're the millions of dollars companies have spent studying how to rebuild wetlands destroyed by oil-sands mining. And there's the social licence of an industry that promises to restore land — in the words of one ad — to “where you'd never know there'd been a mine in the first place.”



“The probability of success is extremely high,” said Warren Zubot, a Syncrude senior engineer who's working on the Sandhills project, the rebuilt fen that is home to those scattered seeds.



“I'm very confident that we have the ability to create reclaimed wetlands,” said Christine Daly, wetland reclamation director for Suncor, which has restored a marsh and is working on a fen project of its own.



But academic researchers point out at least half the region's wetlands will be permanently lost. They say millions of tonnes of carbon will be released.



Stable ecosystems may take generations to develop and their final state is unpredictable, while hundreds of square kilometres of pristine bogs, marshes and fens are slated to be torn up at a pace that far outstrips reclamation.



“It makes us angry because they will put some kind of plants back on the landscape, but it will not look the way it was and it will not have the same type of functions,” said Suzanne Bayley, a University of Alberta biologist who has been studying the region for nearly two decades.



“Thinking that wetlands, or in (the oil-sands) case, those peatlands are going to go back to natural states, it's basically unlikely,” said David Moreno-Mateos, a biologist at the University of California Berkeley who recently published an analysis of 621 restored wetlands around the world.



“We don't know the right way to bring them back.”



About 60 per cent of the boreal forest that overlays the oil-sands is in fact composed of wetlands, the most common type of which is a fen.



Fens absorb both ground water and precipitation. They store vast amounts of water, moderating both flood and drought. They host complex plant and animal communities. The plant matter they accumulate turns into huge reserves of carbon in the form of peat.



Ms. Bayley said more than 1,900 square kilometres of fens sit atop mineable oil-sands. Even though current estimates suggest only about 750 square kilometres will be restored as self-sustaining wetlands, that's still one of the largest reclamation efforts in history — and one of the most difficult, she suggested.



“Wetland reclamation is hugely complex.”



Wetlands have been forming either artificially or naturally on oilsands leases for years. The results, said Ms. Bayley, are not encouraging.



She and her colleague Rebecca Rooney compared 20 reclaimed oilsands wetlands that were an average of 16 years old to 25 undisturbed sites in the area. The scientists found 70 per cent of the reclaimed sites were in poor ecological health: lower biodiversity, less-productive plants and more land exposed to erosion.



Those findings echo Mr. Moreno-Mateos's research. He found plant communities and carbon cycling in reclaimed wetlands around the world averaged about three-quarters of what they would if undisturbed — even after a century. And the colder the climate, the slower the recovery.



“Alberta is so cold,” he said. “Things will take a lot more time.”



Then there's the carbon.



University of Alberta water ecologist David Schindler recently discussed the impact of oil-sands wetland disturbance on climate change-causing greenhouse gas emissions with a Senate committee.



He pointed to research conducted by Ms. Rooney that concluded wetlands destroyed in creating the 10 existing and approved oil-sands mines will release between 11 million and 47 million tonnes of carbon. Reclaimed wetlands will begin absorbing carbon again, but their smaller extent means the annual uptake will be up to 7,200 tonnes less.



Water quality is a critical issue.



Both Syncrude's and Suncor's fens will be primarily fed by fresh water. But at Syncrude, some water will seep into the fen from mine tailings below. Rain and snow watering Suncor's fen will have to percolate through small hills built with sand from the bitumen mine. That sand will probably contain salts and residual chemicals.



Although some natural fens are naturally salty, Ms. Bayley found the more “process-affected” water reclaimed wetlands received, the worse they did. Other studies have concluded the same for ducks, amphibians and fish.



Finally, there's unpredictability. Despite the best work of hydrogeologists and biochemists, Mother Nature has her own ideas. Mr. Moreno-Mateos found that reclaimed wetlands developed different plant and animal communities than natural wetlands.



“From what we have found, those wetlands are going to follow their own trajectory, in most of the cases different from what you had before.”



Johnathan Price of the University of Waterloo, who helped design Suncor's pilot fen project, acknowledges there are unknowns.



“As with all reclamation, it doesn't always turn out as you plan ... As to how long it takes for this to evolve, that is possibly decades. I don't know.”



Still, Mr. Price said, wetland science has come a long way. The reclaimed sites may not duplicate what existed before, but they'll be close.



“We don't have a crystal ball, but we're hopeful that we'll get some good plant community ... that is characteristic of some of the reference systems in the area.”



Mr. Price expects the Suncor site to develop good plant cover within a few years.



Ms. Bayley acknowledges that, over time, wetlands can be reclaimed. But reclaimed as what exactly?



“You can't just say, ‘They're going to make it look natural.’ They have to measure.”



Current government regulations stipulate that reclaimed landscapes be self-sustaining, solid enough to support traffic and able to play at least some of the environmental roles that they did before they were disturbed.



Alberta Environment is only starting to discuss more specific mitigation requirements, said department spokeswoman Carrie Sancartier.



Tracy Scott of Ducks Unlimited is participating in those discussions. He said Alberta is moving toward a policy that measures wetland reclamation in functional terms such as water quality, habitat or carbon storage.



The department is evaluating 18 different ways to measure those functions.



“We're not very far down this particular road,” Mr. Scott said, although he added the department considers developing that policy a top priority.



In the meantime, oil-sands development continues apace. Included in Mr. Schindler's presentation was a graph showing the gap between disturbed land and reclamation increasing at an exponential rate.



“The main problem is how they've let development get ahead of reclamation,” said Ms. Rooney. “It looks like it's going to continue growing in that manner.



“We currently have no evidence that we really know how to successfully reclaim, but we're continuing to allow tens of thousands of hectares to be disturbed on the promise that, ‘Oh, we'll be able to put it back.“’



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