Natural Resuscitation: Oilsands reclamation work restores Wood Buffalo's Boreal Forest Ecosystem
As Leni Courtorielle hikes through the South Bison Hills on the southwestern corner of the Syncrude lease, striding through lush meadows and passing through stands of white aspen, spruce and jack pine as a chorus of birds twitters away, she reflects on how she may not enjoy the tour de force of her career until she is retired.
But pausing at the dock at Bill’s Lake, which extends over a pond circled by swaying cattails, she says she’s comforted by the achievements of others who have come before, like the late Dr. William Stolte, a hydrologist and University of Saskatchewan professor after whom the wetland is named.
“Look at what has been accomplished here. This used to be a mine site,” she points out, her arm sweeping across the expanse of the 1,000-hectare parcel of mature reclaimed land about 35 kilometres north of Fort McMurray. “It was a long process but now it has been returned to nature, to its pre-mine state. If they weren’t told otherwise, people wouldn’t realize this area was once part of an oil sands operation.
“Amazing things were achieved with this reclaimed land and we have learned so much more over the years that I am confident that the innovative work we are doing now with the fen wetland will eventually result in something just as miraculous.”
A civil engineer by training, Courtorielle has been with Syncrude Canada Ltd. since 2002, having joined the company straight from university. She has worked in various areas of reclamation but now is a planner and landform designer involved in transforming what once was the East Mine into forest and wetlands, including the first created fen – a type of groundwater-fed wetland. Wetlands make up about 60 per cent of Northern Alberta’s boreal ecosystem.
“I’m just a small portion of the process, but it’s been rewarding to see the evolution of reclamation in the eight years that I’ve been with Syncrude and it’s exciting to see where we’re headed,” says Courtorielle, who is originally from Bella Bella, B.C.
“I’m glad that some areas have already been reclaimed so that I can see how it will progress. To say that we just put dirt on the ground is not true. We do much more than that with disturbed land.”
Indeed, after he toured the South Bison Hills during his controversial oil sands visit in late September, Hollywood director James Cameron told reporters that he hadn’t contemplated “the complexity of having to recreate a habitat from nothing.” Reclamation is “on the one hand quite daunting, and on the other hand absolutely necessary,” he noted.
“Some people think we go buy trees and stick them in the ground, but that’s not how it works. Plans must be made years in advance,” says Imperial Oil Ltd.’s Hanna Janzen, environmental compliance lead at the Kearl Lake oil sands project, which is at the construction stage.
“The stuff we put back must be native to the area. The oil companies have agreements to collect and store seeds, but seeds still have to be replaced. We just can’t go somewhere, dig up some trees and relocate them to the site.”
Janzen, who has an undergraduate degree in chemical engineering, specializing in the environment, and a joint Master’s degree in chemical engineering and microbiology, was previously the environmental team leader overseeing the development of Imperial’s Cold Lake wetland reclamation pilot project.
“Although I grew up in Calgary, I never thought I would be doing anything related to the oil and gas industry,” she says. “I knew I was going to work in the environmental field, but who would have imagined that I would get to do such innovative and cutting-edge work in the oil sands?
“From what you read in the media, this industry is not portrayed as environmentally responsible, yet that is the opposite of what I have experienced. It is here that I have found a way to make a difference.”
In 2008, Gateway Hill, with its gently rolling forests, lookout points, and 4.5-kilometre interpretative trail system, became the first former oil sands site to be officially certified as reclaimed by the Alberta government. Companies are required to remediate the land that they disturb according to certain standards, returning it to a self-sustaining state capable of supporting the diverse flora and fauna of the boreal forest.
The Gateway Hill area had been used as a parking spot for overburden material removed during open pit mining, and when it was decommissioned in the early 1980s, the latter stages of the rehabilitation process commenced. Reclamation is not tagged on when a project peters out. It actually starts with the opening of a mine, and planning and preparation is ongoing throughout its life in order to be ready for the day when the big machinery leaves and the natural habitat will be coached back.
Reclamation is multifaceted, requiring a variety of scientific and technical skills to reach the end goal. It involves landform grading and design, cover soil salvage and placement, and re-vegetation – which entails seeding, fertilizing, tree planting and seed collection, always using local plant species. Subsequently, there is regular monitoring of vegetation, pests and wildlife.
Nearby Gateway Hill is the South Bison Hills area, which is home to 12 wood bison, part of a herd of about 300 that Syncrude manages in partnership with the Fort McKay First Nation. The operation started in 1993 with 32 animals. To be certified, reclaimed land must have public access, so while other parcels such as South Bison Hills may not be certified, that doesn’t mean they’re not reclaimed.
Syncrude’s West Mine is being reclaimed as a lake using water capping tailings technology, which the company has experimented with on 11 test ponds. The product of 20 years of research, water capping involves placing a layer of fresh water over a deposit of fine tailings. A byproduct of oil sands mining, tailings are what is left over after bitumen is extracted – a mixture of water, sand, silt, clay, trace metals and hydrocarbon residue. Base Mine Lake will be about seven square kilometres in size and more than 60 metres deep, and will be monitored for many years to come.
As part of the reclamation process at the 1,100-hectare East Mine, Courtorielle is participating in a project to establish the Sandhill Fen, which will take up about 52 hectares. Mining ceased in 2001 but long before that, prior even to the first load of oil sands being carted away, so-called closure plans, subject to stakeholder and regulatory approval, had been drawn up detailing how the affected areas would eventually be reclaimed.
Courtorielle notes that oil sands operators are required to re-establish any disturbed habitat to a state that reflects its pre-mine makeup. For instance, if an area was previously 40-per-cent uplands, then it would subsequently have to be 40-per-cent uplands.
“I actually did two years of mine planning to better understand the mine process,” she explains. “I need to comprehend what the actual disturbance is that occurs, what those areas have gone through and the kinds of designs that should be considered – trying to make sure they integrate with other areas that are disturbed or undisturbed or reclaimed. There are a lot of considerations.
“It’s not cut and dried. You actually have to think very carefully about the process and how the land is going to be shaped.”
Step by step by step
The former mine site was progressively filled in with layers of composite tailings, tailings sand and coarser road-building sand, Courtorielle details. Composite tails combine fine tails with gypsum and sand, a mixture that causes the tailings to settle faster. Hummocks were contoured and covered with a stratum of what is known as LFH – litter, fibric, humic material – and some coarse woody debristo control erosion.
LFH covers the forest topsoil and is a fertile source of seeds and other organic matter that encourages germination. Indeed, green sprigs are already sprouting – bright spots amidst the greys and browns of the hummocks.
Like other soil that is salvaged, stockpiled and awaiting further use down the road, LFH is carefully collected from designated areas for future purposes. However, the goal is to use it as fast as possible, preferably through what is known as direct placement.
“LFH consists of all the leaves and the seeds and other things that have fallen to the forest floor and created a thin layer that could range from five centimetres to 35 centimetres deep. It is the crucial stuff that enhances the re-establishment of native plant species,” Courtorielle elaborates. “We try to take care of the LFH in the summer. If you’re only harvesting five to 35 centimetres, it’s a lot easier to do that when it’s warm than in the wintertime.
“We still do some collecting in the winter, and it is amazing to watch a dozer operator scrape off that portion. If you tell them that you want 15 centimetres, you’ll get 15 centimetres; they’re incredibly skilled.”
With the hummocks or upland portion of the fen in place, the lowlands are next on the agenda. Courtorielle says that material will be brought in during the winter when it is easier to travel on capped tailings sand because water can be better controlled. First, matrix peat – a peat-mineral mix or a peat layer over top of clay – will be introduced. There are under-drains that will take the water from the tailing sands and pump it towards the south. Next, a one-hectare area of live peat mats, also salvaged from future mining sites that are being cleared, will be incorporated into the peat matrix, as well as some clay islands.
The lowlands will be fed by water draining down from the uplands, which have a one-per-cent grade. The water will be pumped in from one of Syncrude’s freshwater areas. There will be a holding pond that will be released over time, supplemented by natural rain. A group of researchers is deciding what kinds of trees and shrubs will subsequently be planted. The area will be studied for probably 10 years before certification is sought, hopefully enriching reclamation research and sparking new ideas on restoring disturbed land.
“We’re hoping that it’s going to tell us a lot because this is leading-edge research,” says Courtorielle. “It’s a giant playground for researchers and reclamation environmentalists. When you see areas that have been disturbed return to life, it’s pretty satisfying. We can feel really proud of the work that we do.”
Construction is underway but actual production operations are not expected to start until late 2012 at the site of the Kearl oil sands mine, which is about 70 kilometres northeast of Fort McMurray. However, Imperial Oil’s Janzen and fellow specialists are already well into preparing for the day when the site will be decommissioned and turned over for reclamation.
“One thing I have learned is the importance of upfront planning,” she emphasizes. “When I was in Cold Lake, it was a mature operation; we were dealing with what was there. With Kearl, there is a real opportunity to think long-term and really consider what to do now to enable people like me to be successful in the future.
“There is a lot of cutting-edge work being done on this project. It is one of the largest projects under construction, and the biggest thing that Imperial has in Western Canada. It is very exciting to be part of something so large-scale and innovative.”
Janzen and her team of environmental specialists are working specifically on salvaging soil; so far, she reports, more than 10 million cubic metres of soil has been moved and saved for future use. She explains that five types of soil are being preserved and segregated into different piles to ensure that there will be enough material down the road to return the disturbed land to a self-sustaining boreal ecosystem – featuring a mixture of coniferous and deciduous forests, wetlands and lakes.
“We work very hard upfront on site assessment and consultation with stakeholders so that when we finally walk away, the whole ecosystem that we have re-established will keep going by itself without us standing by with a watering can. It might look slightly different than before, but it will support the same natural cycles of life.”
Salvaging soil is not simply a matter of bulldozing and sticking it someplace else until it is needed again. First of all, it isn’t just dug up. Janzen explains that they are very carefully salvaging at Kearl on the basis of the precise layers in which it naturally occurs, aided by so-called soil monuments.
“A soil monument is basically like a statue. The soil is stripped and a monument is left showing the layers of soil that were there before – like a geological cross-section of rock or the rings of a tree,” Janzen details. “This indicates how much topsoil there was on this site, then subsoil, and so on. We double-check that at the end for a particular area to make sure that the removed soil is segregated correctly and sent to the right piles.”
Like Courtorielle, Janzen marvels at the equipment operators who meticulously skim off layers of soil while using huge machinery. “When you have a really big piece of equipment with a really big shovel attached, you can imagine what it’s like trying to strip 10 centimetres of soil. All the soil-stripping people also carry a card attached to their I.D. badges that outlines the five categories of soil and gives guidelines so that removal is precise.”
The piles, which are strategically located in designated areas, are quite large and they are exposed to the elements because they are too big to cover. It also becomes important to handle the soil as little as possible because moving it around is not only costly but it degrades quality. As a result, a number of factors come into play.
For instance, as Janzen elaborates, how much to save and how tall the piles should be must be considered. If the mounds are too big, you lose the viability of seeds and propagules that are stored in piles for a long time, and there may be further decomposition of soil. As well, it must be remembered that whenever soil is removed, there ends up being a bigger pile at the end than when you started because of the “swell factor” as it absorbs water or expands after being compacted beneath the surface.
Depending on the size and geometry of a pile, the soil can become too hot and dry out, or it may change too much. Weeds are unwanted intruders, as are animals – usually rodents – who like to bury in and build dens.
“We monitor it for all kinds of potential problems and file annual reports with the regulator,” says Janzen. “There are some new technologies on the horizon but they are still in infant stages – such as technology for scanning, kind of like an MRI for soil piles. Right now, people physically go out and march around and inspect them to make sure they’re not deteriorating.
“A change in dimensions usually suggests a problem – if a pile has become too tall or too wide or has too aggressive a slope. That often means that something is going on.”
Janzen notes that outside third-party soil science experts have also been engaged to monitor soil salvaging at Kearl on a regular basis to ensure that best practices are being followed. “They are a link between theory and practice,” she says. “We just don’t tell the contractors what needs to be done, but we give them specifications on how we expect things to be done, which explain here is how you do this.”
While Kearl has taken planning and preparation to a “new level,” Janzen stresses that “the reclamation picture is not static. We are continually updating closure plans. We don’t just do one model at the beginning and close the book.
“We keep on top of trends and changes with the mine and technology. There are regulatory requirements about updating plans at key milestones – a minimum every three years. We spend a lot of time in consultation with stakeholders.
“We have to do this properly so that the vision is successful 40 years down the road when most of us won’t be around here.”
Syncrude Canada Ltd. has reclaimed more than 20 per cent of the land that has been affected by its mining operations. Since 2005, it has invested more than $203 million, rehabilitating more than 4,500 hectares of the 23,000 hectares that it has disturbed, and planting some five million trees and shrubs.