Success limited so far in reclaiming tailings ponds
Fort McMurray —Onan early summer day, a Suncor van heads up the hill to an open meadow surrounded by trees. Just seven years earlier, Wapisiw Lookout was covered with a massive tailings pond, the messy, toxic remnants of 30 years of mining.
Today, that 220 hectares marks the only site in the oilsands of northeast Alberta where a tailings pond has been drained, refilled with 65,000 truckloads of soil, then replanted with more than 600,000 trees and shrubs.
As the van pulls ahead, a small black bear dashes out of the bush onto the road, then quickly heads back to the safety of the trees. If all goes according to plan, the wildlife will return along with forest, says Suncor tour co-ordinator Kailyn Park.
The oldest mining operation in the northeast, circa 1967, Suncor is proud of this reclamation project — though it will take 20 years to find out if it will successfully qualify for official certification from the province.
Tailings ponds are one of the most contentious and stubborn environmental impacts of oilsands mining and they’re set to get much bigger as mining expands.
The vast artificial holding ponds are filled with a mix of water, sand, clay, residual bitumen, heavy metals and chemicals from solvents used in separating the oil from the sand. The mixture has a yogurt-like consistency.
The residual bitumen leaves an oily surface on the ponds that is lethal to birds. In 2008, 1,600 ducks died on a nearby Syncrude tailings pond, pushing the ponds issue into international headlines. The polluted pools occupy 30 to 50 per cent of a mine footprint and have more than tripled in size from 50 square kilometres in 2005 to 176 square kilometres in 2010. They are expected to grow by another 40 per cent by some estimates.
It’s not an easy problem to solve. Companies have spent millions on handling mine waste, but it takes years for the fine tailings to settle to the bottom of the holding ponds to clear the water. The ponds could stay on the landscape for decades after the mines close — unless new technology is found.
In 2009, faced with growing public concern, the provincial regulator decided to step in.
The Energy Resources Conservation Board came up with ambitious new rules requiring companies to find ways to shrink the ponds. Companies had two years to reduce pond size by about 50 per cent, mostly by drying the tailings and spreading them on the land.
This Directive 74 was a major shift — for the previous 40 years, managing and cleaning up the ponds had been left to companies’ voluntary efforts outlined in project proposals.
But new technology remains elusive. Companies could not meet the ERC B targets even when the requirements were softened in some cases. So in June 2013, the board suddenly backed off Directive 74 after no company managed to meet the new standards. No one would be penalized for missing the targets, it decided.
The 2009 targets were “too optimistic,” says the regulator. “It will take longer than expected” to meet them.
The ERC B decision to back away was awkward for the provincial government.
In the previous 12 months, Premier Alison Redford had been assuring U.S. audiences that tailing ponds will soon be gone. In an April 2013 speech to the Brookings Institute in New York, Redford told the crowd: “Tailings ponds will disappear from Alberta’s landscape in the very near future and reclamation of existing tailings ponds has begun.”
As it turns out, that prediction was premature.
The Pembina Institute, an environmental think-tank, says the province needs to revive the directive.
Tailings ponds are a threat to groundwater and air quality as well as wildlife, which is especially attracted to polluted water in the winter.
About 11 million litres a day of toxic waste water seeps from the ponds into adjacent water and into the Athabasca River, says Pembina’s Simon Dyer. In addition to chemicals such as naphthenic acids are heavy metals including arsenic, cadmium, copper, lead and zinc, some of which come from solvents added to the bitumen.
Also, the ponds are responsible for fugitive emissions of volatile organic compounds and other air pollutants such as nitrogen oxides and hydrogen sulphide, says Dyer.
The oil industry says companies make a good effort to prevent water from escaping the ponds. For instance, ditches around tailings ponds contain the seepage, says the Canadian Association of Petroleum Producers.
In the wake of Directive 74, the industry took action. In 2011, seven mining companies — Syncrude, Canadian Natural Resources, Suncor, Imperial Oil, Shell, Teck Resources and Total E&P— collaborated to create the Oilsands Tailings Consortium. They agreed to share their research and put $90 million into a renewed joint effort to solve the tailings problem.
Out of this came several joint projects.
Syncrude, the second oldest miner, has plans to build a huge, $3-billion centrifuge to spin tailings sludge and remove the water. The remaining dry tailings can be spread on the land. CNRL is testing the use of carbon dioxide injected into tailings ponds to help the particles settle faster. That would leave cleaner water on top ready to be recycled.
Shell is using a process called “atmospheric fines drying,” which involves using a large barge to collect mature fine tailings (MFT) from the tailings pond and transferring them to a drying area. “The mature fine tailings are then mixed with flocculants — chemical agents which help bring the fine clay particles in the MFT together — and placed on a sloped surface to help speed up the release of water from the clay,” Shell said in a 2010 news release. “The released water runs down the sloped surface to a collection area and is returned to the external tailings facility for reuse in the extraction process. What remains are deposits that are further dried to meet strength and reclamation requirements.”
Suncor is trying a new approach — mixing polymer flocculants with tailings to make the clay particles stick together — while Syncrude is the first to try one of the more controversial solutions, an end-pit lake.
In November 2012, Syncrude got approval from the province to pump millions of litres of fresh water into a 20-year-old tailings pond that will form a five-metre cap of clean water on Base Mine Lake. In mining parlance, it’s called an end-pit lake, though not all end-pit lakes contain toxic tailings.
The theory is that heavier tailings and toxic material will stay at the bottom while a freshwater cap will support the growth of bugs and bacteria to create an ecosystem that will eventually support fish life. Over time, bacteria at the bottom of the lake will eat the toxic substances.
The company is confident the demonstration project will be successful because they’ve proven the method on smaller test ponds, Glen Rovang, Syncrude’s manager of research, told the Journal in December 2012.
“It’s very exciting,” Rovang said. “We’ll get aquatic reclamation and very efficient, low-energy tailings management.”
Brett Purdy, tailings expert in Alberta Environment and Sustainable Resources, says the key question is: Will it take years or decades for tailings ponds covered with a fresh water cap to support a natural ecosystem?
“What is the acceptable timeline that meets the needs of stakeholders and the government of Alberta, which is responsible for protecting the public interest?” said Purdy, declining to specify what that timeline ought to be.
If Syncrude is successful, that would be good news for other mining companies. They have already submitted plans to build about 30 such artificial end-pit lakes over the next 50 years and more than half will be used to store tailings permanently. Critics aren’t so sure. The Pembina Institute warns: “If after decades this process is found not to work, then Alberta will be left with dozens of toxic lakes and a costly liability.”
A technical report on end-pit lakes done for the province also called for caution. “When scientific -uncertainty is high and the potential for substantial negative and environmental impact exists — a likely scenario with end-pit lakes — decision-makers and designers should err on the side of caution,” writes the Cumulative Environmental Man agement Association.
Alberta Environment was expected to release its own plan to deal with the oldest tailings ponds this year. Those older ponds were exempted from Directive 74.
The new Alberta Energy Regulator, which replaced the ERC B in June 2013, will issue its next report on tailings in 2015 — though industry is already warning that may be too soon.
Meanwhile, in March 2012, the seven companies in the tailings consortium morphed into Canadian Oilsands Innovation Alliance. They also set up a collaboration with a provincial government research agency, called Alberta Innovates — Energy and Environment Solutions, to track the best technology for cleaning up and reducing tailings ponds.
“We laud the commitment of industry who shared propriety data around their tailings technology development … for the advancement of science and the industry as a whole,” said Eddy Isaacs, CEO of Alberta Innovates.