NRCan researchers working to reduce water and land damage from oil sands production

Researchers from Natural Resources Canada (NRCan) are refining technology that will reduce the amount of water used for oil sands recovery by half, creating dry tailings that will allow for significant land reclamation. The new process could help to divert massive volumes of oil sands tailings (a mixture of water, clay, sand and residual bitumen) from massive containment ponds that pose environmental risk.

The technology advancements were outlined by Dr Randy Mikula, an Alberta-based NRCan researcher, on Parliament Hill as part of the Bacon & Eggheads speaker series. In his presentation — Trading Water for Oil: Tailings Management in Surface-Mined Oil Sands — Mikula attempted to put a positive spin on a growing environmental problem in Alberta's north as oil sand production is poised to dramatically increase once new projects and oil companies come on stream.

Oil sands production currently consumes four barrels of water for every barrel of oil (once reusable water is discounted). At current levels, the amount of water being removed from the Athabasca River for oil sands production is equal to the amount of water the City of Toronto uses in a year.

NRCan's breakthrough achievement is to add gypsum (calcium salt) to oil sand tailings, consolidating them and allowing them to be stacked rather than poured into containment ponds. Since gypsum is produced on site by the scrapping of flu gas, two waste streams are brought together to address the problem of growing contaminant ponds.

Mikula says that current oil sands reserves that can be surface-mined total 35 billion barrels, representing 140 years of oil at current production rates. But when five more companies join those now operating — and current players implement expansion plans — production will be boosted three-to-five times. Such an escalation in production will dramatically reduce the remaining production to 30-45 years and increase waste water and land loss.

The prevailing practice of water capping (wet landscape reclamation) was approved 20 years ago and has resulted in massive artificial lakes that now hold more than one billion cubic metres of tailings and are visible from space through satellite imagery.

"Nobody thought it was a good idea but it was the best technology at the time," says Mikula, head of emulsions and tailings at NRCan's CANMET Technology Centre in Devon AB. "It's kind of a grim picture."

Suncor is currently testing the NRCan technology for stackable tailings and will begin reclaiming land lost to tailings as early as 2009. But plans are afoot to place tailings that can't be dried at the bottom of so-called N-pits for wetlands reclamation.

"I thought it was a bad idea in 1987 and now it's being widely considered. I'm not happy about it," says Mikula.

Still, reducing water usage by half is considered a major improvement over previous oil sands production practices and Mikula says more needs to be done.

"Over the last 10 years we have done a lot more than we have in the previous 30 years and we've got to keep the pace up," he says, adding that accelerating the pace of research will help to match the dramatic increase in oil sands production just over the horizon.

Mikula's Parliamentary presentation was the second in a month focused on the oil sands. On October 25, Univ of Alberta professor, Dr Murray Gray, delivered a presentation entitled Can oil sands production and upgrading be sustainable?

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