Acid rain from oilsands having less impact than expected on boreal forest, studies find

Emissions from large oilsands projects may be having less impact on the boreal forest than expected, according to a series of studies made public last week.

The studies are based on data collected from jack pine stands in northeast Alberta over 20 years by the Wood Buffalo Environmental Association. The non-profit group is made up of representation from industry, government agencies, First Nation and Métis communities, and environmental organizations.

The association is funded by the federal and provincial governments' Oil Sands Monitoring Program.

"It's been a long-standing concern in the region that air emissions could be having an effect in the broader regional forests," said adviser Ken Foster, an independent environmental consultant who has been involved with the project since its inception in 1997.

The primary concern is acidification of the forests by the accumulation of sulphur and nitrogen emitted from the mines and upgrading plants as nitrogen dioxide, nitrogen monoxide and sulphur dioxide, Foster said at a June 18 presentation hosted by WBEA at Keyano College in Fort McMurray.

A widely-publicized study predicted emissions from Alberta oilsands could eventually acidify an area the size of Germany.

Air Quality Research Division, Environment and Climate Change Canada
Air Quality Research Division, Environment and Climate Change Canada

But the four researchers who presented their studies June 18 said they found no impact of acidification on the growth of trees or other plants despite finding higher levels of nitrogen and sulphur.

WBEA sampled air, soil, plants and lichens in jack pine stands within a 200-kilometre radius of Fort McMurray every six years.

Over the last year, researchers began analyzing and writing up the data.

Some of those results have been published in Science of the Total Environment, an international peer-reviewed journal covering environmental science. Other results are still being peer-reviewed.

Instead of wide-spread acidification, researchers found that the nitric oxides and sulphur dioxides were being neutralized by calcium and strontium present in "fugitive dust" kicked up from petroleum coke piles and road dust.

The neutralized nitrogen and sulphur then acted as fertilizer, Foster said.

The researchers recorded more plants and more species of plants in the testing areas, indicating the nitrogen and sulphur were acting as a fertilizer.

Jamie Malbeuf/CBC
Jamie Malbeuf/CBC

The findings could change the modelling for the acidification of the boreal forest by industrial activity in the oilsands region, Foster said.

"Monitoring and the modelling are not aligned well," he said. "If the model is only estimating one parameter, but not its counter-balancing parameter, that is going to overestimate acidification."

Matthew Landis, an advisor on the project and senior research environmental health scientist at the U.S. Environmental Protection Agency, said the studies will allow industry to pinpoint specific activities leading to the deposit of chemicals.

Industry can use the data to "go back and make intelligent choices of how they want to spend their money in terms of [lowering] emissions," Landis said.