Regulatory documents for Shell's proposed Jackpine mine expansion say annual levels of sulphur dioxide and nitrogen dioxide are likely to push past limits contained in the province's Lower Athabasca Regional Plan if all currently planned developments proceed.
The documents, filed late last week, also provide what may be the clearest picture yet of what impact two decades of development have had on northeastern Alberta.
"It validates the concern that many stakeholders have raised about the cumulative pace and scale of development," said Simon Dyer of the Pembina Institute. "It's the first real test of the (plan)."
Shell filed the papers after the Canadian Environmental Assessment Agency asked the company to give a clearer account of how the environment of the oilsands region has changed since development began and what part the Jackpine expansion would play. Written by environmental consultants Golder and Associates, the document estimates how levels of the two gases have grown over the years.
Average annual levels of sulphur dioxide are estimated at about 20 times what they would naturally be over a large area from Fort MacMurray to about 100 kilometres north. Nitrogen dioxide is estimated to be at least 10 times pre-development levels — although the report acknowledges hard data from that time is spotty.
And if all the projects that have been announced publicly or are in the regulatory process go ahead, the pollutants are projected to exceed what are supposed to be absolute caps.
Sulphur dioxide will reach average annual concentrations of 21.1 micrograms per cubic metre of air, just over the plan's limit of 20 micrograms. Nitrogen dioxide will reach 59.5 micrograms, well over the limit of 45.
Randall Barrett, director of Alberta Environment's northern region, said the projections are derived from models deliberately designed to overestimate emissions as a way to ensure caution.
"It shows us we have to be very diligent in how we are setting pollution controls for any plants in this area, because the computer models are predicting that we are getting close or over some of the air quality (levels)."
Regulators use the models to determine what sort of emission controls to impose on applicants, said Barrett.
"What would likely happen is they would go to the most stringent type of air quality pollution control, because the models are predicting you could be over the limit."
Barrett said actual air monitoring data continues to show both sulphur and nitrogen dioxides remain well under their caps. If those gases increase as more facilities come on stream, the plan includes "trigger" levels that would require industry to improve its pollution controls.
"This (modelling) is enforcing how important that monitoring is."
The government is obliged to act if pollutants exceed either the triggers or the absolute caps — an obligation that Environment Minister Diana McQueen has underlined.
"It is a legally binding commitment that holds government accountable to Albertans," she said when announcing the plan Aug. 22.
In an emailed response, a Shell spokesman said the projections are based on assumptions that all planned developments are operating at the same time at full capacity. It adds that some of the proposals have yet to start the regulatory process.
In the document, Shell points out the sulphur dioxide levels are concentrated in areas closest to its mines, regions that should be treated differently. Levels in "non-developed areas" remain below the government's cap, it says.
It also says elevated nitrogen dioxide levels are a result of "over-predicted" emissions from giant trucks used in the mines and suggests those emissions are being reduced as the vehicles are upgraded.
Dyer says the government's plan makes no provision for treating some areas differently than others. He also says contaminants in one area do ultimately spread throughout the region.
An earlier Shell document acknowledges 23 small, mostly unnamed lakes, have already passed their critical load for acid.
The document also lists cumulative effects that aren't yet governed by the regional plan, such as wildlife impacts.
Out of 22 indicator species — including birds, mammals and amphibians — 16 will suffer high or moderate negative consequences even under the current amount of development, it says. Some areas will suffer "moderate" biodiversity loss, even after reclamation efforts.
Shell argues species will rebound as the area is returned to a more natural state and adds there should be enough undisturbed regions to maintain a healthy ecosystem.
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