The Environmental Impact Statement for Alberta tar sands production ignored a major air pollution pathway, underestimating the damage to the environment.
As bad as the air pollution from this refining is, there's another source that makes toxic polycyclic aromatic hydrocarbon (PAH) levels even worse than predicted based on sources like this one.
Canada's tar sands air pollution problems from toxic polycyclic aromatic hydrocarbons (PAH) are greater than official government values. A major air emissions source, tailings, was ignored in the EIS. The refining process breaks down the heavy hydrocarbons in tar sands increasing hydrocarbon volatility making waste piles a major source of air pollution according to an open access report published Monday in the
Proceedings of the National Academy of Sciences.
Significance
Our study shows that emissions of polycyclic aromatic hydrocarbons estimated in environmental impact assessments conducted to approve developments in the Athabasca oil sands region are likely too low. This finding implies that environmental concentrations in exposure-relevant media, such as air, water, and food, estimated using those emissions may also be too low. The potential therefore exists that estimation of future risk to humans and wildlife because of surface mining activity in the Athabasca oil sands region has been underestimated.
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Tar Sands refinery waste ponds, like this tailings pond in Alberta, are major sources of air pollution.
This is a big deal, not only because of the greater damage from tar sands development to people's health and the environment, but also because the regulatory basis for approving expansion of tar sands development was flawed. The PNAS report explained that the authors of the EIS
used the wrong methodology to calculate PAH emissions to the air.
Despite taking into account PAH emissions from stacks, mine vehicles, mine faces, plant fugitives, and tailings areas, the estimated EIA emissions were insufficient to explain contaminant levels measured in the environment. This insufficiency may be because the EIA estimates zero emissions of all PAHs except naphthalene from tailings areas, plant fugitives, and mine faces, an unrealistic estimation considering the oil sands
extraction and upgrading processes. The extraction and upgrading processes, which involve mixing with water at high temperatures in addition to aeration and thermal cracking, should facilitate the transfer of even higher molecular weight PAHs to the gas phase.
These inconsistencies suggest major alteration is required in the methodology used to estimate PAH emissions from different sources in environmental impact assessments, (my bolding) such as that described in ref 42.
Moreover, the evaporation of PAHs from tailings is an additional pathway for long-distance water pollution.
Accounting for evaporative emissions (e.g., from tailings pond disposal) provides a more realistic representation of PAH [polycyclic aromatic hydrocarbons] distribution in the AOSR [Athabasca oil sands region]. Such indirect emissions to air were found to be a greater contributor of PAHs to the AOSR atmosphere relative to reported direct emissions to air. The indirect pathway transporting uncontrolled releases of PAHs to aquatic systems via the atmosphere may be as significant a contributor of PAHs to aquatic systems as other supply pathways.
This report casts a shadow of doubt on the recent U.S. Department of State EIS determination that Keystone XL would have minimal environmental impact.
Simon Dyer, director of Alberta and the north for the Pembina Institute, said the study raises a number of issues.
“Decision-makers need to (consider) this information in determining if it is appropriate to approve new projects,” he said. “Regulatory submissions already show that planned production will exceed legal limits for pollutants which means approvals must be slowed or better technologies implemented.”