Elevated Levels Of Toxins Found Downstream Of Oil Sands Operations

By Peter Prebble, Independent Consultant to SES on Energy & Water Policy

Canada’s oil sands industry is substantially increasing loadings of toxic pollutants to the Athabasca River and to its tributaries – via both air and water pathways.    This is the central finding of a new study published in the September 14, 2010 issue of the highly respected journal Proceedings of the National Academy of Sciences. The study focused on the 13 elements that are considered ‘priority pollutants’ under the US Environmental Protection Agency’s Clean Water Act: antimony, arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium and zinc.

The study is led by award winning University of Alberta scientist Dr. David Schindler.   In undertaking the study, Schindler was joined by five other scientists, including Dr. Jeffrey Short who is highly respected for his work in evaluating the long term impacts of the Exxon Valdez oil spill and Biology Professor Dr. Peter Hodson who has worked extensively in examining how pollutants impact the early life stages of fish.  Two of Schindler’s graduate students, Erin Kelly and Roseanna Radmonovich were also co-authors, as was GIS expert Charlene Nielsen.

The study puts into serious question Alberta Environment’s claim that the pollutants in waters downstream of the oil sands are primarily from natural causes, namely the McMurray Geologic Formation.  The study authors undertook extensive sampling as water flowed through the McMurray Geologic Formation and found that pollution concentrations were unaffected by the contact of river water with the Formation.  In contrast, concentrations of several pollutants in tributary waters of the Athabasca River increased significantly near oil sands operations and were positively correlated with overall land disturbance from oil sands extraction.

The study’s authors consistently found that downstream of the oil sands concentrations of several priority pollutants were significantly higher than upstream of oil sands operations.  Elevated pollution levels continued as far downstream as Lake Athabasca.  Near the point where the Athabasca River discharges into Lake Athabasca, concentrations of eight pollutants in the lake were still as much as double their values upstream of oil sands operations.

The study also examined the pollution impact of bitumen upgraders and found that the concentrations of many pollutants remain elevated as much as 50 kilometres away from the upgraders.  The authors found that, in general, airborne particulate elements decline more quickly with distance from bitumen upgraders than do elements dissolved in water.

Another important finding supports the long held view of the environmental community that oil sands tailings ponds are leaking.  The authors found that, in winter, concentrations of toxic elements such as chromium, mercury and nickel in the Athabasca River were eight times greater just downstream of tailings ponds than upstream of them.   By the end of 2008, oil sands tailings ponds occupied 130 square kilometres of Alberta landscape.  Many of them have been built close to the Athabasca River.

The study should have major implications for the future regulation of the oil sands industry in Canada and the regulation and location of bitumen upgraders.  The full text of the study is publicly accessible on the internet.  For more details google the article title: “Oil sands development contributes elements toxic at low concentrations to the Athabasca River and its tributaries”.

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