Oil sands mining contaminants not found at 200 kilometres
New measuring tool developed by researchers enables scientists to know what would be pre-industrial contaminant levels in the natural environment.
Scientists at the University of Waterloo and Wilfrid Laurier University have developed a way of measuring levels of contamination that existed in river sediments in pre-industrial times.
The study, which was funded by Suncor, but recently published in the peer-reviewed journal Environmental Research Letters, focused on sediments in floodplain lakes of the Athabasca Delta in Alberta.
Using the method, the researchers found that the Alberta oil sands developments have not raised the concentrations of heavy metals 200 kilometres away in the delta.
The University of Waterloo’s announcement of the findings explains how in an area like the Athabasca oil sands, natural features of the environment release contaminant metals. Consequently it is difficult to measure how much impact industrial and mining activities have had.
“Normally, rivers are monitored for pollution upstream and downtream of a pollution source,” says the university’s release. “But this method is problematic in an area like the Athabasca oil sands, where erosion of bitumen-rich riverbanks naturally releases substantial quantities of polycyclic aromatic hydrocarbons and metals into the river.”
But with their new method, the researchers have been able to accurately determine the pre-industrial baseline levels of metals in river sediment to allow regulators to instantly see whether there is evidence of man-made pollution.
Johan Wiklund of the Department of Biology at the University of Waterloo, who is the lead author of the study, says the new methodology can be applied to any river in the world.
The researchers measured eight metals, including nickel, vanadium and zinc in sediments from flood plain lakes in the Athabasca Delta. The lakes were supplied by river floodwaters before the industrial era of 1700-1920.
The team adjusted for variations in river flow and sediment grain size, and then compared the natural baseline to metal concentrations measured between 2010 and 2013 by RAMP (Regional Aquatics Monitoring Program). The researchers conclude “Results show that the concentration of metal contaminants travelling via the Athabasca River to its terminus at the Athabasca Delta has not yet increased as a result of Alberta oil sands development or other human activities.”
The study concentrated on the area 200 kilometres away from the oil sands, a region that is home to several First Nations and Metis communities who are concerned about pollutants from the oils sands mining reaching their lands.
The University of Waterloo and Wilfrid Laurier team next plan to do studies farther upstream, closer to the oil sands mining and processing plants.
The authors of the research study were, beside Johan Wiklund mentioned above: Brent Wolfe, Tom D. Edwards, Andrea Farwell and D. George Dixon.
To read the University of Waterloo report, click here.