Monitoring the Environmental Impact of Canada's Oil Sands Operations

In the 2010 paper entitled “Oil sands development contributes elements toxic at low concentrations to the Athabasca River and its tributaries", Dr. David Schindler of the University of Alberta examines the issue of priority pollutants (PPEs) that are impacting the Athabasca watershed.  These PPEs include arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium and zinc among others.  Here are a few salient points from the study for your illumination.  As a side note, I have a particular affinity for the Athabasca region; during the late 1970s, I spent four months working in the area and developed a great fondness for its aboriginal community.

Let’s open by looking at a map of the Athabasca watershed noting that the oil sands operations are located in the far northeast corner of the watershed, south of Lake Athabasca:

Here is a map showing the distribution of Alberta’s Athabasca Oil Sands:

Lastly, here is a Google Earth view of the oil sands operations and the Athabasca River noting the scale in the bottom left side of the screen capture:

According to the study, bitumen production has risen nearly three-fold from 1995 to 2008 when the study was undertaken and has reached 1.3 million BOPD.  Mining has disturbed 530 square kilometers of boreal forest and tailings ponds cover an area of more than 130 square kilometers. 

Dr. Schindler and his team of researchers studied the presence of 13 elements that are considered to be priority pollutants (PPE) by the US Environmental Protection Agency’s Clean Water Act in waterbodies near northern Alberta’s oil sands developments.  They found that the oil sands industry is responsible for the release of the 13 PPEs and that concentrations of mercury, nickel and thallium in winter snow pack and that concentrations of all 13 PPEs were greater in the summer in Athabasca watershed tributaries that were more disturbed by oil sands development.  Concentrations of PPEs excluding beryllium and selenium were higher on sites downstream of oil sands development than they were in upstream locations.

Some proponents of the current oil sands operations state that the higher concentrations of PPEs in downstream locations are due to erosion of the oil sands formations along the banks of the Athabasca River, a natural process.  The Schindler study was designed to prove or disprove this theory by sampling surface water from 37 sites in February of 2008, 47 sites in June of 2008 and the snow pack at an additional 31 sites were sampled in March of 2008, both upstream and downstream of the oil sands mining and processing locations.  Samples were taken at three sites along each of four tributaries of the Athabasca River that are affected by oil sands development (upstream and downstream of operations) and at two undeveloped reference tributaries.

Analysis of the data showed researchers that the depositional patterns of the PPE were consistent with an atmospheric source, confirming that particulate matter from the oil sands upgraders released PPEs into the atmosphere.  PPEs were found as far as 85 kilometres away from the oil sands operations.  The study of the snowpack showed that within 50 kilometres of the upgrading facilities, 11,400 metric tons of airborne particulates were deposited in 2008 over approximately 4 months with the majority of the particulates consisting of oil sands bitumen.  Installation of precipitators to control fly ash emissions in the late 1970s took place, and for some time, deposition of particulates declined.  Unfortunately, by 2008, with increased oil sands production, deposition of particulates reached 34,000 metric tons, close to the annual emissions rate before the installation of precipitators.  In addition to areally widespread contamination of PPEs , local increased concentration of these elements was found adjacent to oil sands development particularly related to land clearing, road dust and mining.

Suncor and Syncrude data shows that emissions of arsenic, lead and mercury have increased by 300 percent between 2001 and 2008.  This is of great concern since the concentration of mercury in fish responds directly to changes in atmospheric deposition of mercury; with the concentration of mercury in fish from the Athabasca River and Delta being elevated already, the situation is critical.

One of the problems facing scientists when attempting to quantify oil sands-related contamination in the Athabasca region is the lack of historical records.  With nearly 40 years of operation behind us, industrial activity has most likely raised the background level of contaminants in the ecosystem.  Oil sands operations have resulted in higher concentrations of PPEs in vegetation and surface soil, making the job of determining the actual natural background level of certain elements almost impossible to quantify.

As I stated earlier, some proponents of oil sands operations feel that much of the contamination of surface water in the Athabasca watershed is related to natural erosion.  Here is Dr. Schindler’s response”

“The pattern of increased PPE concentrations in snow and the river system does not support the claim that contamination of the AR and its tributaries is only from natural erosion of oil sands. Concentrations of PPE did not increase significantly as water flowed through the McMF from midstream to stream mouth sites, in winter or summer (Dataset S3), and element concentrations in bottom and suspended sediments of tributaries did not reflect greater exposure to natural oil sands (25). Previous records of upstream-to-downstream trends in waterborne Ni and Zn concentrations during high flow (26) probably reflect runoff of snowmelt and rain from disturbed areas or areas contaminated by atmospheric deposition.

Instead, our results indicate that the source of PPE was from oil sands development. In tributaries, overall land disturbance caused a major flux of PPE to water (Fig. 2 and Dataset S4). In summer, increased concentrations of many PPE were significantly related to development at midstream and tributary mouth sites (Fig. S1 and Dataset S4). At less disturbed tributary sites, concentrations of most PPE were greatest under winter ice (Dataset S4). However, at more disturbed tributary sites, concentrations of several PPE were greater in summer than winter (Dataset S4), indicating the impact of land disturbance. If the source were natural erosion of oil sands, concentrations at all sites would have been greater in summer than winter.” (my bold)

In conclusion, the study notes that the oil sands industry is responsible for increased loading of PPEs in the Athabasca watershed.  While PPE concentrations do not exceed national drinking water quality guidelines, increased deposition of priority pollutants is of concern to long-term human health, particularly as oil sands production levels ramp up.  As well, a fish consumption warning is in effect for mercury in walleye from the Athabasca River, a situation that will likely get worse as the decades pass.

The Schindler study does show us all one thing; there really is a need for a fully independent, thorough monitoring of the environmental impact of Canada’s oil sands mining industry.  Without that, we will have no idea of what we are leaving behind for future generations of Canadians, particularly those who live in Northern Alberta and Saskatchewan.