The Local Environmental Impact of Oil Sands Mining

With the Keystone Pipeline (among others) making the news cycle in both Canada and the United States on a regular basis, I thought it was time to take a look at a study that examines the impact of the oil sands mining process on the ecosystem adjacent to the mined area in the Athabasca region of Northeastern Alberta.

Unfortunately, a piecemeal approach to environmental monitoring in the region has made it difficult for scientists to determine the condition of the Athabasca region prior to the advent of industrial-scale mining making it difficult to measure the impact of the oil industry on the ecosystem since there is no baseline from which to measure.  A recent study by a group of scientists at Canada's Queen's University uses an interesting and indirect approach to see the impact of 50 years of oil sands development by looking at lake sediment records, an idea that is quite appealing to the geoscience community.

Let's start by looking at the size of the impacted area noting that, for scale, the main north-south road  running between Fort McMurray and the southernmost mining site is a four-lane highway:

Roughly 97 percent of Canada's current proven reserves of oil are found in northern Alberta and Saskatchewan, representing the world's third largest oil reserves.  In 1980, oil production from the region was approximately 100,000 BOPD and reached 1.6 million BOPD in 2011 with projections showing that the rate will reach 2.273 million BOPD by 2020.  Obviously, as you can see from the satellite image, the impact on the landscape is already significant with loss of habitat and resulting changes to water quality.  

While the impact that we can see is disturbing, it is what we can't see that may pose a greater risk.  The techniques used to process the oil-laden sand releases contaminants, many of which are carcinogens and rank among the top ten hazardous substances including polycyclic aromatic hydrocarbons or PAHs that are produced by the incomplete combustion of fossil fuels and biomass.

To a chemist, this is what PAHs looks like:

PAHs are a group of over 100 chemicals that are formed as a result of the incomplete burning of coal, oil, natural gas, garbage and even tobacco and charbroiled meat.   These particles can attach themselves to either dust particles or sediment and, in the case of lakes, will settle to the bottom.  Studies show that PAHs can cause harmful effects on skin, body fluids and the ability to fight disease and that they can be reasonably expected to be carcinogenic according to the Agency for Toxic Substances and Disease Registry.

Back to the study.  As I noted earlier, historical background records of PAH levels in the region have been generally lacking to this point.  The oil sands industry-funded Regional Aquatics Monitoring Program (RAMP) which was established in 1997 suggests that PAH levels in the Athabasca River Delta (where the Athabasca River that flows right through the mined area empties into Lake Athabasca) have risen by 30 percent between 1999 and 2009 and yet, there was no significant increase in PAH levels at their control sites.  Other studies have suggested that elevated PAH levels in the Athabasca watershed are related to natural erosion of the oil-sands bearing strata as it outcrops along local rivers.

If not through erosion, how do the polycyclic aromatic hydrocarbons get from the mined area to nearby fresh water bodies?  As the PAHs are emitted from the oil sands upgraders, they are picked up by the wind and carried aloft, the PAHs may also be picked up by the wind from the area being actively mined or from ash created by local forest fires.

To assist the researchers in their quest to determine the pre-mining or background PAH level, they selected five lakes within a 35 kilometre radius of the mining and upgrading sites and an additional lake that was located 90 kilometres northwest of the upgrader.  Here is a map showing the location of the lakes under study and their relative location to the mined areas (in pink):

  

Since the scientists are well versed in the study of paleolimnology (the study of past conditions and the history of lakes as recorded in the layers of preserved sediment found at the bottom of lakes), they have the ability to determine the age of each of the layers.

The researchers noted that in the five nearby lakes, the level of PAH concentration began to rise in the years between 1966 and 1972 with three of the lakes showing an exponential increase in the concentration level.    Since the mined area has increased from about 40 hectares (100 acres) in 1970 to about 71,500 hectares (177,000 acres) in 2010, this is not terribly surprising.  As well, lakes to the east of the Athabasca River (i.e. NE20, NE 13 and SE 22) (in the downwind direction) show a marked increase in contamination compared to those to the west of the mined area (i.e.NW35 and SW22) after the mid-1960s as shown on this diagram:

This would indicate that as the prevailing winds blow across the upgrading facilities and surface-mined areas, they pick up PAH in the form of dust particles from upgrader emissions and areas where overburden has been removed from the oil sands-bearing formations.

What is even more interesting is that even the lake located 90 kilometres to the northeast (i.e. far upwind) is showing an increase in PAH concentration since the late 1960s and early 1970s.

While environmentalists are raising alarm bells about the impact of increased oil sands mining on global climate change, it is clear from this study that the impact on the environment goes far beyond the increased emission of greenhouse gases.  Not only is the increased level of PAHs in lake sediments cause for concern, the process of upgrading the oil sands results in the release of both sulphur and nitrogen oxides, key components of acidic precipitation, a situation which is creating even more stress for the Athabasca ecosystem.  

As shown on this graph, as oil production sourced from the mining of oil sands ramps up from 1.6 million BOPD today to 2.27 million BOPD over the next 20 years in reaction to an opening of additional markets for Alberta's synthetic crude, the mined area is most likely to increase in size and scope, resulting in a local ecological situation that will not improve: