Lessons learned from oil sands monitoring, annual report 2012 to 2013

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2012 to 2013: what we have learned

In the oil sands region, a particular challenge is that many of the substances found in the environment occur naturally as well as resulting from development activities. Separating the natural environmental effects from those that are introduced by human activities involves forensic work to establish cause and effect. Without clear cause-and-effect relationships, management actions meant to mitigate environmental impacts may be ineffective.

To date, monitoring and scientific study data show evidence of oil sands development on the surrounding environment, although generally not at levels that are cause for immediate concern. Concentrations of oil sands-related substances (i.e. polycyclic aromatic compounds, acidifying compounds and metals) in air, water, snow and sediments are highest at locations close to oil sands extraction and upgrading facilities. These concentrations decline with increasing distance from development sites, with the highest concentrations found within an approximately 50 km radius from the confluence of the Steepbank and Athabasca rivers.

Laboratory fish and invertebrates exposed to ground and surface waters and to sediment from sites located close to oil sands mining and upgrading facilities showed biological effects related to exposure. However, biological effects were also observed in fish and invertebrates exposed to water and sediments collected from areas of exposed natural bitumen deposits. The development sites also coincide somewhat with naturally exposed bitumen deposits, emphasizing the challenges associated with establishing clear cause-and-effect relationships between development and impacts.

Below in bullet form are some of the key findings based on existing data. The findings below are merely observations based on data, and have not been fully interpreted or evaluated for implications of impacts or cumulative effects. Supporting data and reports are available on the Portal.

Acidifying compounds

• Atmospheric concentrations of NO₂ and SO₂increase near the oil sands development areas and are comparable to, or less than, concentrations typically found near coal-fired power plants, mining smelters or metropolitan areas such as Edmonton.
• Satellite observations from the period 2005 to 2010 show an enhancement of NO₂ over an area of intensive surface mining. Further analysis will be done to assess potential impact and relevance.

Polycyclic aromatic hydrocarbons and polycyclic aromatic compounds

• Polycyclic aromatic compound (PAC) atmospheric concentrations vary considerably across the region. On average, the PAC concentrations in air near mining and upgrading activities are twice as high as the concentrations at sites 50 to 100 kilometres away.
• Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) recorded in lake sediments has steadily increased since oil sands development started in 1970, is detectable up to 100 km from the development.
• Lake sediment polycyclic aromatic hydrocarbon (PAH) concentrations found today are generally lower than those found in urban lakes or lakes near coal-fired generating plants. Canadian sediment quality guidelines for PAHs since the mid-1980s have only been exceeded in one (fish-free) lake located immediately adjacent to mining, extract and upgrading facilities.
• Pre-development PAH concentrations are typical of wood combustion (probably from forest fires), although PAHs typical of oil sources have increased since oil sands development began.

Metals

• Naturally high sediment loads reflecting erosion during the spring and summer cause total metal concentrations in the Athabasca River to exceed the Canadian Council of Ministers of the Environment (CCME) guidelines in these seasons.
• In almost all samples collected from water, the substance concentrations measured are below relevant environmental guidelines established by the CCME. As well, substance concentrations tend to decrease with increasing distance from oil sands mining and upgrading facilities.
• Hourly average measurements of total gaseous mercury made in Fort McMurray have not shown significant changes over time with concentrations similar to those found elsewhere in Canada.
• Snowpack analysis results show deposition patterns and levels consistent with earlier findings. Concentrations of PAHs and metals (As, Ag, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, Tl, Zn) were highest within 50 km of the major mining extraction and upgrading facilities and fall off with distance.
• Levels of iron and cadmium in some wetlands water samples at several sites exceeded established (CCME) safe limits for aquatic life, but there is no obvious spatial pattern associated with proximity to oil sands upgraders.

Ecosystem impacts

• Athabasca River benthic (organisms that live at the bottom of rivers) communities are diverse and healthy, apparently not showing evidence of biological impairment.
• Zooplankton (tiny invertebrates that float freely throughout freshwater) community studies in lake sediments from the oil sands region show increases in primary productivity of biomass that may indicate climate-induced increases in light and temperature, and/or the addition of nutrients.
• Total phosphorus and nitrogen exceeded the Alberta surface water quality guidelines during periods of naturally high loads of suspended sediment-related precipitation-induced erosion.