INFO BULLETIN: Paper outlines impacts of Obed Mountain Mine spill on Athabasca River

Scientists at the Alberta Environmental Monitoring, Evaluation and Reporting Agency (AEMERA) have published an article in the peer-reviewed journal, Science of the Total Environment, which details the immediate and short-term biological and chemical implications of the 2013 Obed Mountain Mine process water spill.

On October 31, 2013, approximately 670,000 cubic meters of coal process water was released into the Athabasca River as a result of the failure of the wall of a post-processing settling pond at the Obed Mountain Mine near Hinton, Alberta.

Results of an emergency monitoring program implemented immediately after the spill by Alberta Environment and Sustainable Resource Development (now Alberta Environment and Parks), indicate that the released plume traveled approximately 1100 km downstream to the Peace-Athabasca Delta in approximately four weeks. The plume initially contained high concentrations of nutrients (nitrogen and phosphorus), metals, and polycyclic aromatic hydrocarbons (PAHs). As a result, some Canadian Council of Ministers of the Environmental (CCME) Guidelines were exceeded in the initial days after the spill. Further analysis revealed elevated concentrations of both metals and PAHs. While toxicity testing of the released material indicated a relatively low or short-lived acute risk to the aquatic environment, some of the water quality and sediment quality variables are known carcinogens and have the potential to exert negative long-term impacts.

The main objectives of the initial monitoring program were to both track and characterize the coal slurry as it flowed downstream, and to perform an initial assessment of the potential environmental impacts resulting from the spill. Samples of water, sediment, soil, and spill material were collected from the Apetowun and Plante creeks, the Athabasca River, and from the mine itself. Samples were analyzed for a range of chemical parameters, with special reference to compounds subject to regulatory limits or requirements.

The full article can be found on the website of the Science of the Total Environment journal:


The Alberta Environmental Monitoring, Evaluation and Reporting Agency (AEMERA) is an arm’s length provincial agency responsible for measuring, assessing and informing policy makers, regulators and the public on the condition of Alberta’s environment on key ambient air, water, land and biodiversity indicators including information necessary to understand cumulative effects.


For more information, please contact:

Melissa Pennell
Director of Communications