Aurora Capping Study – Hydrocarbon Degradation and Mobility

Surface mining of lean oil sands in northern Alberta generates large above-grade landforms containing residual petroleum hydrocarbons (PHCs), presenting potential environmental risks due to their degradation, mobility, and potential release to environmental receptors. This study integrates field experiments and laboratory-based column tests to assess PHC breakdown by microbial activity, methane oxidation, and CO₂ efflux under varying soil and temperature conditions. Technologies used include pore-gas profiling, gas flux measurement systems, temperature-controlled respiration analyses, and finite difference numerical modeling to guide effective landform construction and soil cover design.

The project concluded that petroleum hydrocarbons (PHCs) in lean oil sands overburden degrade through microbial activity, with rates significantly influenced by environmental factors like temperature and soil cover configuration. Gas flux measurements confirmed that soil covers can moderate greenhouse gas emissions and maintain pore-gas conditions supportive of vegetation growth.