Groundwater monitoring near oil sands development: Insights from regional water quality datasets in the Alberta Oil Sands Region (AOSR)

Abstract

Study region: This study is carried out across a 142,000 km2 area within the Alberta Oil Sands Region (AOSR), Alberta, Canada. Study focus: Groundwater quality data for the AOSR are compiled and interpreted to provide information on regional water quality to inform groundwater monitoring and land use planning. A database of 546 water quality parameters measured between 1958 and 2015 from 5118 water wells is compiled, cleaned, and analyzed by hydrostratigraphic unit (HSU). New hydrologic insights for the region: Baseline water quality conditions were found to vary in the 12 main HSU’s, with wide ranges in total dissolved solids and geochemical facies, reflecting variable lithology and geochemical processes. Median concentrations for multiple parameters exceeded “interim trigger values” under consideration by government regulators. Statistically significant temporal changes in water quality were detected in the 2000’s in isolated areas of Surficial Sands aquifer, the Cretaceous and Devonian formations in the North Athabasca Oil Sands, and in Quaternary aquifers in the South Athabasca Oil Sands and Cold Lake Beaver River. Temporal anomalies occur in areas with enhanced vertical connectivity due to the presence of buried channels, incised rivers, or where the Colorado Group is thin or completely absent. The compiled dataset highlights the role of geochemical data in identifying aquifer connectivity and monitoring priority. Lack of publicly available data for key aquifers near some mining areas are noted.

Keywords

• Groundwater quality
• Oil sands
• Temporal anomalies
• Groundwater monitoring
• Geochemistry