Evaluating Lower Athabasca River Sediment Metal Concentrations from Alberta Oil Sands Monitoring Programs Using Predevelopment Baselines

• Main Authors: Wynona H. Klemt (10947010), Robert B. Brua (10947013), Joseph M. Culp (10947016), Keegan Hicks (10947019), Brent B. Wolfe (305770), Roland I. Hall (10947022)
• Format: Other Non-Article Part of Journal/Newspaper
• Language: unknown
• Published: 2021
• Subjects: Ecology; Sociology; Inorganic Chemistry; Environmental Sciences not elsewhere classified; Chemical Sciences not elsewhere classified; predevelopment reference conditions; Joint Oil Sands Monitoring Program; JOSM; RAMP; AOSR; Athabasca River; Athabasca River sediment metal moni.; oil sands industry; OSM; sediment metal concentrations; EPA priority pollutants; Regional Aquatics Monitoring Program; predevelopment baselines; source; Alberta Oil Sands Monitoring Programs; oil sands process waters; Athabasca River Sediment Metal Conc.; Alberta Oil Sands Region; Oil Sands Monitoring Program
• Online Access: https://doi.org/10.1021/acs.est.1c01761.s001

Since 1997, sediment metal concentrations have been monitored in the Alberta Oil Sands Region (AOSR) of the Lower Athabasca River by the Regional Aquatics Monitoring Program (RAMP; 1997–2002), the Joint Oil Sands Monitoring Program (JOSM; 2012–2014), and the Oil Sands Monitoring Program (OSM; 2015-present). However, it has remained difficult to differentiate industrial sources from natural sources and quantify the extent of pollution due to inadequate knowledge of predevelopment reference conditions. Here, baselines were constructed using predevelopment (i.e., pre-1967) sediment concentrations of US EPA priority pollutants (Be, Cr, Cu, Ni, Pb) and V, an element elevated in bitumen and associated waste materials, normalized to Al concentration in cores from floodplain and upland lakes within the AOSR to characterize the natural range of variability. The Lower Athabasca River sediment metal monitoring data were examined in the context of the predevelopment baselines. Most metals are below the threshold for minimal enrichment (<1.5x baseline) except for chromium (up to 4.8x) in some RAMP samples. The predevelopment baselines for sediment metal concentrations will be of particular importance as the oil sands industry potentially shifts from a no-release policy to the treatment and release of oil sands process waters directly to the Lower Athabasca River.