Trace metals in the dissolved fraction (< 0.45 μm) of the lower Athabasca River: Analytical challenges and environmental implications

Developing and applying control charts to detect changes in water chemistry parameters measured in the Athabasca River near the oil sands: A tool for surveillance monitoring

“…The principal components analyses suggest a homogenization of sources of ions in the Athabasca River between locations likely dominated by chemical characteristics of saline groundwater seeps (Jasechko et al ; Gibson et al ). Although change was found in the major ions, similar to other studies (Shotyk et al ), the relationship to any anthropogenic influence is unclear. Changes in major ions likely related to groundwater could be affected by human activities, such as mine dewatering, or by the discharge of effluent from the Fort McMurray municipal wastewater facility (Tondu ; Pilote et al ).…”

“…This is in contrast to results of the principal components analysis at the upstream site, which suggest more heterogeneity in sources of residual error among metals but a closer association between Tl T and TSS. Despite the nuance, general patterns in metals and TSS suggest the addition of materials between locations but also that this material addition was lower in 2010 to 2016 compared with 1988 to 2009. Although most metals generally showed the same patterns, the residual concentrations of Mo T decreased with flow (Supplemental Data, Figure S2) and are predominantly dissolved (Headley et al 2005;Shotyk et al 2017) similar to the major ions. This suggests that Mo T may be predominantly delivered naturally to the Athabasca River via groundwater seeps (Shotyk et al 2017).…”

“…The control chart changes can be used as triggers to focus attention in a tiered monitoring system (Arciszewski et al 2017b). Future studies can be designed to address questions emerging from this and similar work (see Shotyk et al 2017) to improve the detection and understanding of change in the Athabasca River (Arciszewski et al 2017b). Documented long-terms changes in hydrology in the Athabasca River (Squires et al 2010;Bawden et al 2014;Sauchyn et al 2015) and its tributaries (Gibson et al 2016) and climate change (Wu et al 2014;Xia et al 2015) may play a role in the present analyses, as can imprecision in measurements of both independent (i.e., discharge) and dependent (e.g., Tl T ) variables.…”

Using adaptive processes and adverse outcome pathways to develop meaningful, robust, and actionable environmental monitoring programs

“…Any planned development of resources includes an expectation that socioeconomic benefits of the activity will be carefully weighed against any potential environmental costs. Typically, evaluating costs and benefits informs consent of stakeholders and is supported by understanding developed through ecological risk assessments (Munns et al ; Suter et al ), integrated modeling (Hamilton et al ), weight‐of‐evidence approaches (Burton et al ), watershed‐scale assessments (Dubé et al ), experience (Hardman‐Mountford et al ), and other dedicated research activities (Shotyk et al ). Progressively and sequentially reducing the impacts of point and nonpoint stressors on environmental conditions in many localities shows clear evidence of the benefits of these processes.…”

Size-resolved Pb distribution in the Athabasca River shows snowmelt in the bituminous sands region an insignificant source of dissolved Pb

“…These ultra-clean sample collection, handling and analytical procedures have been successfully employed at the SWAMP lab, University of Alberta45. We compare total, particulate (>0.45 μm), dissolved (<0.45 μm), colloidal (1 kDa to 0.45 μm) and mainly ionic (<1 kDa) Pb concentrations in the lower reaches of Athabasca River (AR, ~1500 km) in northern Alberta, one of the largest rivers in Canada (http://www.awc-wpac.ca/).…”