University of Waterloo

Conceptualizing Groundwater/ Surface-Water Interactions: Processes Affecting Discharging Groundwater Contaminants

This seminar will provide a brief overview of how to conceptualize groundwater/surface water (GW/SW) interactions and how they influence contaminated groundwater (GW) discharging to surface water (SW) bodies (i.e., streams, rivers, ponds, lakes, wetlands, and tidally influenced areas). Contaminated GW discharging to SW can adversely impact aquatic life, drinking water quality, and human health, and can be difficult to characterize and evaluate. In contamination studies, characterizing individual flow paths (transport) and the reactions that occur along them is the key to evaluating the fate of the discharging contaminants. General concepts of how GW flows and discharges to different SW bodies on a larger scale will be presented, but it will be shown that the flow, biogeochemical, and biological processes within the much smaller scale transition zone (e.g., streambed and lakebed deposits) between the GW and SW will ultimately determine the impact the contaminated GW will have on the receiving SW body.  Examples of the complexity of these systems and the influence of the transition zone will be presented for solvent, metal, and nitrate GW plumes.  A comprehensive framework for conceptualizing GW/SW interactions will be presented that can be used to develop an understanding these systems and help guide investigations regarding not only water quality issues but also water quantity, and ecosystem issues.

Dr. Brewster Conant Jr. is lecturer in the Department of Earth and Environmental Sciences at the University of Waterloo and has 30 years of experience in hydrogeology and environmental consulting.  He received a B.Sc. in Geology-Physics/Mathematics from Brown University in 1984, and received a M.Sc. and Ph.D. in Earth Sciences at the University of Waterloo in 1991 and 2001, respectively. His main area of expertise and interest is in interactions at the groundwater/surface water interface and the examination of flow, transport, and fate of contaminants passing through it. He has developed innovative field methods, instrumentation, and numerical techniques for assessing groundwater/surface-water interactions using temperature as a tracer and infrared thermography.