January 2006 Meeting Abstract
Discharge of Contaminated Groundwater Plumes:
An Overview of Flow and Geochemical Processes at the Groundwater/Surface Water Interface
The Buffalo Association of Professional Geologists (BAPG) is pleased to announce that its monthly dinner meeting will be held at the Millennium Hotel (formerly Four-Points Sheraton) located at 2040 Walden Avenue in Cheektowaga, New York on January 18th,2006. The topic of the dinner presentation and discussion will be “Discharge of Contaminated Groundwater Plumes: An Overview of Flow and Geochemical Processes at the Groundwater/Surface Water Interface” presented by Brewster Conant, PhD. from the University of Waterloo. Dr. Conant’s primary research interest is in the investigation of groundwater/surface-water interactions in rivers and streams and the examination of flow, geochemical, and biodegradation processes affecting the fate and transport of organic compounds passing through the streambed.
The area beneath and adjacent to a stream or lake is potentially a very complex geological, hydrological, and biochemical zone. The transition zone between the groundwater and surface water body (e.g. a streambed) may be spatially and temporally variable and subject to large hydraulic and geochemical gradients. Groundwater contaminant plumes passing through this zone have been shown to change their size, shape, composition, and toxicity as a result of biodegradation, sorption, hyporheic zone mixing, and preferential flow paths. A case study of a tetrachloroethene (PCE) plume discharging to a river illustrates the importance of these mechanisms in a streambed and also shows that benthic and hyporheic zone aquatic life may be exposed to chronic or acutely toxic levels of contaminants even though surface water concentrations are nearly non-detectable. A flux based conceptual model was successfully used as a framework to explain the complex pattern of interstitial water quality, redox and biodegradation observed in the streambed and may be applicable to other sites. The results of the study have important implications for the design of monitoring programs, ecological risk assessments, and the remediation of these types of discharges.
Dr. Brewster Conant Jr. is a Research Assistant Professor (hydrogeologist) in the Department of Earth Sciences at the University of Waterloo. His particular area of interest is in interactions at the groundwater/surface water interface and the examination of flow, geochemical, and biodegradation processes affecting the fate and transport of organic compounds and nutrients passing through it. Dr. Conant received both his M.Sc. (1991) and Ph.D. (2001) in Earth Sciences at the University of Waterloo.
This meeting is a jointly-hosted occasion with the ASCE and SAME, respectively. Due to the large crowd, please RSVP as soon as possible to be assured of a seat.
Michael C. Alfieri
BAPG Executive Vice-President