November 2005 Meeting Abstract
A Hydrogeochemist’s Perspective on Organic Contaminant Transport in Groundwater
The Buffalo Association of Professional Geologists (BAPG) is pleased to announce that its monthly dinner meeting will be held at Millenium Airport Hotel Buffalo located at 2040 Walden Avenue in Cheektowaga on November 16th, 2005. The topic of the dinner presentation and discussion will be: “A Hydrogeochemist’s Perspective on Organic Contaminant Transport in Groundwater”, presented by Richelle M. Allen-King of the University at Buffalo.
Sediment geochemical (and physical) heterogeneity can cause “nonideal” contaminant transport. The problem is framed by the contrasting transport behavior of perchloroethene (PCE) in two natural gradient field experiments conducted nearby one another in the well-studied Borden aquifer. The PCE retardation factor increased from ~3-6 with time/distance of travel in the Stanford-Waterloo experiment (conducted in the early ‘80s by others) while it was uniform and <2 in the subsequently conducted Emplaced Source experiment. Laboratory measurements show that contaminant sorption is nonlinear and competitive, indicating grain scale chemical heterogeneity. Retardation factor (R) predictions of plume-scale behavior that account for solute and co-solute concentrations using the laboratory-derived sorption parameters are consistent with the behavior of both field plumes. This approach suggests that different R for the two plumes are a consequence of source conditions combined with nonlinear/competitive sorption effects. Further, identified lenses of relatively higher sorption coefficient may contribute to the apparently enhanced dispersion exhibited by the retarded, compared to the non-reactive, solutes.
Richelle M. Allen-King is an Associate Professor at the University at Buffalo. She is the 2003 NGWA Darcy Distinguished Lecturer. Her current research interests include understanding and integrating the basic processes which control the fate and transport of contaminants in the environment, particularly in groundwater. Dr. Allen-King received her PhD in Earth Sciences (Hydrogeology) from the University of Waterloo in 1991. Her specialty is in hydrogeochemistry.
Please RSVP as soon as possible as this meeting has a possibility of filling to capacity.
Michael C. Alfieri
BAPG Executive Vice-President