HR: 0800h
AN: H21E-1078    [Abstracts]
TI: A Dipole Flow In Situ Reactor: Initial Modeling and Experimental Results
AU: * Thomson, N
EM: nthomson@uwaterloo.ca
AF: University of Waterloo, 200 University Ave West, Waterloo, ON N2L 3G1 Canada
AU: Smalley, A
AF: University of Sheffield, Mappin Street, Sheffield, S14JD United Kingdom
AU: McKnight, D
AF: University of Sheffield, Mappin Street, Sheffield, S14JD United Kingdom
AU: Banwart, S
AF: University of Sheffield, Mappin Street, Sheffield, S14JD United Kingdom
AU: Thornton, S
AF: University of Sheffield, Mappin Street, Sheffield, S14JD United Kingdom
AU: Wilson, R
AF: University of Sheffield, Mappin Street, Sheffield, S14JD United Kingdom
AU: Mohamed, M
AF: University of Sheffield, Mappin Street, Sheffield, S14JD United Kingdom
AB: Knowledge of aquifer material characteristics is necessary to make informed decisions about trigger levels for restoration and selecting remediation options. In particular, aquifer property measurement techniques for groundwater transport and reactions are too costly or not-representative of in situ conditions and therefore there is an over-reliance on literature values or model assumptions. This results in overly uncertain predictions of in situ performance and therefore unnecessarily cautious risk assessment and costly remediation strategies. Therefore, cost-effective site investigative tools that have the capability of producing high quality characterization data are required. The dipole flow test which circulates groundwater between isolated injection (source) and extraction (sink) chambers within a single borehole has been used successfully by others to delineate heterogeneous hydraulic properties in both highly permeable and fractured rock aquifers. A project is presently underway that extends this approach by adding a suite of reactive tracers into a dipole flow field to assess various aquifer properties (e.g., geochemical properties and biodegradation potential). If successful this will provide a method to ascertain site-specific parameters for use in appropriate reactive transport models, and to support remedial technology selection and design. This project involves: (1) the construction of a laboratory-scale physical model of a dipole probe to investigate the utility of this dipole flow and reactive tracer test as an site assessment tool; (2) the execution of a host of field trials; and (3) the development of a stand-alone multi-phase reactive transport model that can be used to interpret the generated breakthrough curves. In addition to an overview of this project, initial experimental and model results will be discussed.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting