HR: 09:05h
AN: H31F-05 INVITED     [Abstracts]
TI: Hydrogeophysical Field Characterization at the DOE Old Rifle Site, CO
AU: * Englert, A
EM: alenglert@lbl.gov
AF: Earth Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Hubbard, S
AF: Earth Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Williams, K
AF: Earth Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Chen, J
AF: Earth Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Peterson, J
AF: Earth Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Kemna, A
AF: Agrosphere, ICG IV, Forschungszentrum Jülich, Jülich, 52425, Germany
AU: Spane, F
AF: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, United States
AU: Newcomer, D
AF: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, United States
AU: Long, P
AF: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, United States
AB: Ongoing work within the U(VI)-contaminated alluvial aquifer at the Rifle, CO, Integrated Field Challenge Site (IFC) focuses on investigating the efficacy of biostimulation for facilitating microbial reduction of U(VI) to U(IV). At the site, a series of biostimulation experiments have been conducted within different flow cells by controlled injection of acetate and bromide. Changes in sulfate and dissolved iron and U(VI) concentrations suggested that the system transformations are governed by both chemical and physical heterogeneity of the aquifer at the IFC. Here, we describe the analyses of slug test, flow-meter test, electrical well log, crosshole seismic, radar, and complex electrical resistivity datasets to characterize the hydrogeology of the IFC subsurface. Using a Bayesian approach to integrate the hydrogeological and geophysical wellbore and crosshole datasets, we estimate hydrogeological heterogeneity within, as well as across the different flow cells. The posterior model provides estimates of hydrogeological properties and their associated uncertainties. Moment analyses of the bromide breakthrough data and changes in aqueous sulfate and iron concentrations are used to quantitatively characterize the transport and system transformations as a function of the heterogeneity, both within and across flow cells. The integrated analysis of both estimated hydraulic conductivity field and concentration changes will allow for better understanding of the influence of heterogeneity on stimulated in-situ bioremediation of U(VI) at the IFC.
DE: 0418 Bioremediation
DE: 1040 Radiogenic isotope geochemistry
DE: 1831 Groundwater quality
DE: 1835 Hydrogeophysics
SC: Hydrology [H]
MN: 2007 Joint Assembly