HR: 11:05h
AN: H42C-04    [Abstracts]
TI: Groundwater Flowpaths Using Isotopic and Geochemical Tracers at a Mine Drainage, Leadville, Colorado
AU: * Liu, F
EM: fliu@ucmerced.edu
AF: University of California, Merced, 4225 N. Hospital Road, Bldg 1200, Merced, CA 95301 United States
AU: Williams, M W
EM: markw@snobear.colorado.edu
AF: University of Colorado, Boulder, CB 450, Boulder, CO 80309 United States
AB: Determining the natural and anthropogenic sources of solutes and contaminants is crucial for watershed mass balance modeling and water resources management. A draining tunnel was constructed in 1952 to dewater mine workings in the Leadville Mining District in Colorado. Since its construction, the physical condition of the tunnel has deteriorated significantly and resulted in blockage and pool-up of ambient groundwater. Presently a 1,000,000,000-galloon pool of contaminated mine water lies under the town of Leadville and is connected to the tunnel. Precise knowledge of groundwater flowpaths is needed to install bulkheads into the tunnel so as to decommission the tunnel without causing catastrophic changes to the mine pool that could flood Leadville with toxic water. Isotopic (O-18 and tritium of water) and geochemical tracers were used in end-member mixing analysis (EMMA) to understand sources and quantity of bedrock groundwater in the tunnel. Conservative tracers were determined by the diagnostic tools of mixing models. A principal component analysis (PCA) was performed to extract eigenvalues and eigenvectors using correlation matrix of conservative tracers. The EMMA results indicated that the tunnel drains only a small volume of mine pool water and a very large volume of bedrock groundwater under current condition.
DE: 1806 Chemistry of fresh water
DE: 1829 Groundwater hydrology
DE: 1040 Isotopic composition/chemistry
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting