RECENT ADVANCES IN CHARACTERIZING GROUND-WATER FLOW AND CHEMICAL TRANSPORT IN FRACTURED ROCK: FROM CORES TO KILOMETERS

Fractured-rock aquifers provide water for domestic use, locations for isolating hazardous and toxic waste, and sites for foundations and infrastructure. The dimensions over which the characterization of ground-water flow and chemical transport needs to be conducted for these issues can range from meters to kilometers. Critical to the evaluation of these problems is how formation properties may vary over increasingly larger dimensions. Theoretical methods of scaling formation properties may not be successful in their application to fractured rock, because of the structural complexity and extreme variability in the hydraulic properties of bedrock environments. The influence of the physical dimensions of the problem on the magnitude of formation properties is viewed through the synthesis of laboratory studies, controlled field-scale experiments, and the interpretation of ambient ground-water flow and the spatial distribution of dissolved constituents, gases and isotopes using ground-water flow and chemical-transport modeling.