INTEGRATED APPROACH TO THREE-DIMENSIONALLY MODELING AN AQUIFER IN ALASKA

Ground water flow and contaminant migration pathways are complicated to infer in aquifers comprised of reworked glacial deposits creating a complex system of juxtaposed hydrogeological facies. The Poleline Road study site, located about two km south of Eagle River, AK, is situated in a topographically low channelised kame deposit surrounded by higher relief kames to the west, north and east, and a large wetland to the south and southwest. The hydrogeology is characterized by glacial deposits of Quaternary age creating a system of interfingering units on an undulating weathered bedrock surface mantling underlying more competent bedrock.

This investigation modeled the glacial deposits at the Poleline Road Disposal Area to provide a three-dimensional framework to assist with remediation decision-making. Site characterization data were acquired from near-surface seismic refraction tomography, DC resistivity surveys, ground penetrating radar profiles, deep borehole drilling, hydrological modeling, and water quality observations. These data were synthesized to develop a conceptual model of local geology in the context of regional record; the conceptual model was then used as the basis to develop a model of subsurface conditions by representing the data in three dimensions using EarthVision software.