A representative hydrologic cross section (A-A') was constructed at right angles to the ground-water flow direction to calculate the volume of water flowing through the colluvial aquifer and the mass of exported uranium. The hydraulic gradient calculated for cross section A-A' is 0.009 meter per meter, and the area of the saturated cross section is about 46.4 square meters. Hydraulic conductivity (K) values for the lithology of the colluvial aquifer (mostly clean sand with some silt and gravel) is about 27 meters per day (Freeze and Cherry, 1979). Calculations using this K value indicate that about 11,300 liters per day are flowing through the colluvial aquifer at cross section A-A'. Uranium mass export through cross section A-A' is calculated to be about 43 grams per day.
Hydrologic cross section A-A’. (12k)