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October 2000 -32- 003-2191 aquifer transmissivity and storativity; hydraulic conductivity is then calculated by dividing the transmissivity by the aquifer thickness. The analysis yielded transmissivities ranging from about 1.6 to 5.0 squaze feet per day (flr/day). These transmissivitiesequate to hydraulic conductivities ofapproximate1y 0.1 ft/day. Robson (1983) presents estimates of regional hydraulic conductivity for the Dawson aquifer ranging from 0.2 to 3.0 ft/day; thus the site-specific estimates aze considered compazable to the regional estimates given that these values are probably accurate to within about an order of magnitude. The analysis results aze presented on the curve matching graphs in Appendix 5. A potentiometric surface map of the uppermost saturated zone (B Sand) has been prepazed for the property and is shown on Figure 6. This map is based on water levels measured in wells M-1, M-3, M-4, M-5, and M-6. According to the map, groundwater generally flows to the west with a northwest component of flow in the southeast corner of the property. This is roughly the same direction as the slope of the ground surface • topography. The gradient ranges from about 0.02 feet per foot (ft/ft) on the north end to approximately 0.04 ft/ft on the south. Thus, a best estimate of the average gradient for the site would be 0.03 ft/ft. Robson (1983) has estimated a mean porosity for the Dawson aquifer of 32 percent based on laboratory analyses and the interpretation of geophysical logs. The porosity estimates ranged from 18 to 46 percent. Robson (1983) also approximates the mean specific yield of the Dawson to be about 18 percent. The specific yield is roughly equal to the effective porosity. The rate of ground-water flow in the B Sand beneath the site can be calculated using the seepage velocity equation as follows. V001t 1918191 Sed~liWamitl WO doc Sedalia Recycling Center and Depository