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<br /> 5 <br />The modeled area was <br />discretized by 20,000 square <br />cells 100 feet on a side. The <br />top of the model was the land <br />surface as defined by the 3-ft <br />DEM. The model comprised <br />two layers: Layer 1 <br />represented the regolith from <br />the land surface to a uniform <br />depth of 55 feet; and Layer 2 <br />represented the fractured <br />bedrock from the base of the <br />regolith to an elevation of 325 <br />feet, or an approximate <br />thickness of 230 feet. <br /> <br />The initial hydraulic <br />conductivity of the bedrock <br />was set at 0.33 ft/day based on <br />the analyses shown in Table <br />3. The hydraulic conductivity <br />of the regolith was set at 2 <br />ft/day based on our <br />experience with testing of <br />values for the regolith at <br />similar sites. <br /> <br />The effects of the assumed <br />dewatering for the Hanson <br />Quarry at the south edge of <br />the model shown in Figure 5 <br />were simulated using a Drain <br />boundary condition with a <br />constant drain invert <br />elevation of 470 feet and a <br />conductance of 500 ft/day. <br /> <br /> <br />Figure 5.-- Model area and modeled steady state watertable elevations with no pumping from project wells. <br />Recharge to the model was computed using the USDA Soil and Water Assessment Tool (SWAT) model. <br />This model simulates a water balance of the soil zone using daily precipitation as input and outputs by <br />evapotranspiration ET, surface runoff, and deep percolation below the root zone when the soil moisture <br />holding capacity of the soil is exceeded. The deep percolation is routed to the watertable and becomes <br />recharge to the watertable surface. Soil moisture storage capacity used for the model was from the <br />125