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42 <br /> t e&-a.ra.5 <br /> calibrated models we have completed in Chatham County as well as USGS and NCGS <br /> reports for similar rock units in the Piedmont. The hydraulic conductivity of the bedrock <br /> was computed using the well yield/ft of well depth and a thickness of 150 feet. <br /> Recharge to the model was set at 4.5 inches/year based on the analysis of stream <br /> baseflows included the USGS report. We note that this value is essentially identical to the <br /> 5 inches/year determined by watershed modeling with 40 years of daily climatic data for <br /> sites we have studied in Chatham County that contain similar vegetation and land use as <br /> the Property. <br /> The performance analysis was conducted for two alternatives to supplying water for the <br /> development: individual wells on each lot or one community well. Figure 5 shows the <br /> drawdown from pumping a community well at a constant rate of 25 gpm and Figure 4 <br /> shows the steady state drawdown computed with the model for pumping from individual <br /> lot wells at a rate of 1 gpm. Based on this analysis the drawdown in individual wells will be <br /> 20 to 40 feet and drawdown in a single community well will be approximately 100 feet. <br /> Using additional community wells would reduce the pumping requirement per well and the <br /> resulting drawdown. <br /> � S - • t v <br /> Maximum drawdown 100 feet <br /> Yf <br /> e - <br /> 4Vj jr, _ .. <br /> Figure 4.--Steady state drawdown in a community well pumping at 25 gpm. <br /> 3 <br />