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Mr. Jeff Van Slooten <br /> Page 3 <br /> Equation B. 4 presents the equation for S rather than Ss, and must <br /> be corrected to perform the proper calculation for the <br /> appropriate storage property. <br /> Single Anisotropic Aquifer Analysis <br /> This section does not adequately explain why the hydrogeologic <br /> regime at the site should be conceptualized as a single <br /> anisotropic aquifer. While anisotropic aquifer analysis is a <br /> reasonable way of analyzing the collected data, the rationale for <br /> foregoing other forms of aquifer analysis is not clearly <br /> presented. <br /> Weeks ' (1969) method is specifically designed to determine the <br /> ratio of horizontal to vertical hydraulic conductivity (Kr/Kz) <br /> for data derived from partially penetrating wells by equating the <br /> actual aquifer to an equivalent isotropic aquifer. The method is <br /> not designed to calculate hydraulic parameters typically obtained <br /> in aquifer test analysis (i.e. , T and S values) . Rather, the <br /> method makes use of the Cooper-Jacob straight-line method to <br /> calculate a T value that is then used as the basis for <br /> establishing the behavior of data that would occur in an <br /> equivalent isotropic system. The eventual calculation of Kr/Kz <br /> is dependent on the Cooper-Jacob-derived T. Therefore, if the <br /> actual data do not adequately lend themselves to straight-line <br /> analysis, then Weeks ' method is not appropriate. <br /> As an illustration of this possibility, Figures B-10 through B-13 <br /> depict Cooper-Jacob analyses of observation wells DSW-7B, -7C, <br /> -1C, and -1D while DSW-4C was pumped. Each of these <br /> time-versus-drawdown plots shows an anomalous increase in <br /> drawdown (or "draw-up") following a steady decline occurring at <br /> least 105 seconds after pumping began. These increases are <br /> disturbing because they make a persistent straight-line slope <br /> determination from late data impossible to achieve. The report <br /> must include an explanation of the data' s behavior in order to <br /> uphold the validity of characterizing the site' s hydrogeologic <br /> regime as a single anisotropic aquifer. <br /> Week' s method allows for the calculation of the ratio of <br /> horizontal to vertical hydraulic conductivity as follows: <br /> Kr/Kz - [r/rc]2 <br /> The equation (which is incorrectly written in the report) makes <br /> use of two radii: r, which is the distance from the pumped well <br /> to an actual observation well, and rc, which is the computed <br />