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Working To Restore Nature By initially assuming a specific capacity and running several iterations of the equation the critical time can be calculated. The critical time for well MW4, equal to 0 75 minutes, is noted on the Jacob plot in Appendix II The significance of determining the critical time is that it confirms that the flattening of the slope of the drawdown curve in the later portion of the test relative to ' early data are a result of casing storage effects as opposed to recharge. The late-time, stable portion of the curve (after approximately 12 minutes) was also disregarded in transmissivity calculations as it appeared that recharge within the zone of influence of the ' pumping well exceeded the rate of discharge of the well This recharge was seen in the observation wells which averaged approximately 0.04' in water level rise during the test. It ' should be noted that delayed yield may have contributed to the flattening of the slope of the drawdown curve after approximately 12 minutes If this is the case, the curve segment used in ' the calculation will have resulted in an underestimation of transmissivity. The transmissivity calculated from the Jacob equation and utilizing Aqtesolv software is 9252 gpd/ft Specific Capacity Method The calculated transmissivity was checked by determining transmissivity according to the specific ' capacity relationship. The theoretical relationship is given by the equation: T = (Q/s) 264 log (0.3Tt/rz S) ' where: T = transmissivity in gpd/ft (estimated from Jacob method) Q = pumping rate in gpm S = drawdown in feet t = elapsed time in days ' r = wellbore radius in feet (assume 0 5') S = coefficient of storage (assume 0 2 for silty sand) ' The casing storage influence was removed from the specific capacity calculation by subtracting the drawdown at the critical time (0 92 ft) from the maximum observed drawdown (1.12 ft). ISMSkREPORTSXCAP-0744 DRF 9