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04/07/94 09 51 r:X 916 372 5761 GROL\W1AILR TECH -+->-+ GTI COINCORD co 005/011 <br /> Recove est Analyses <br /> Recovery data were analyzed using the following method as <br />' described by Todd, 1980. <br /> "If a well is pumped for a known period of time and then <br /> shut down, the drawdown thereafter will be identically the <br /> same as if the discharge had been continued and a <br /> hypothetical recharge well with the same flow were <br /> superposed on the discharging well at the instant the <br />' discharge is shut down. <br /> S1 - Q <br />' I (W(u) - W(u' ) l (4 .47) <br /> 47rT <br /> where <br /> U = r2S r2S <br /> and u' (4 . 48) <br /> 4Tt 4Tt' <br /> si 2 .30Q t <br /> log ___. (4 . 47) <br /> 41rT t' <br /> Thus, a plot of residual drawdown s ' versus the logarithm of <br /> t/t' forms a straight line. The slope of the line equals <br /> 2 . 30Q/4AT so that for &s ' , the residual drawdown per log <br /> cycle of t/t' , the transmissivity becomes <br /> T ; 2 . 30Q <br /> (4 . 50) <br /> 47r,6s' <br /> No comparable value of S can be determined by this recovery <br /> test method. <br />