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• TABLE 61 <br />DRAWDOWN DUE TO LINE SINK AS A <br />FUNCTION OF TIME AND DISTANCE <br />Equation: S = s erfc ( x ) <br />(4at)~ <br />(McWhorter and Sunada, 1977) <br />where: <br />s = drawdown at time t and distance x (ft) <br />so = drawdown at line sink (ft) <br />a = aquifer transmissivity, T, divided by storage coeffi- <br />cient, S (sq. ft/day) <br />t = time since drawdown at line sink was initiated (days) <br />x = perpendicular distance from the line sink (ft) <br />• erfc = complimentary error function <br />assumptions: <br />T = 100 sq. feet/day <br />S = 0.0001 <br />a = T/S = 1,000,000 sq. feet/day <br />calculated drawdown (expressed as function of so) <br />perpendicular distance, x, from line sink (f t) <br />500 2000 10,000 50,000 <br />time in years <br />5 0.98 0.97 0.86 0.41 <br />10 0.99 0.99 0.90 0.56 <br />C <br />Revised 5/22/86 <br />