TM 5-815-5/AFM 88-5, Chap 6/NAVFAC P-418
U. S. Army Corps of Engineers
Figure C-15. Well-entrance loss versus pumping rate for a step-drawdown test.
ratio of log t'/t", where t' is the total elapsed time
(2) When the pump is turned off, the recovery of
since the start of pumping, and t" is the elapsed time
the groundwater levels is observed in the same manner
since the pump was stopped (fig. C-17). This plot
as when the pump was turned on, as shown in figure
should be a straight line and should intersect the zero
C-16. The residual drawdown H' is plotted versus the
(Courtesy of UOP Johnson Division)
Figure C-16. Typical drawdown and recovery curves for a well pumped and then allowed to rebound.
C-14
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