Recovery test

TM 5-818-5/AFM 88-5, Chap 6/NAVFAC P-418

U.S. Army Corps of Engineers

Figure C-13. Drawdown versus pumping rate for a step-drawdown test.

mined from the drawdown versus distance plots for a

c. Recovery test.

step-drawdown pump test as illustrated in figure

(1) A recovery test may be made at the conclusion

C-14. The difference in drawdown between the ex-

of a pumping test to provide a check of the pumping

tended drawdown-distance curve and the water eleva-

test results and to verify recharge and aquifer boun-

tion measured in the well represents the well-entrance

dary conditions assumed in the analysis of the pump-

loss and can be plotted versus the pumping rate as

ing test data. A recovery test is valid only if the pump-

shown in figure C-15. Curvature of the Hw versus QW

ing test has been conducted at a constant rate of dis-

line indicates that some of the entrance head loss is the

charge. A recovery test made after a step-drawdown

result of turbulent flow into or in the well.

test cannot be analyzed.

U. S. Army Corps of Engineers

Figure C-14. Drawdown versus distance for a step-drawdown test for determining well-entrance loss.

C-13