MIL-HDBK-1164
APPENDIX A (Continued)
Metric Static Level, Pumping Level, and Drawdown Calculation
1. Assume a length of air line (L) of 45.7 meters (m). Assume that the pressure gage
reading (P1) before starting the pump is
172 kiloPascals (kPa).
2. Convert pressure to meters of water (A) to determine the height of water above the
bottom of the air line:
4 0147 inch H 2O 0 0254 m
.
.
(A) = 172 kPa
= 17 5 m
.
kPa
inch
3. Calculate the static water level (B) by subtracting the calculated height from the
known air line length:
(B) = L - A = 45.5 - 17.5 = 28.2 m.
4. Assume that the gage reading (P2) during pumping is 124 kPa. Convert this
pressure to meters (C) to determine the height at which water stands in the well
above the bottom of the air line during pumping: (C) = 124 x 0.102 = 12.6 m.
5. Calculate the pumping level (D) by subtracting (C) from the known length of air line:
(D) = L - C = 45.7 - 12.6 = 33.1 m.
6. Determine the drawdown using any of the following methods:
D - B = 33.1 - 28.7 = 4.9 m
A - C = 17.5 - 12.6 = 4.9 m
P1 - P2 = (172 - 124) x 0.102 = 4.9 m
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