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

254

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