REPORT OF INVESTIGATIONS NO. 38 29
C 1, '1 11 4 1 - 1
EX PL A NATION
ISu W wll equ ed werb pu od well f eld umbed
DO g options pe entlh Pumbove dlstributed e~ily amr aussp Th.t eS, eth well is pumped o!fh I roe of 12.6 0o
conlhnuously entel the dUal wellS, who togettt are
pumped at the taleI of 12 5 gDm conish sly
1~.
Figure 11. Computed drawdown along proposed waterway due to pumping 11.4 million gallons per month from the east and south lines of wells of the Venice well field.
The drawdown for other pumpage rates for these patterns of pumping may be determined easily from figures 9 and 10 because the drawdown is proportional to the pumping rate.
The head differential across the confining beds is equal to the difference between the head at the base of the salt-water wedge and the pumping level of the piezometric surface of the first artesian aquifer. The head at the base of the salt-water wedge was shown to be equivalent to that of a column of ground water extending 0.45 foot above sea level. The pumping level of the piezometric surface after an infinite period of pumping may be estimated by subtracting the computed drawdown (figs. 9, 10, 11) from the design piezometric surface of 5 feet above sea level.
RATE OF SALT-WATER LEAKAGE
The rate of salt-water leakage from the waterway into the first artesian aquifer may be computed from Darcy's law:
Q-= (P'/m') (h') A