FIELD PUMPING OUT TEST EXAMPLEA pumping out test was carried out on an unconfined aquifer $40$ m thick. Two observation wells were drilled at $15$ m and $30$ m from the pumping well. The original groundwater level before pumping was $5$m below the ground surface.Pumping was carried out until the steady state was reached and the water levels in the observation wells from the surface were found to be $8$ m in the nearer well and $6$ m in the other. If the pumping rate was $0\mathrm{.}25$m$/$ec:

$($a$)$ Calculate the permeability of the aquifer.

$($b$)$ Also determine the radius of influence.

$($c$)$ What would be the drawdown at $20$ m$?$