QUESTION $2$ Permeability

a$)$ A pumping test at a rate of $780$ litres $\frac{?}{\text{m}\text{i}\text{n}}$ was done on a well constructed in a

confined aquifer $15$ m thick and overlain by an impermeable layer $10$ m thick.

The initial piezometric surface was $5\mathrm{.}8$ m below ground level for the test well

and observation wells. After the well stabilized the following drawdown levels

$($from ground level$)$ were recorded:

$9\mathrm{.}2$ m in the test well

$7\mathrm{.}9$ m in the observation well $12$ metres from the test well

$6\mathrm{.}3$ m in the observation well $30$ metres from the test well

i$.$ draw a sketch of the well and test wells

$[2$ marks$]$

ii$.$ calculate the permeability of the aquifer

$[3$ marks$]$

iii. estimate the well discharge with the drawdown in the well lowered to

the top of the confined aquifer

$[2$ marks$]$