$[6]$ Assuming a maximum of $4\mathrm{.}0$ m depth of the sump, and providing $3$ sumps wells such that $2$ wells will always remain in operation when one of the wells is taken under maintenance, design the minimum liquid depth in each well by solving the following questions:

$($i$)$ The surface area of the sump $(m^2).$

$($ii$)$ The diameter of each sump $($m$).$

$($iii$)$The volume of liquid in the well $(m^3).$

$($iv$)$The minimum depth of the well $($m$).$

$[8$ marks$]$