$8$ N$.$S $8.$ A city is planning the installation of a new water treatment plant to supply a growing population. There will be only one rapid mix basin and then the flow will evenly split between two flocculator trains, each with three basins of equal in volume. The required water depth of all basins is $4\mathrm{.}0$ m$.$ Q $=35$ X $103$ m$3/$day; $=1\mathrm{.}139$ X $10-3$ N$.$s$/$m$2$ in m$2$ ky bzy z gm

$($a$)$ Determine correct basin volumes, dimensions, and required power input using the following

parameters.

Rapid mixing: Time $=2$ min; G $=600$ S$-1$

Flocculator: Time $=30$ min; G $=70$ S$1,50$ S$,30$ S$-1$

$(4$ mark$)$

$($b$)$ Calculate the Monthly alum requirement if the alum dosage is $30$ mg$/$L$.$

$(1$ ma