A rectangular primary sedimentation basin is designed for a design average flow of $0\mathrm{.}22$ m$3/$s$.$ The peaking factor is $2\mathrm{.}8.$ The influent BOD$5$ and TSS are $180$ mg$/$L and $220$ mg$/$L$,$ respectively. The design criteria are given below:

$1.$ The design surface overflow rate at design average flow shall be $,36$ m$3/$m$2$d$.$

$2.$ The detention time at design average flow shall be $\mathrm{.}1\mathrm{.}5$ h$.$

$3.$ The water depth at mid$-$length and at design average flow shall be $4\mathrm{.}0$ m$.$

$4.$ The slope of the basin floor shall be at $6\%.$

$5.$ The length$-$to$-$width $($L:W$)$ ratio shall be $4$:$1.$

$6.$ The influent and effluent structures shall be designed for peak wet weather flow.

a$.$ Velocity in the influent channel shall not be $,0\mathrm{.}3$ m$/$s to prevent accumulation of sediments.

b$.$ The influent channel shall have $0\mathrm{.}38$ m diameter submerged circular exit orifices. The velocity through influent orifices shall be $,0\mathrm{.}5$ m$/$s to reduce potential turbulence caused by the jet flows in the inlet zone.

c$.$ The weir loading shall not be $\mathrm{.}340$ m$3/$m$$d$.$