$(20$ pts$)$ You need to design a circular sedimentation tank for a water treatment plant usi alum as coagulant. Here are some design criteria

Design flow rate: $3$ MGD

Overflow rate: $650gp\frac{d}{f}{t}^2($gpd: gallon per day$)$

Minimum hydraulic residence time: $3$ hours

Please determine the dimensions, actual OFR and HRT for the tank. Use the table below reference

$\backslash$table$[[$Parameter$,$Alum flocs,Iron flocs,Lime$-$soda flocs$],[$Hydraulic residence time, hrs$,4-6,4-6,4-8],[$Overflow rate, $\frac{m^3}{?}$ day $\frac{?}{m^2},20-33,29-41,29-61],[$Overflow rate, gpd$/$ft$2,500-800,700-1,000,700-1,000],[$Weir loading rate, $\frac{m^3}{d}a\frac{y}{m},150-220,200-270,270-320],[$Weir loading rate, gpd$/$ft$,12,000-18,000,16,000-22,000,22,000-26,000],[$Rectangular tanks $($L:W$),2$:$1-4$:$1($all flocs$)],[$Rectangular tanks $($L:D$),10$:$1-20$:$1($all flocs$)],[$Rectangular tanks $($depth$,$ ft $),10-13($all flocs$)],[$Circular tanks $($diameter$,$ ft$),15-250ft($all flocs$)($in increments of $5$ ft $)],[$Circular tanks $($depth$,$ ft$),6-16$ ft $($all flocs$)]]$

Sources: Reynolds and Richards $(1996)$; Mines and Lackey $(2009).$