A Contract for an office building includes the provision of a storage tank. Drawing No Q₁ shows the plan and Section of the proposed storage Tank. Take off quantities for the following work Topsoil excauation b) Basement excavcition Filling to basement excauation and replacement of topsoil around the structure Specifications 1 lapsoil to be excavated over the area of the structure for a width of 4m all around same and deposited 15m away for re use 2 Top soil to be excavated to a depth of 150mm 3 Excavate for basement including filling around the structure 4 and remove surplus soil from site Filling is to be of selected excavated material 5) Filling around the structure with topsoil 150mm depth NB use CES MM4 2 20.00 STORAGE TANK 30.00 C 13.00 100 FILL 300- 300 TIIVI 300 PLAN SCALE 1:300 20.0원 1.00' 143.001 300 ORIGINAL SURFACE 12M FILL 110M 300 5M 300 SECTION SCALE 1:200 DRAWING No.Q STORAGE TANK

A municipal water treatment plant employs two circular primary clarifiers arranged in parallel, following the bar screen and grit removal chamber. The plant receives 5.0 MGD. Each clarifier is center-fed (water enters at the center and exits at the perimeter). The clarifier radius is 43.0 ft and depth is 10.0 ft. a) What is the hydraulic detention time in each clarifier? b) What is the hydraulic loading rate (critical velocity) in units of ft3/(ft2-hr)?