Que. A small treatment plant with two filters operates at a filtration rate of 2 gpm/ft2 . The influent TSS is 15 mg/L; the effluent TSS is 0. (a) If each filter is square, 30 ft on a side, calculate the daily volume of water treated (in million gallons/d, MGD) assuming each filter is backwashed once per day in a process that takes 30 minutes. (b) If 3% of the treated flow is used for backwashing, calculate the backwash TSS.