A wastewater treatment plant has four primary clarifiers, each with diameter of 15 m and side water depth of 4 m. The aver- age daily flow is 24,000 m/d. The effluent weir is located on the periphery of each tank. Calculate the surface overflow rate, detention time, and weir loading rates. If one tank is taken out of service for maintenance, what happens to the overflow rate and detention time? Is the design adequate for the average flow with the three tanks in service?