1. A wastewater treatment plant uses rectangular sedimentation tanks for primary clarification. The average design flow is 14,000 cubic meter per day, with a peaking factor of 2.5. Two tanks are used. The length, width, and depth are 24 m, 7 m, and 4 m, respectively. Single effluent weirs are provided at the outlet zone. Calculate the surface overflow rate, detention time, and weir loading rates for the design flow. What happens at peak flow conditions? State regulations specify a minimum detention time of 1 hour.