1. An engineer is asked to design a hydraulically controlled rectangular grit chamber (GC) for a local wastewater treatment plant. The peak flow rate (capacity of the sewer system) is 12,000 m3/day. (a) Provide the special design features for the GC in order to have effective grit removal (10 points). (b) Provide the width (W) and water depth (Z) if a single GC were to be constructed for the intended purpose (8 points). (c) Determine the length of the GC if the average terminal settling velocity of the grit is 0.018 m/s