Design a horizontal flow grit chamber for a treatment plant with an average flow of 1.0 × 10 4 m 3 /d and a maximum flow of 3.0 × 10 4 m 3 /d. The grit chamber should remove 0.21 mm particles, have two channels, and handle a flow of 2.00 × 10 4 m 3 d 1 with one channel out of service. The horizontal flow-through velocity will be 0.30 m s 1 . i. Provide a sketch indicating the dimensions of a channel. ii. How much storage will need to be provided for a grit accumulation of 40 m 3 grit/10 6 m 3 wastewater, if grit is to be removed once a week?