How do you design a rectangular sedimentation tank for water treatment?

Design involves: determining flow rate and detention time (typically 2-4 hours), calculating tank volume (V = Q x t), selecting length to width ratio (4:1 to 6:1), keeping depth 3-5m, and maintaining surface overflow rate of 20-40 m3/m2/day. Check horizontal velocity (<0.3 m/min) to prevent scouring. Include inlet baffles for uniform distribution, outlet weirs for even collection, and sludge removal system. Verify Reynolds number for laminar flow conditions.