The effluent from sewage treatment plant is fed from one end just below the gravel line and it flows along the length of the pond, takes U turn enters into another pond and flows in reverse direction from where effluent is finally taken to the polished water storage tank. The pond is given a bed slope of 0.5 in 100, filled with 20mm and downsizes granite metal for a depth of 0.6 m from the bottom.