A combine sewer is to be designed for a catchment area of 100 hectare. The time of concentration for the area is 25 minutes. The total population of the area is 50000 and the water supply rate is 200 lpcd. If 75% of the water goes into the drain and the impermeability factor for the catchment is 0.6, then the sewer capacity designed to carry three times of average discharge is _____.
1
2.27 m3/s
2
4.62 m3/s
3
2.85 m3/s
4
3.96 m3/s