The main pollution of Chia-Yi City water environment comes from domestic wastewater, which is discharged by seven drainages into Bajhang River and Puzih River respectively. Because the construction of public sewage system takes long time, “Planning and Detail Design for In-Situ Water Purification System of Chia-Yi City in 2012” is planned to solve the water pollution problem recently. According to environment survey and after comprehensive assessment in every relevant factor, although drainage A discharges more pollutants than others, drainage C has high priority in river rehabilitation. The optimal site is the green land at northern part of the Chia-Yi Forestry Culture Park. Two sets of FRP/RC sewage treatment device are needed in the purification system and it will be settled underground. The design capacity is 500 CMD and influent water quality of BOD, SS and NH3-N are 200 mg/L, 30 mg/L and 30 mg/L respectively. Predicted effluent water quality of BOD, SS and NH3-N will be ≦30.0 mg/L, ≦20 mg/L, and ≦12 mg/L respectively. As a result, 86.25 kg/day of BOD, 7.55 kg/day of SS and 9.58 kg/day of NH3-N will be reduced in this treatment system. Construction period will be about 180 days, and the total cost is about NTD 19,798,346.

domestic wastewater;purification