英文計畫摘要 | Facing the challenges of climate change and the rapid growth of water demand of high-tech industries about to develop in southern Taiwan, this project plans to construct desalination plants in Chiayi, Kaohsiung, and Pingtung to cope with the possible increase in water demand and prevent the instability of water supply from hindering the development of high-tech industries.
In terms of the capacity, Chiayi, Northern Kaohsiung, and Pingtung desalination plants are planned to develop a 100,000 CMD plant with the desalinated water transported to target users; Southern Kaohsiung desalination plant is planned to develop with the capacity of 150,000 CMD, and the desalinated water is used after transported into the allocation system of Fongshan purification plant.
Two stages of assessment are applied in this project and four potential sites are defined, which are Budai site in Chiayi, Hsinta site in Northern Kaohsiung, Daling site in Southern Kaohsiung, and Linbian site in Pingtung.
In the treatment process, coagulation and ultrafiltration are recommended to be the pretreatment process for Chiayi desalination plant due to the high concentration of suspended solid in seawater. The other desalination plants are planned to apply multi-media filter and ultrafiltration as the pretreatment process. one-stage RO is suggested for Southern Kaohsiung desalination plant and two-pass RO is needed for the other desalination plant since the water quality demand of semiconductor industries.
Both seawater intake and discharge pipes are HDPE. The tide condition, wave, current, and ocean topography are all taken into consideration to decide the depth of the intake and outlet facility. The outlet is distant from the intake system at least a kilometer and will be constructed with multi-dischargers.
In the planning of water conveyance, the desalinated water of Chiayi desalination plant is distributed to potential high-tech industries (Yichu, Xiabantian, and Baigecuo) by HDPE pipes with a diameter of 1,200 mm, and the pipe lengths are 9.5, 23, and 31.5 kilometers; the desalinated water of Northern Kaohsiung desalination plant is distributed to Nanzi Technology Industry Park (phase I and III) and Southern Taiwan Science Park Kaohsiung Branch by HDPE pipes with a diameter of 1,200, 900, 700 and 500 mm and totally the pipe length is 26.9 kilometers; the desalinated water of Southern Kaohsiung desalination plant is distributed to Fongshan Water Purification Plant by HDPE pipes with a diameter of 1,350 mm and the pipe length is 10.8 kilometers; the desalinated water of Pingtung desalination plant is distributed to potential high-tech industries (Ailiao and Chienkung) by HDPE pipes with a diameter of 1,200 mm and the pipe lengths are 40.4 and 14.9 kilometers.
The total estimated construction cost of Chiayi Desalination Plant (three potential sites) is approximately NTD 10.256, 11.917, and 13.368 billion respective; the construction cost of Northern and Southern desalination plant is estimated to be NTD 10.812 and 12.071 billion. Total estimated construction cost of Pingtung Desalination Plant (two potential sites) is approximately NTD 13.936 and 10.093 billion respective
The O&M cost mainly consists of energy expense, personnel expense, construction and mechanics, electric appliance renewal and maintenance, chemical expenses, membrane renewal and other expenses. The estimated annual O&M cost for Chiayi Desalination Plant (three potential sites) is approximately NTD 0.761, 0.779 and 0.790 billion; the O&M cost of Northern and Southern Kaohsiung Desalination Plant is estimated to be 0.825and 0.968 billion; the estimated annual O&M cost for Pingtung Desalination Plant (two potential sites) is approximately NTD 0.863and 0.823 billion.
After the analysis of economic benefits, the benefit-cost ratio of Chiayi Desalination Plant (Yichu site) is 1.15, the ratio of Northern and Southern Kaohsiung Desalination Plant is 1.09 and 1.34, and the ratio of Pingtung Desalination Plant is 1.11. |