Analyzing the Effectiveness of Water Reclamation Processes in Terms of Costs and Water Quality in Taiwan

The use and promotion of reclaimed water have become global trends and have been widely adopted in countries such as Singapore, Israel, Japan, and the United States. In recent years, Taiwan has also been promoting demonstration plants for reclaimed water by enacting the Reclaimed Water Resources Development Act. Since the demonstration plants apply different reclamation processes, the costs and quality of the reclaimed water vary. This study aims to analyze the cost effectiveness of reclaimed water under three different scenarios, based on operational costs and water quality data from three demonstration plants: the Fongshan River Reclaimed Water Plant, the Shui Nan Water Resource Recovery Center, and the Futian Water Resource Recovery Center. The result shows that the most cost-effective scenario is either the high-cost-high-quality scenario or the low-cost-low-quality one. The moderate scenario is not preferred in terms of cost effectiveness. If the consideration is simply the total cost as a society, the high-cost-high-quality scenario might be preferred. But if “who pays for the cost” is taken into consideration, the low-cost-low-quality scenario is preferred since the cost would be mostly shouldered by the industrial users, rather than the government. The result can not only be used as a reference for the determination of the unified price and water quality standard for reclaimed water in Taiwan in the future but also shed light on the determination of water reclamation processes globally.