South Penghu (contains four main islands: Dongjiyu, Xijiyu, Dongyupingyu, Xiyupingyu) is difficult to build traffic and water resource facilities, since the geological barriors. Running water facilities needs high investment and high operating cost. To date, there is still no running water in Dongyupingyu and Dongjiyu. Islanders rely on groundwater and well water for daily water source. However, groundwater yields limited water volume, and the related facilities are old. The pipe lines have serious leakage and the pumps are old. Factors above will restrict the volume and affect the water quality. Our bureau executed Construction Project of South Penghu Desalination Plant (Dongjiyu and Dongyupingyu) to increase water quality in Dongjiyu and Dongyupingyu. The goal is to provide safe and sufficient running water for local citizens. The desalination Plant finished constructing in October, 2017. The desalination unit passed the acceptance on December 13th after the trial run, and will be officially opened in January, 2018.

Using reverse osmosis, energy recovery and power consumption units, the processed water is qualified according to Tap Water Standard in Taiwan (自來水水質標準). The facility can produce 20 tons of daily use water per day and 3 tons of drinkable water per day. Every pipe line that contacts with seawater is made of stainless steel or anti-salinization and anti-corrosion materials to lengthen expired date. Other design methods are executed according to national standards and laws in Taiwan ROC.

To prevent salt water which produced during desalination impact the coral reef ecosystem, environmental evaluation had been done before the construction. The plant produces 52 tons of salt water per day into the ocean, such as 36 liter per minute. Before emitting, the desalination plant pumps up seawater to dilute the salt water. Our department sampled the seawater and sent it to professional organization for further inspection. The salinity of salt water is 52.7mg/L; salinity of seawater is 31.7 mg/L. By blending salt water with seawater, the salinity becomes 32.1 mg/L. As we sampled the ocean water 20 meter away from the effluent, the salinity is 31.4 mg/L. While the area has good seawater exchange and the desalination emission is extremely low, the salinity of diluted seawater is similar to regular seawater. To sum up, the project affects little to ocean environment.