 The water is purified using the NEWater technology.With the development of the deep tunnel sewerage system (DTSS) aimed for completion in 2022, sewage will be conveniently transported to the three existing water reclamation plants for treatment.Compelled for the need for self-reliance and sustainability, PUB has invested and developed a dynamic, efficient and sustainable water supply system stemming from four different sources, also known as the Four National Taps.