For a small island with no natural groundwater, Singapore’s water self-sufficiency is remarkable. By looking ahead to climate change, the nation has become a global example of sustainable water management. This success is built on two pillars called the ‘deep tunnel sewerage system (DTSS)’ and ‘NEWater’. The DTSS is like an underground highway, using gravity to move used water to centralised reclamation plants. There, it is purified through a rigorous three-stage process to produce ultra-clean NEWater. Acting as a weather-resilient national tap for Singapore, NEWater currently meets up to 40% of the nation’s demand, closing the water dependency and ensuring security during prolonged dry spells.
Singapore’s drinking water highway: what is the DTSS
Imagine a massive ‘highway’ for used water, just 50 metres beneath the bustling streets of Singapore. This is DTSS. As per the report named ‘construction of the deep tunnel sewerage system (DTSS) in Singapore,’ this long-term project replaces an old network of six treatment plants and over 130 pumping stations. By moving the entire process underground, Singapore has successfully reclaimed valuable land for residential and commercial development that would have otherwise been occupied by growing surface-level infrastructure. The tunnels are designed with a slight gradient/slope, allowing used water to flow naturally to centralised reclamation plants without the need of pumping stations. The Changi Water Reclamation Plant (WRP), described by Public Utilities Board (PUB), as one of the most advanced in the world, is built partially underground with facilities ‘stacked’ to maximise space efficiency.
The magic of NEWater: turning used water into drinkable water
The feedstock for Singapore’s high-grade reclaimed water, branded as NEWater, comes directly from these centralised reclamation plants. As per Harry Seah, PUB’s Assistant Chief Executive, NEWater is a pillar of national sustainability. The purification process is a rigorous three-stage journey that makes the water ultra-clean and safe for both industrial and indirect potable use.
- Micro-filtration This first step uses membranes to filter out microscopic particles such as bacteria and some viruses.
- Reverse Osmosis (RO): A semi-permeable membrane allows only water molecules to pass through, holding back contaminants like salts, ions, and organic compounds.
- (UV) Disinfection: The final “safety shot” uses UV light to ensure all remaining organisms are inactivated, resulting in water of such high purity that it exceeds WHO standards.
Image credit: pub.gov.sg
Why Singapore trusts NEWater
‘Is it really safe to drink?’ The data says a YES. A project report outlines that NEWater incorporates 11 distinct safety barriers, ranging from strict source control to natural degradation in reservoirs. To ensure public health, the PUB NEWater Quality report confirms that the water is passed on over 290 parameters. A two-year health study conducted on mice and fish found no adverse toxic or carcinogenic effects from drinking NEWater. To win hearts and minds, PUB has distributed over 16 million bottles of NEWater at national events. An independent survey cited revealed a staggering 98% acceptance rate among the population.
The road ahead for Singapore national water agency
The journey doesn’t end with current successes. PUB is investing 453 million SGD (Singapore dollar) into R&D to reduce the energy footprint of water production. It will also replace older facilities with even more space-efficient rooftop systems, such as the construction of the Changi NEWater Factory 3, to stay ahead of the demand curve while coping with climate change. Through a combination of visionary engineering like the DTSS, cutting-edge membrane technology in NEWater, and an unwavering commitment to R&D, Singapore has turned its water scarcity into a source of national pride. It remains a bold example of how a nation can use technology and public education to make the ‘unthinkable drinkable’.
