Singapore, a densely populated island country, lacks natural freshwater sources. The country turns this obstacle into an opportunity, dedicating itself to innovation in the water treatment industry. Harry Seah, director of technology and water quality for PUB, Singapore’s national water agency, discussed with WWD Associate Editor Kate Cline the country’s unique challenges and the technologies it uses to overcome them.
Kate Cline: What is PUB’s role?
Harry Seah: PUB is the national water agency of Singapore and a statutory board under Singapore’s Ministry of the Environment and Water Resources. We manage the entire water cycle in an integrated manner, from rainwater collection to the purification and supply of drinking water, to the treatment of used water and its reclamation into NEWater, Singapore’s own brand of high-grade reclaimed water.
Cline: How does Singapore overcome its lack of natural water sources?
Seah: As a densely populated island city state with 5 million people in a land area of about 700 sq km, Singapore’s main water challenges stem from its lack of land to collect and store rainwater, as well as natural aquifers and groundwater. In the 1960s and 1970s, Singapore faced all the problems of rapid urbanization—polluted rivers, water shortages and widespread flooding.
By investing in water technology and adopting an integrated approach to water management in the last 40 years, PUB has put in place a robust, diversified and sustainable water supply system. Singapore now has four sources of water supply, known as the Four National Taps—water from local catchment, imported water, NEWater and desalinated water.
Cline: What is NEWater? What role does it play in the water supply?
Seah: NEWater is the pillar of Singapore’s water diversification strategy. NEWater is ultra-clean, high-grade reclaimed water produced from treated used water that is further purified using advanced membrane technologies (microfiltration, reverse osmosis and ultraviolet disinfection).
NEWater has passed more than 65,000 scientific tests and exceeds the Environmental Public Health and U.S. Environmental Protection Agency drinking water standards, as well as the drinking water guidelines established by the World Health Organization.
Introduced in 2003, NEWater is primarily supplied to non-domestic sectors, such as wafer fabrication parks, industrial estates and commercial buildings for industrial and air-cooling purposes. A small percentage of NEWater is also mixed with raw reservoir water before being treated at the waterworks for the drinking water supply.
There are currently five NEWater plants, which can meet 30% of our current water needs. The plan is to expand the NEWater capacity so that it meets 40% of Singapore’s water supply by 2020, and the long-term target is to meet 50% of our future water demand by NEWater.
Cline: How is PUB trying to increase water sustainability in Singapore?
Seah: By adopting an integrated approach to water management and investing in water R&D [research and development], we have overcome Singapore’s water challenges and turned our vulnerability into a strategic asset. Moving into the future, we will continue to invest in technology and R&D.
Some new technologies that we are exploring include the membrane bioreactors (MBRs) and variable-salinity plant. The MBR is essentially the coupling of membrane technology with the biological treatment of used water. The result is water for a higher and more consistent quality than that from the conventional treatment process for used water. The variable-salinity plant integrates desalination and NEWater treatment processes to treat water of varying salinity into potable water. It has the potential to increase the water catchment area in Singapore from 67% to 90% by tapping the small rivers and streams.