Closing the Water Loop: Singapore’s NEWater System

Singapore has a land area of about 710 square kilometres and, in PUB’s words, “lacks the space to collect and store all the rain that falls on it”. Even after the catchment was expanded to two-thirds of the island, rainfall and imports alone left the supply exposed to drought and to dependence on a neighbouring country. Water reuse was examined as early as the 1970s, when a government study found reclamation technically possible but rejected it because the technology was then too costly and unproven.

By the 1990s membrane technology had become cheaper and more reliable, and in 1998 PUB set up a team to test it for potable reclamation. A full-scale demonstration plant producing 10,000 cubic metres a day was commissioned in 2000. An international expert panel found the water consistently within WHO and US EPA drinking-water requirements and recommended it for indirect potable use. NEWater was launched to the public on 9 August 2002, when 60,000 people at the National Day Parade toasted with bottled NEWater; the first two plants, at Bedok and Kranji, opened the following year.

Production follows three stages: microfiltration or ultrafiltration (increasingly replaced by membrane bioreactors) removes particles and bacteria; reverse osmosis removes viruses, heavy metals, pesticides and other contaminants; ultraviolet disinfection acts as a final safeguard. Most NEWater does not go to household taps directly. It is piped through a dedicated network to industry — wafer fabrication plants are the largest users — and to cooling systems in commercial buildings. During dry periods it is added to reservoirs, blended with raw water and treated again at conventional waterworks before reaching homes: indirect, not direct, potable reuse. PUB currently lists four NEWater plants in operation. The original Bedok NEWater Factory and its visitor centre closed on 31 July 2024 at the end of their operating life, a reminder that this infrastructure has to be renewed, not just built once.