NEWater

Bottles of NEWater for distribution during the National Day Parade celebrations of 2005 at Marina South

NEWater is the brand name given to reclaimed water produced by Singapore's Public Utilities Board. More specifically, it is treated wastewater (sewage) that has been purified using dual-membrane (via microfiltration and reverse osmosis) and ultraviolet technologies, in addition to conventional water treatment processes. The water is potable and is consumed by humans, but is mostly used for industry requiring high purity water.

History

Water recycling in Singapore began in 1974 but the experimental treatment plant was closed a year later due to cost and reliability issues. ^[1]

The Singapore Water Reclamation Study (NEWater Study) was initiated in 1998 by the Public Utilities Board (PUB) and the Ministry of the Environment and Water Resources (MEWR). The aim of this study was to determine if NEWater was a viable source of raw water for Singapore's needs. NEWater and desalination were explored as means to reduce reliance on water imported from Malaysia, which has been a source of friction over the years. Also, while the Malaysian government is bound by two treaties to sell Singapore water until 2011 and 2061, it is under no obligation to do so after these dates.

In 2001, PUB began an effort to increase water supplies for non-potable use. Using NEWater for these applications would reduce the demand on the reservoirs for potable water.^[2]

Production

Singapore has a total of five operational NEWater factories, at Bedok, Kranji, Seletar, Ulu Pandan and a newly opened plant at Changi. The first two were commissioned at the end of 2002, the Seletar plant in February 2004, and the Ulu Pandan plant on March, 2007. For educational purposes, there is a Visitor Centre located within the NEWater factory in Bedok, near the Singapore Expo Tanah Merah MRT Station. ^[3] Entrance into the Visitor Centre is free.

Process

NEWater is the product from a multiple barrier water reclamation process:

• The first barrier is the conventional wastewater treatment process whereby the used water is treated in the Water Reclamation Plants.

• The second barrier, and first stage of the NEWater production process, uses microfiltration/ultrafiltration to filter out suspended solids, colloidal particles, disease-causing bacteria, some viruses and protozoan cysts. The filtered water that goes through the membrane contains only dissolved salts and organic molecules.

• The third barrier, and second stage of the NEWater production process, utilizes reverse osmosis (RO). In RO, a semi-permeable membrane filters out undesirable contaminants such as bacteria, viruses, heavy metals, nitrate, chloride, sulphate, disinfection by-products, aromatic hydrocarbons, and pesticides that cannot pass through the membrane. Hence, NEWater is free from viruses and bacteria and contains very low levels of salts and organic matter. At this stage, the water is already of potable quality.

• The fourth barrier, and third stage of the NEWater production process, acts as safety precaution. UV disinfection is used to ensure that all organisms are inactivated and the purity of the product water guaranteed. With the addition of some alkaline chemicals to restore the pH balance, the NEWater is ready for use.

Applications

At present, the total capacity of the three factories is about 20 million US gallons per day (75,700 m³/day). About 6% of this is used for indirect potable use, which contributes 1% of Singapore's potable water requirements of 380 million US gallons per day (13 m³/s). The rest of the water is used at wafer fabrication plants and other non-potable applications in industries in Woodlands, Tampines, Pasir Ris, and Ang Mo Kio.

Potability

The quality of NEWater consistently exceeds the requirements set by USEPA and WHO guidelines and is, in fact, cleaner than the other sources of Singapore's water.^[4]

Plans are under way to increase the amount of NEWater in indirect potable use up to 3.5% by 2011.

References

1. ^ Lee Poh Onn (2005). "Water Management Issues in Singapore". Centre for Khmer Studies. http://www.khmerstudies.org/download-files/events/Water/Lee%20Nov%202005.pdf. 
2. ^ History of NEWater
3. ^ NEWater Vistor Center
4. ^ Public Utilities Board, NEWater FAQ, accessed 8 Jan 2007.

External links

• Official site
• Groundwater Replenishment System - Orange County, California