Newater
A Singapore success story and the pillar of Singapore’s water sustainability, NEWater is high-grade reclaimed water. It is produced from treated used water that is further purified using advanced membrane technologies and ultra-violet disinfection, making it ultra-clean and safe to drink.
Developed by PUB after three decades, NEWater has passed more than 65,000 scientific tests and surpasses World Health Organisation requirements, a testimony of its high quality and reliability.
NEWater is proof that using today's water treatment technologies, water of any quality can be treated into drinking water. It has put Singapore on the world map for innovative water management, including winning for PUB the Stockholm Industry Water Award in 2007.
The first NEWater plants were opened in Bedok and Kranji in 2003. The latest and largest NEWater plant at Changi with a capacity of 50mgd was opened in May 2010. Currently, NEWater meets 30% of the nation’s water needs. By 2060, we plan to triple the current NEWater capacity so that NEWater can meet 50% of our future water demand.
The Singapore Water Reclamation Study (NEWater Study) was initiated in 1998 as a joint initiative between PUB and the Ministry of the Environment and Water Resources (MEWR).
The primary objective of the joint initiative was to determine the suitability of using NEWater as a source of raw water to supplement Singapore's water supply (a practice known as Planned Indirect Potable Use, or IPU). NEWater is treated used water that has undergone stringent purification and treatment process using advanced dual-membrane (microfiltration and reverse osmosis) and ultraviolet technologies.
In 2001, PUB embarked on new initiatives to increase water supply from unconventional sources for non-potable use. Because of its high-grade quality, most of the NEWater are used for wafer fabrication processes, non-potable applications in manufacturing processes as well as air-con cooling towers in commerical buildings, and this has freed up a large amount of drinking water.
Newater technology
NEWater is high-grade reclaimed water produced from treated used water that is purified further using advanced membrane technologies, making the water ultra-clean and safe to drink.
NEWater has passed more than 65,000 scientific tests and surpasses World Health Organisation requirements.
The first stage of the NEWater production process is known as Microfiltration (MF). In this process, the treated used water is passed through membranes to filter out and retained on the membrane surface 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 second stage of the NEWater production process is known as Reverse Osmosis (RO). In RO, a semi-permeable is used. The semi-permeable membrane has very small pores which only allow very small molecules like water molecules to pass through. Consequently, undesirable contaminants such as bacteria, viruses, heavy metals, nitrate, chloride, sulphate, disinfection by-products, aromatic hydrocarbons, pesticides etc, cannot pass through the membrane. Hence, NEWater is RO water and is free from viruses, bacteria and contains negligible amount of salts and organic matters.
At this stage, the water is already of a high grade water quality. The third stage of the NEWater production process really acts as a further safety back-up to the RO. In this stage, ultraviolet or 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 acid-alkali or pH balance, the NEWater is now ready to be piped off to its wide range of applications.
In fact, RO is a widely recognised and established technology which has been used extensively in many other areas. This includes the production of bottled drinking water and production of ultra-clean water for the wafer fabrication and electronics industry. RO is also becoming increasingly popular as one of the technologies used in desalination of seawater for human consumption. It is also used to recycle used water to drinking water on space shuttles and on International Space Stations.
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Plans for Newater
It is safe to use NEWater to supplement our water supply
NEWater is the high grade water produced after treated used water has been further purified using a 3-step process involving advanced membrane technologies like Microfiltration, Reverse Osmosis, and the final disinfection of the product water using ultraviolet light.
The multiple-barrier membrane treatment process has enabled PUB to produce consistently good quality NEWater.
With its consistently good quality and reliability in production, NEWater could be put to greater use in terms of being a source of non-potable water and for indirect potable use by blending it with reservoir water. |
Non-Potable Uses of NEWater
PUB's NEWater initiatives which began in 2001 to increase water supply from unconventional sources has produced good outcomes. Substitution of PUB water with NEWater for non-potable use would free large amount of potable water for other potable purposes. Besides wafer fabrication processes, NEWater can also be used for non-potable applications in manufacturing processes and other industries as well as air-con cooling towers in commercial buildings.
The NEWater Factories at Bedok and Kranji Water Reclamation Plants was commissioned at the end of 2002. Following that since Feb 2003, NEWater has been supplied to wafer fabrication plants at Woodlands and Tampines/Pasir Ris and other industries for non-potable use. In Jan 2004, another milestone in the NEWater initiative was accomplished with the commissioning of the third NEWater Factory at Seletar Water Reclamation Plant which began supplying NEWater to the wafer fabrication plants at Ang Mo Kio. The total initial capacity of the three NEWater factories was 92,000 m3/day or 20 mgd.
In January 2008, PUB awarded the contract for the fifth and largest NEWater plant at Changi. With this addition, NEWater will meet 30% of Singapore’s current water needs by 2010 when the plant is ready.
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Indirect Potable Usage
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NEWater could also be used for indirect potable use by blending with reservoir water . This is nothing new. For over 20 years, several cities in the United States have mixed reclaimed water with reservoir water to supply households. Some of these places include Orange County, outside Los Angeles, Phoenix, Arizona and Fairfax County, north Virginia. In fact, many cities along major rivers in the world like River Rhine, Mississippi River, Yangtze River and Mekong River have also been practicing unplanned indirect potable use of reclaimed water, with upstream water users discharging treated used water into a water source that serves as a water supply for a downstream user. NEWater is also of drinking water standard. |
PUB has received a report from the Panel of Experts studying the suitability of NEWater as a source of water to supplement our water supply. The Panel of Experts concluded that NEWater is consistently of high quality and well within the requirements of the United States Environmental Protection Agency's (USEPA) National Primary and Secondary Drinking Water Standards, and the World Health Organisation's (WHO) Drinking Water Guidelines. The Panel has endorsed NEWater as a safe and sustainable source of water and has supported its indirect potable use in Singapore through storing and mixing with the water in our reservoirs.
PUB has completed its evaluation of the Expert Panel's report and accepted the proposal to use NEWater for indirect potable use. This means mixing and blending NEWater with raw water in the reservoirs before undergoing conventional treatment at the waterworks for supply to the public for potable use. PUB has initially introduced 3 mgd of NEWater (about 1% of total daily water consumption) into our raw water reservoirs. The amount will be increased progressively to about 2.5% of total daily water consumption by 2011.
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NEWater Usage: Industry and Drinking Water
Industry
NEWater is primarily for non-potable industrial uses. Supplied to wafer fabrication, electronics and power generation industries for process use, it is also piped to commercial and institutional buildings for air conditioning cooling purposes. This frees up potable water for domestic consumption. It is delivered via a separate distribution network to industrial and commercial customers.
The demand for NEWater has grown 15-fold from 4 mgd (18,200 cubic metres a day) in 2003 to some 60 mgd (273,000 cubic metres a day) today.
Drinking Water
A small percentage of NEWater is also blended with raw water in the reservoir. The raw water from the reservoir then goes through treatment at the waterworks before it is supplied to consumers as tap water.
External Audit
Twice a year, NEWater undergoes rigorous audit processes by an external audit panel comprising international experts in engineering, water chemistry, toxicology and microbiology.
This high-grade reclaimed water has consistently been awarded top marks for its high quality, safety and for exceeding international standards.
Adapted from pub.gov.sg/water/newater
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