NEWater

Bottles of NEWater for distribution during the National Day Parade celebrations of 2005 at Marina South
Bottle of NEWater that was given out during NDP 2014.

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 by industries requiring high purity water.

History

Water recycling in Singapore began in 1974, but the experimental treatment plant was closed a year later because of costs and reliability issues.[1]

In 1998, the Public Utilities Board (PUB) and the Ministry of the Environment and Water Resources (MEWR) initiated the Singapore Water Reclamation Study (NEWater Study). The aim was to determine if NEWater was a viable source of raw water for Singapore's needs. NEWater and desalination both were explored to reduce reliance on water imported from Malaysia, which has long been a source of friction between the Malaysian and Singapore governments.[2] The Malaysian government is treaty bound to sell water to Singapore until 2061, but it has no obligation to do so after that date.[3]

In 2001, PUB initiated efforts to increase water supplies for non-potable use. Using NEWater for these would help reduce the demand on the reservoirs for potable water.[4]

Production

The first NEWater plant was completed in May 2000. In January 2017, a new NEWater plant was launched at Changi, and is the first plant to be jointly developed by a foreign and local company.[5]

Singapore currently has four operational NEWater factories, at Bedok, Kranji, Ulu Pandan and Changi. The Bedok and Kranji factories were commissioned in 2002, the Ulu Pandan plant in March 2007 and the Changi plant in August 2009.[6] A plant at Seletar, commissioned in February 2004, was closed in 2011,[7] as the PUB implemented its plan to centralize the treatment of used water, under the Deep Tunnel Sewerage System.[8]

The Bedok and Kranji plants are operated by the Public Utilities Board, while the Ulu Pandan and Changi plants are under DBOO concessions by Keppel Seghers[9] and Sembcorp Industries[10]

There is a Visitor Centre in the NEWater factory in Bedok, near the Singapore Expo Tanah Merah MRT Station.[11] The visitor centre was awarded the Best Sightseeing/Leisure/Educational Programme at the 20th Tourism Awards 2005 and the IWA Marketing & Communication Award in 2006.[12]

The visitor centre provides multiple free programmes to educate the public regarding the technologies and production of NEWater:

  • NEWater Scientist Program – Students take on the role of NEWater Scientists and explore the visitor centre[13]
  • Outdoor Classroom – Host fun activities and experiments that help students learn about reverse osmosis and other NEWater processes[14]
  • Water Ambassadors – Small workshops that teach uniformed groups (i.e. National Cadet Corps and Scouts Association) skills to be water ambassadors[15]

Procedure

NEWater is produced by a multiple barrier water reclamation process:

  • first stage of the NEWater production process, uses microfiltration/ultrafiltration to remove suspended solids, colloidal particles, disease-causing bacteria, some viruses and protozoan cysts. The filtered water after passing through the membrane contains only dissolved salts and organic molecules.
  • second stage of the NEWater production process, uses reverse osmosis (RO). A semi-permeable membrane filters out contaminants such as bacteria, viruses, heavy metals, nitrates, chlorides, sulfates, disinfection by-products, aromatic hydrocarbons, and pesticides. NEWater is thus free from viruses and bacteria and contains very low levels of salts and organic matter. At this stage, the water is of potable quality.
  • third stage of the NEWater production process, is a safety precaution. UV disinfection is used to ensure that all organisms are inactivated and the purity of the water can be guaranteed. After adding some alkaline chemicals to restore the pH balance, NEWater is ready for use.

Applications

The total capacity of the plants is about 20 million US gallons per day (76,000 m3/d). Some 6% of this is used for indirect potable use, equal to about 1% of Singapore's potable water requirement of 380 million US gallons per day (1,400,000 m3/d). The rest is used at wafer fabrication plants and other non-potable applications in industries in Woodlands, Tampines, Pasir Ris, and Ang Mo Kio.

Government figures show the country's NEWater plans can meet up to 40% of Singapore's current needs, and the figure is expected to go up to 55% by 2060.[16]

Potability

The quality of NEWater consistently exceeds the requirements set by USEPA and WHO guidelines and is cleaner than Singapore's other water sources.[17]

The following table compares the water quality of NEWater to the WHO and USEPA standards.[18]

Quality Chart
Water Quality ParametersNEWaterUSEPA /WHO Standards
A) Physical
Turbidity (NTU)<55/5
Colour (Hazen Units)<515/15
Conductivity (µS/cm)<250Not Specified
pH Value7.0–8.56.5–8.5
Total Dissolved Solids (mg/L)<150500/1000
Total Organic Carbon (mg/L)<0.5-/-
Total Hardness (CaCO3)(mg/L)<50Not Available
B) Chemical (mg/l)
Ammoniacal nitrogen (as N)<1.0-/1.2
Chloride (Cl)<20250/250
Fluoride (F)<0.54/1.5
Nitrate (NO3)<1510/11
Silica<3-/-
Sulphate (SO4)<5250/250
Residual Chlorine (Cl, Total)<24/5
Total Trihalomethanes (as mg/l)<0.080.08/-
C) Metals (mg/l)
Aluminum<0.10.05–0.2/0.2
Barium (Ba)<0.12/0.7
Boron (B)<0.5-/0.5
Calcium (Ca)4 - 20-/-
Copper (Cu)<0.051.3/2
Iron (Fe)<0.040.3/0.3
Manganese (Mn)<0.050.05/0.4
Sodium<20-/200
Strontium (Sr)<0.1-/-
Zinc (Zn)<0.15/3
D) Bacteriological
Total Coliform Bacteria (Counts/100 ml)Not detectableNot detectable
EnterovirusNot detectableNot detectable
Heterotrophic Plate Count (CFU/ml, 35 °C, 48 h)<300<500/-

References

  1. ↑ Lee Poh Onn (2005). "Water Management Issues in Singapore" (PDF). Centre for Khmer Studies.
  2. ↑ Zhang, S.X.; V. Babovic (2012). "A real options approach to the design and architecture of water supply systems using innovative water technologies under uncertainty" (PDF). Journal of Hydroinformatics.
  3. ↑ Chew, Valerie. "Singapore-Malaysia Water Agreements". Singapore Infopedia. Retrieved 23 November 2014.
  4. ↑ History of NEWater Archived 10 June 2013 at the Wayback Machine.
  5. ↑ Boh, Samantha (18 January 2017). "Singapore launches fifth Newater plant at Changi, boosting water supply". The Straits Times. Singapore Press Holdings. Retrieved 8 June 2017.
  6. ↑ The 3rd National Tap Archived 28 May 2016 at the Wayback Machine.
  7. ↑ A Complete Makeover Archived 1 August 2013 at the Wayback Machine.
  8. ↑ "Fact Sheet – NEWater in Singapore" (PDF). Legislative Council of Hong Kong. Research Office, Information Services Division, Legislative Council Secretariat. 26 February 2016. Retrieved 8 June 2017.
  9. ↑ NEWater to supply 30% of Singapore's water needs by 2011: PM
  10. ↑ PUB awards contract for NEWater plant at Changi to Sembcorp
  11. ↑ NEWater Visitor Centre
  12. ↑ "NEWater Visitor Centre".
  13. ↑ "The NEWater Scientist Programme". PUB.
  14. ↑ "Outdoor Classroom". PUB.
  15. ↑ "Wanted: Water Amassadors". PUB. Retrieved 23 November 2014.
  16. ↑ "PUB NEWater". Singapore Public Utilities Board. Retrieved 15 November 2017.
  17. ↑ Public Utilities Board, NEWater FAQ
  18. ↑ "NEWater Quality". PUB. Retrieved 23 November 2014.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.