Information about NEWater

NEWater

1. term coined by the Public Utilities Board (PUB) for high-grade reclaimed water that has been purified with advanced membrane and ultraviolet technologies. 

2. ultra-clean; passed more than 30,000 scientific tests and surpasses the World Health Organization's requirements for safe drinking water. 

3. 3rd "tap" in the "Four National Taps" strategy to provide Singapore with a sustainable and diversified supply of water. (The other three taps are water from local catchments, imported water from Malaysia and desalinated water.)

4. Expected to meet 40% of Singapore's water needs by 2020.

History

1970: Beginning of the use of water reclamation to supplement the existing water supply
1972: First draft of the master plan for water reclamation
1974: First experimental water reclamation plan built in Jurong
1975: Plant was decommissioned due to expensive and reliable water treatment technologies
1998: PUB and the then Ministry of the Environment (ENV) initiated the Singapore Water Reclamation Study, reviving the project (The study showed that the reliability of water treatment technologies had improved greatly and production costs had declined since the 1970s)
2000: Opening of the prototype NEWater plant at the Bedok water reclamation plant
2000 - 2002: Comprehensive study of NEWater conduction; independent expert panel was formed to provide advice on the study, evaluate and make recommendations on the results of the study

The panel concluded that NEWater was safe for potable use but recommended a procedure known as planned indirect potable use, or planned IPU, instead of directly supplying NEWater for potable use. Planned IPU involves blending NEWater with raw reservoir water, and then subjecting the blended water to the same conventional water treatment process as raw reservoir water to produce potable water. There were three reasons for doing this: first, the process would re-introduce trace minerals that had been removed during the production of NEWater; second, reservoir storage would provide additional safety beyond the advanced technologies used to produce NEWater; and third, it would make it easier for NEWater to gain public acceptance.

2003: First NEWater plants, at the Bedok and Kranji water reclamation plants, commissioned and officially opened; NEWater visitor centre also officially opened
2004: Third NEWater plant, at the Seletar water reclamation plant, commissioned and officially opened
2007: Fourth NEWater plan, in Ulu Pandan, officially opened (Unlike the earlier facilities, this was the first to be designed, built, owned and operated by the private sector; also designed and built by Keppel Seghers, supplying 32 million gallons per day (mgd) of NEWater for a period of 20 years)
2008: PUB awarded the contract for the fifth and largest NEWater plant to Sembcorp Industries under the DBOO model
2010: Fifth NEWater plant, at the Sembcorp Industries, officially opened (producing a capacity of 50mgd)

Uses of NEWater

1. supplied mainly for non-potable industrial and commercial uses in wafer fabrication plants, electronics factories and power generation plants. 

2. used in the air-conditioning cooling systems of commercial and institutional complexes.

In addition, NEWater supplements Singapore's potable water supply via IPU. In February 2003, PUB started pumping 2mgd of NEWater into reservoirs for indirect potable use. It aims to increase this progressively to 10mgd or an estimated 2.5% of total potable water consumption by 2011.


NEWater production process

NEWater is the product of a water reclamation process that puts used water through four barriers to become clean water again.


First barrier: Conventional water treatment

The first barrier is the conventional water treatment process where used water is treated to globally recognised standards.


Second barrier: Microfiltration

Microfiltration is the second barrier and the first stage of the NEWater production process. It involves using membranes to filter out suspended solids, colloidal particles, disease-causing bacteria, some viruses and protozoan cysts. The water after microfiltration contains only dissolved salts and organic molecules.


Third barrier: Reverse osmosis

The next barrier is reverse osmosis, also the second stage of the NEWater production process. Here, a semi-permeable membrane traps bacteria, viruses, heavy metals, dissolved salts, disinfection by-products, aromatic hydrocarbons and pesticides. Only very small molecules like water molecules can pass through this membrane to reach the next stage of the process.


Fourth barrier: Ultraviolet disinfection

After reverse osmosis, the water is already ultra-clean. But as an added safety back-up, ultraviolet disinfection is carried out to ensure that any residual micro-organisms are inactivated. This is the third and final stage of the NEWater production process. Chemicals that restore the water's pH balance are then added before the NEWater is deemed ready for use.

http://infopedia.nl.sg/articles/SIP_1555_2009-08-11.html