Opening of Changi Water Reclamation Plant, the heart of the Deep Tunnel Sewerage System, by Prime Minister Lee Hsien Loong this evening marks an important milestone in Singapore’s water history.
Unknown to many people in the Northern and Eastern parts of Singapore, a mammoth tunnel running 20 to 55 metres underground conveys their used water to a centralised plant in Changi for treatment. This tunnel forms part of the Deep Tunnel Sewerage System (DTSS), a bold project conceived by PUB, the national water agency to collect, treat, reclaim and dispose of Singapore’s used water efficiently and cost effectively.
The completion of Phase One of the DTSS comprises a 48-km deep tunnel which runs from Kranji to Changi, over 60-km of link sewers, two deep sea outfalls and the centralised Changi Water Reclamation Plant (CWRP).
At the heart of the system, the CWRP is a state-of-the-art plant capable of treating 800,000 cu metres (176 million gallons or 320 Olympic size pools) of used water a day. The plant was officially opened by Singapore’s Prime Minister Lee Hsien Loong this evening as one of the highlights of Singapore International Water Week 2009.
“Singapore has enjoyed island-wide modern sanitation since the late 1990s, thanks to the foresight and good planning of the local government. With separate systems for used water and rainwater collection, we have been able to employ large-scale harvesting of rainwater for our water supply needs. The DTSS marks another important chapter in Singapore’s water story as it allows us to embark on the large-scale collection and treatment of used water as well,” said Mr Wah Yuen Long, PUB’s Director for Water Reclamation Plants.
The plant’s benefits are manifold. The centralised treatment of more than half of Singapore’s used water at CWRP leads to economies of scale and will be more cost effective in the long run. The CWRP is also compact, with the various processes stacked up in a multi-storey building.
It sits on a site area of only 32 hectares, one-third the size of a conventional plant. Land occupied by old water reclamation plants and the buffer land surrounding these plants can be freed up for other uses in land scarce Singapore. Being gravity-driven, the system also allows pumping stations to be phased out, freeing up land and eliminating the risk of used water overflows and pollution to catchment water.
The key features of the CWRP include a deep pumping station, a sludge dryer and a covered plant with odour control. It employs cutting-edge technologies which ensure that the processes are environmentally sustainable. For example, bio-gas produced from the water reclamation process is harvested as fuel to dry up the sludge, a semi-liquid residue from the treatment process. This minimises the amount of waste produced by the plant and hence lessens the stress on landfills.
While benefits abound, the most critical part the DTSS plays in Singapore’s integrated water management system is in the supply of NEWater, Singapore’s own brand of high-grade reclaimed water.
Added Mr Wah, “Used water, which is treated to international standards at CWRP, will serve as feedstock for the large-scale production of NEWater. This large-scale collection of used water for treatment and further purification ensures the sustainability of NEWater for generations to come.”
The largest NEWater plant in Singapore is currently being constructed on the rooftop of the CWRP. When completed in 2010, the production of NEWater will be doubled, and this can meet 30% of Singapore's water needs. NEWater is one of Singapore’s Four National Taps and like desalinated water, is not rainfall dependent. It helps Singapore reclaim every single drop of our water through recycling, and is resilient to weather changes.
The mega project saw the involvement of some 300 local and international contractors, subcontractors and suppliers. Through carving out smaller contracts, more companies were able to participate and this in turn promoted a vibrant local industry in Singapore. Many local companies have benefited through participating in this project as they have developed from traditional builders and contractors into higher value and higher skilled system integrators in used water industries. This large and highly visible project has also attracted many multinational companies to show their presence here by supplying their large and specialised equipment for the project. Some have also started to set up design centre and R&D facilities here in Singapore.
The DTSS has been recognised both locally and internationally as an innovative and sustainable solution for cities facing water demand and pollution challenges. The awards for the project include Water Project of the Year at the Global Water Awards 2009 and global winner in the Planning Projects category at the International Water Association (IWA) Project Innovation Awards last year.
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About PUB
PUB is a statutory board under the Ministry of the Environment and Water Resources. It is the water agency that manages Singapore’s water supply, water catchment and sewerage in an integrated way. PUB won the 2007 Stockholm Industry Water Award and was named Water Agency of the Year at the Global Water Awards 2006.
About PUB’s tagline: Water for All: Conserve, Value, Enjoy
PUB has ensured a diversified and sustainable supply of water for Singapore with the Four National Taps (local catchment water, imported water, NEWater, desalinated water).
To provide water for all, PUB calls on all Singaporeans to play our part to conserve water, keep our water catchments and waterways clean and build a relationship with water so we can enjoy our water resources. We can then have enough water for all uses – for industry, for living, for life.
23 June 2009