Singapore offers recipes for urban water management
As urbanisation takes over most of the world, management of water can well become the key to survival for a nation. Singapore has become a role-model not only for Asia but for the world as it has combined sound technology with sound management.
How does a small island-nation largely dependent on imported water cope with increasing water demand? Does it impose higher water tariffs on its citizens? Does it invest in new water infrastructure? Does it recycle water?
Singapore is one of the few countries in the world which has a well-thought out policy on water and where policy is implemented with utmost effectiveness. Some of the measures adopted for water management are nothing short of path breaking. Little wonder then, that Singapore is positioning itself as a ‘water hub’ in Asia and is eager to share its experiences with the rest of the region.
Over the years, Singapore has put a robust system in place for meeting its needs of water supply and wastewater disposal. Piped water conforming to international standards reaches the entire population and can be drunk straight from the tap. Until recently, half of the country’s water came from its reservoirs and rainwater collection systems, while the other half was imported from Johor in the neighbouring country Malaysia. Today Singapore has what the government calls “Four National Taps” namely catchment water, imported water from Malaysia, NEWater and desalinated water. PUB is the country’s national water authority responsible for all aspects of water management.
Growing concern in Singapore over the availability of water has led to intensified research into virtually every means to ensure a steady and secure supply. The country with a population of 4.2 million consumes about 300 mgd of water and its needs are growing. The rapidly expanding chemical, petrochemical and wafer fab industries also require more water, which in turn will require huge investments in facilities and technology. A further impetus to the situation has been the uncertainty over the future of long standing water supply agreements with the neighbouring Malaysian state of Johor. These agreements expire in 2011 and 2061.
Singapore builds desalination plant in record time
Although it is seemingly inconceivable that Malaysia would interrupt what is essentially a profitable business for them, Singapore is not taking any chances. One of the new sources of water is a 136,000 m3/day seawater desalination plant that has been inaugurated recently. SingSpring Pte Ltd., a wholly-owned subsidiary of Hyflux Ltd was awarded the Design-Own-Build-Operate (DBOO) contract for this desalination plant. It was constructed in just 20 months, three months ahead of schedule. It is expected that the project will generate S$30-50 million of revenue per annum for Hyflux.
Saudi Arabian Minister for Water and Electricity, Abdullah Al Hussayen who graced the opening of Singapore’s first desalination plant said, “Singapore combines two important aspects of water management – cutting edge technology and superb demand management.” He was all praise for the country’s demand management and especially its ability to control “unaccounted-for-water”, which has set a high standard for the world.
“I can see Asia having the potential to become the hub for exporting desalination to the world. There is a big market for desalination and water reclamation in China, which can be handled in South East Asia and Singapore,” commented Dr Corrado Sommariva, President of the European Desalination Society.
The Singapore desalination plant lays claims to many distinctions:
- The largest RO seawater desalination plant in the tropics
- One of the largest single RO trains in the world
- Efficient boron treatment design to meet stringent boron requirements of less then 0.5ppm
- One of the most energy efficient desalination plants in the world
World class water infrastructure
PUB also has about eight water treatment plants slated for upgrades in the next few years, which might be worth S$20 million each. Non revenue water or unaccounted-for-water is about 5%, one of the lowest in the world. There is 100% metering and PUB has invested in high quality water metering equipment. Legislation and stringent enforcement ensures that illegal water connections are non-existent. There is also an ongoing pipe replacement programme in place.
The last few decades have seen the rapid development of the wastewater infrastructure to serve the development of Singapore. Today, Singapore boasts a world class sewerage system in which 100% of the population is served by modern sanitation. The country has 3200 km of sewers, about 130 pumping stations and six sewage treatment works, with sea outfalls. On 1 April 2001, the six sewage treatment works were renamed Bedok, Jurong, Kim Chuan, Kranji, Seletar and Ulu Pandan Water Reclamation Plants (WRPs) to emphasize their new role of not only treating used water, but also to reclaim water for non-potable use.
Deep Tunnel Sewerage System
Singapore is 100% sewered, but for the country’s visionaries, this is not enough. The country will soon have a Deep Tunnel Sewerage System or DTSS, which will be the most modern and state-of-the-art system that the world has ever seen. Phase I of the project will cost S$3.65 billion. It is all set to transform the management of used water in the island nation.
The DTSS envisages a new conveyance, treatment and disposal system that will eventually route all used water from homes and industries through huge tunnels under the island to two, large, state-of-the-art water reclamation plants located at the two ends of Singapore.
The deep tunnel and link sewers will all have gravity flows, thereby eliminating the need for 130 pumping stations that are operating currently. The new water reclamation plants would render all the existing six water reclamation plants redundant. Including the buffer area surrounding the plants, about 1,000 ha of land will be freed for residential and other developments. And the island will have an odourless environment coupled with cleaner water surroundings.
Closing the water loop – NEWater
Perhaps the greatest environmental initiative taken by Singapore in recent years is Planned Indirect Potable Use (or planned IPU) of wastewater. NEWater is among the latest sources of water which is supplementing Singapore’s water supply. NEWater is treated used water that has undergone stringent purification and treatment process using advanced dual-membrane (microfiltration and reverse osmosis) and ultraviolet technologies.
Water reclamation is not a new concept. In industry, it is quite the norm, even in Singapore. And in the domestic sector, planned indirect potable reuse has been practiced in southern California right from 1976. Water reclamation is a growing trend around the world. Besides, unplanned reuse is going on in practically every major river system in the world today, be it the Mississippi, Rhine, Yangtse or the Ganga. Rivers down the ages have acted as recipients of industrial effluents and domestic sewage from communities, untreated or treated.
Where Singapore scores is in getting public acceptance for reclaiming used water and fast-tracking reclamation projects. Most Asian countries today come under the water-stressed category. Yet their governments do not consider wastewater as a resource. Their talk about reusing wastewater has remained empty rhetoric.
Right from the outset, the Singapore government recognised the need to secure public acceptance for its NEWater project. A comprehensive public education plan was put into operation, where the media played a big role. PUB has set up a NEWater Visitor Centre where visitors can learn about water technology and the experience of water reuse around the world. They can witness first-hand the operation of advanced dual membrane and ultraviolet technologies.
Political observers have commented that more than the spectre of Malaysia turning off its supply of water to Singapore, it was the pragmatic desire of the Singapore government to negotiate from a position of strength that put the NEWater project on the fast track. “NEWater is more than a clean and safe product. It is a strategic concept,” explained Goh Chok Tong, then Prime Minister of Singapore in 2003 when NEWater was launched. “It adds to our water supply by turning every drop of water we get, from, for instance, rainfall, into more than one drop of clean water. It helps us to be self-sufficient in water.” He noted that NEWater would help to take the sensitive issue of water out of the equation of bilateral relations. “Singapore and Malaysia can then focus on mutually beneficial cooperation. Together, we can be a formidable force in economic competition against others, and in addressing other common challenges.”
Whatever be the rationale behind reclaiming wastewater, the fact remains that Singapore’s initiative has aroused keen interest in the rest of Asia, which is facing an explosive increase in demand for water.
“When I think of water and innovation, I think of Singapore,” said Bill Betera, Executive Director, Water Environment Federation in his congratulatory message on the launch of NEWater. “When I think of Singapore, I think of a marriage of technology and understanding applied to a basic human problem and a scarce resource. When I think of Singapore, I think of a model for the rest of the world.”
PUB has introduced 4 mgd of NEWater (about 1% of total daily water consumption) into raw water reservoirs. The amount will be increased progressively to about 2.5% of total daily water consumption by 2011. NEWater is blended and mixed with raw water in reservoirs before undergoing conventional treatment at waterworks and is then supplied to the public for potable use.
“NEWater will be used primarily for non-potable purposes,” according to Mr Goh. “This is not because it is not clean enough for domestic use, but because its ultrapure characteristic can be put to better use in industries such as wafer fabrication which requires ultrapure water,” he said. The switch to NEWater by these industries will free up more reservoir water for drinking.
The NEWater Factories at Bedok and Kranji Water Reclamation Plants with a total production of 15mdg were commissioned at the end of 2002. In Jan 2004, another milestone in the NEWater initiative was accomplished with the commissioning of the third NEWater Factory at Seletar Water Reclamation Plant with a capacity of 5mgd. The 4th NEWater Plant at Ulu Pandan has added another 32 MGD at the beginning of 2007.
The Bedok and Kranji projects were delivered through the conventional ‘build to design’ concept. This involved the engagement of consultants to develop the detailed design of the NEWater factories followed by engagement of contractors to build the factories. The third NEWater project at Seletar, on the other hand was designed and built by the contractor to leverage on the innovation of the private sector.
For the Ulu Pandan NEWater Project, PUB facilitated private sector participation by adopting a DBOO (Design-Build-Own Operate) concept. By involving the private sector in operating and maintaining the NEWater assets, it opens the door for the private sector to provide a wider range of services which were otherwise done in-house by PUB. Such public-private partnerships offer a win-win solution by bringing together the expertise of the public and private sector to meet the needs of the public effectively.
At a recent event, current Prime Minister Lee Hsien-Loong said that Singapore’s four NEWater plants could meet more than 15% of the country’s water demand, well-ahead of the original target of 2010. He said that the Ulu Pandan plant had expanded its capacity from 25 to 32 MGD to meet the increasing demand. Also, he announced the bringing forward of the construction of the fifth NEWater Factory at Changi which would produce 50MGD of water. “Hence by 2011, our NEWater plants will have the combined capacity to meet 30% of Singapore’s water needs, double the original target,” he said.
The Prime Minister also revealed that the ramp-up of NEWater capacity had yielded significant operational efficiencies and economies of scale. “Coupled with the decrease in membrane costs in recent years, we have been able to lower the cost of NEWater from the original S$1.30/ m3 (US$0.86) to S$1.15/ m3,” he said. “From April 1, 2007 PUB will further reduce the price of NEWater from S$1.15/ m3 to S$1.00/ m3.”
A new reservoir in the heart of the city
Another new project on the anvil is the Marina Barrage. To be completed in 2007, this project will bring about three benefits – a new source of water supply, flood control and lifestyle attraction that will offer a host of recreational possibilities.
The barrage which comprises of a series of nine crest gates, will be built across the 350m wide Marina Channel to keep out seawater. With the barrage in place, the Marina Basin will turn into a body of freshwater through natural flushing in one or two years, similar to the existing Kranji and Lower Seletar Reservoir. The freshwater will then be treated using advanced membrane technology to ensure that it is safe for drinking.
Combined with Seletar Reservoir, the new Marina Reservoir will help increase the water catchment areas from half to two-thirds of Singapore by 2009. The Marina Reservoir will meet more than 10% of the country’s water demand.
With sound management practices in place, Singapore is one the few places where water in the public sector has flourished. As urbanisation takes over the world, it becomes important to find technological solutions with small-footprint and capacity for future expansion. Singapore has the highest population density in the world, yet the public does not suffer any inconvenience because the country’s planners have always acted before it got too late.
From a country which used nightsoil removal services as recently as the eighties to a country where state-of-the-art water reclamation is being carried out, Singapore has come a long way in a short time. There is full-cost pricing for water services, a rare phenomenon in Asia. Water conservation, demand management, investment in alternate sources of water such as desalination and reclaimed water – these are often empty catchwords used in Asia. Not in Singapore.