Desalination plants transform water availability scenario in Singapore-
Significant improvements have been made in the provision of water supply services in Singapore over the past two decades. The entry of private players in the sector has led to an increase in access to water supply and notable reductions in non-revenue water. Although the city-state has no access to freshwater resources, it provides piped water access to all its residents through the implementation of the Four National Taps strategy. Four National Taps refers to enhancement of local catchment water, imported water, reclaimed water and desalinated water.
Currently, about 55 per cent of Singapore’s water demand is met through NEWater (30 per cent), desalination (25 per cent) and local catchment area (20 per cent), and the remaining demand is being met through imports from Malaysia. By 2061, when the import agreement with Malaysia expires, the Public Utilities Board (PUB), Singapore’s national water agency, plans to meet the country’s entire demand through its own resources.
Existing and upcoming desalination plants
Desalination of seawater has been an important component of Singapore’s long-term strategy for water self-sufficiency. There has been a tremendous increase in desalination demand due to industrial growth. Singapore’s market is largely characterised by medium- to large-scale desalination plants that provide potable water for municipal and industrial purposes. At present, the city-state has two desalination plants, at SingSpring and Tuaspring, that can produce 100 million gallons per day (mgd) of desalinated water.
The city-state’s first desalination plant, the SingSpring desalination plant, was commissioned in September 2005. The plant has a capacity to treat 30 mgd (136,380 cubic metres [cum] per day) of seawater. SingSpring Pte Limited, a wholly owned subsidiary of Hyflux Limited, constructed the facility under a design-build-own-operate (DBOO) agreement. Based on the agreement, SingSpring is expected to supply 30 mgd of desalinated water to PUB for a 20-year period.
The second desalination plant, in Tuaspring, which was commissioned in September 2014, is one of the largest in Asia and has twice the capacity of the existing SingSpring desalination plant. This plant is also being operated and managed by Hyflux Limited. The plant has several distinguishing characteristics that make it more cost efficient in comparison to the SingSpring desalination plant. The plant’s compact design has reduced footprint per cum by more than 30 per cent as compared to the SingSpring desalination plant. It also holds the distinction of having one of the largest pretreatment ultrafiltration membrane facilities (318,000 cum per day) in the world. Besides, owing to advanced technology and on-site power generation, the tariff rate of the second Tuas plant is lower than that of the SingSpring plant. In fact, the first-year price for the Tuaspring plant is 0.45 cents per cum, lower than SingSpring’s first-year price of 0.78 cents per cum.
To further ramp up its existing desalination capacity, Singapore is developing another desalination plant in Tuas. The plant will produce about 30 mgd of potable seawater, thus increasing the city-state’s desalination capacity from 100 mgd to 130 mgd. It will deploy the advanced reverse osmosis technology for seawater desalination.
In June last year, PUB invited bids for the construction of the plant through an open tender process. Eight companies evinced interest in developing the plant. At a tender price of S$217 million, the contract for design and construction of the plant was awarded to HSL Constructor Pte Limited.
Unlike the first two desalination plants that are being operated by private agencies under a public-private partnership agreement, the third plant will be owned and operated by PUB. CH2M Hill will supervise the plant’s design and construction, and it is scheduled to begin operations in 2018.
Further, the city-state plans to add another 30 mgd of desalination capacity over the next three to four years. In November 2015, the authority engaged Black & Veatch (SEA) Pte Limited for providing consultancy services for a fourth desalination plant, which will be built at Marina East. The plant will be constructed under a DBOO agreement. Located near water demand zones in the city and eastern Singapore, the Marina East desalination plant will also treat fresh water from the Marina reservoir. Bids for the construction of the plant are likely to be invited in March 2016. The fourth desalination plant is expected to be completed by 2019-20.
Once the third and fourth desalination plants are completed, Singapore will be able to produce up to 160 mgd of fresh water per day from seawater.
Conclusion
The Singapore desalination market is currently on a high-growth trajectory. Industrial estates and commercial buildings are also resorting to desalination plants to meet their water requirements. Moreover, growing urbanisation is paving the way for a greater number of municipal desalination projects. These factors are expected to make desalination an increasingly attractive option to meet potable water requirements. However, increasing energy costs and the relative price of desalinated water will remain key areas of concern for the growth of the segment. That said, as more energy-efficient technologies and equipment are developed, desalination is expected to emerge as a cost-effective alternative to traditional water sources.
