How does a city-state that has no natural water body, very little groundwater and even less land to store rainwater quench the thirst of its five million people? Singapore faces this question just as one of its 50-year water import agreement with Johor, now a part of Malaysia, expires in September. After all, the Malaysian import accounts for 40 per cent of Singapore’s total water supply.
The price of water is extremely low with Malaysia not having accounted for inflation in the past five decades. Cheapest among all sources, it stands at one Singapore cent per thousand litres. The city-state charges more than one dollar for the quantity from its people.
Its national water agency, Public Utility Board (PUB), is working overtime to meet its water demand on its own by 2060. It aims to reduce, and possibly eliminate, Singapore’s Malaysian dependence by strengthening its three methods to tap water—treat wastewater, desalinate seawater and maximise collection of rainwater.
Purification processes
The city-state receives 2,400 mm rainfall each year, double the world average. Yet, it is a water-scarce country because of the limited land where water can be stored. PUB is, therefore, making huge investments to develop expensive water sources.
In the 1970s, Singapore started recycling wastewater. A pilot project was launched to treat sewage back to potable water standards. It subsequently built a sewerage network that could help reuse wastewater instead of flushing it into the sea. But the project did not take off because of prohibitive costs. As technology improved, the cost of treatment dipped. In 2002, it reclaimed water from a sewage treatment plant at an additional cost of 30 cents per thousand litres using advanced membranes, filtration and disinfection. It was branded NEWater.
PUB set up five plants which produce more than 530 million litres of water that is almost as pure as distilled water. About 95 per cent of this is used by the IT manufacturing industry which needs purest possible water. The rest is mixed with raw water in reservoirs.
Although the two countries are constantly in talks trying to strike a new deal, PUB opened its second “national tap” in 2005 by treating sea water. This is the most expensive source at 78 cents per thousand litre. But Singapore prefers shelling out a huge amount to depending on Malaysia, fearing political ransom, PUB sources say.
PUB set up a desalination plant that cost US $200 million. The plant can treat 135 million litres of seawater in a day. Another upcoming plant will process more than 300 million litres by 2013. The water agency has identified coastal sites so as to increase the desalination capacity to one billion litres by 2060. Together they will meet 30 per cent of Singapore’s estimated water needs.
By 2060, “we plan to increase desalinated water and NEWater capacity from the present 10 per cent and 30 per cent respectively to 30 per cent and 50 per cent of the total requirement,” says Koh Joh Ting, a PUB official.
Reservoir: the third tap
Singapore built its first reservoir in the mid 19th century. By 2010, the city connected about two-thirds of the country’s surface area—700 square kilometres—to an extensive network of drains and canals that channel storm water to 19 reservoirs. These take care of about 20 per cent of the total water supply.
Treating rainwater even from concrete urban catchments is less expensive than treating waste water or desalinating seawater. The cost differential is kept confidential, perhaps because the country still has two valid agreements with Malaysia (see ‘Contractually bound’).
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