Increasing the flow of water from national taps

Feng Zengkun Straits Times 16 Mar 13;

TUCKED away in a laboratory in Jurong East is a team of people who want to ramp up the amount of locally sourced water that flows from your taps in 50 years.

The researchers from Siemens Water Technologies are testing a way to use electrical charges to extract salt from seawater - which could help make it drinkable.

If successful, the project could halve the energy demand of desalination and help increase Singapore's water supply. Seawater is currently treated in a desalination plant in Tuas by forcing it through filters.

The new technology could be ready for use in future treatment plants within two years, said national water agency PUB. In a new report out today on PUB's plans for the next 50 years, the agency called it an example of research that will be "vital" to Singapore's future.

By 2060, PUB said, the country's water usage could double to almost 800 million gallons a day, enough to fill more than 1,200 Olympic-size swimming pools each day.

PUB wants to recycle and treat enough seawater and used water to meet up to 80 per cent of Singapore's domestic and industrial needs by then, up from 40 per cent now.

The goal is important because a year later, one of Singapore's four national taps - imported water from Malaysia - may dry up.

Malaysia's agreement to supply water to Singapore expires in 2061. "If we do not get... the continuation of the water agreement after 2061, we should be ready to assure our own water supply," said PUB chief executive Chew Men Leong.

To do this, PUB will ramp up the flow from the three other national taps: treated rainwater and seawater, and reclaimed used water.

While the goal is ambitious, at least three international experts believe it can be accomplished.

Visiting professor Asit Biswas at the Lee Kuan Yew School of Public Policy, one of three co-authors unveiling a book on Singapore's water history today, said the country had already done the impossible once.

The former president of the International Water Resources Association noted that Singapore had only three reservoirs when it became independent, and could only capture rainwater that fell on 11 per cent of the country's land.

In 1965, the three reservoirs supplied less than 20 per cent of the country's needs. Today, there are 17 reservoirs and rainwater that falls on two-thirds of the island is funnelled into them.

Desalinated water, reclaimed used water and treated rainwater now provide nearly 50 per cent of Singapore's water needs, said Prof Biswas.

He said that according to interviews with former Prime Minister Lee Kuan Yew, Singapore's water future was changed by a single conversation around the time of independence day.

Then British High Commissioner Anthony Head had reported to Mr Lee that unless Singapore behaved as Malaysia wanted, its prime minister Tunku Abdul Rahman could cut off the water supply from Johor to the newborn nation, said Prof Biswas.

Jolted into action, Mr Lee asked engineers to "estimate Singapore's annual rainfall, the technical feasibility to capture every drop, and whether this measure could make the island self-sufficient in water".

To sustain that goal, PUB plans to expand the catchment area to 90 per cent. Theoretically, rainwater can be harvested from the entire island, said PUB director George Madhavan, but this may be too costly.

"It's like squeezing sugar cane. Once you squeeze out most of the juice, you can squeeze more, but it takes a lot of energy," he said.

Singapore has other avenues. Ms Olivia Lum, executive chairman and group chief executive of water treatment company Hyflux, helped introduce one of them. A Hyflux consortium opened Singapore's first seawater treatment plant in Tuas in 2005 and will open another one there this year.

The goal is for treated seawater to meet up to 25 per cent of Singapore's water needs by 2060, up from just 10 per cent now.

But the centrepiece of Singapore's water plan is still Newater, made up of reclaimed used water.

The first two Newater plants were opened in Bedok and Kranji in 2003. There are now two more in Ulu Pandan and Changi.

To make Newater, used water is biologically and chemically treated, filtered through membranes and disinfected using ultraviolet light.

Most of the ultra- clean water is used for industrial processes and to cool air-conditioners because they need highly purified water.

This frees up potable water for households.

PUB wants the home-grown invention to become Singapore's biggest tap by 2060, supplying up to 55 per cent of the country's needs - almost twice the 30 per cent it meets now. This will be done by expanding the capacity of current factories and by building more of them.

But Mr Chew said that Singaporeans - and whether they save or waste water - will write the next chapter of the water story.

Larger role for Newater in meeting nation's future needs
Feng Zengkun Straits Times 16 Mar 13;

NEWATER, or reclaimed used water, will have a bigger role to play in Singapore's water future.

According to a report to be launched today by national water agency PUB, the reclaimed water will meet up to 55 per cent of water demand in 2060, up from the previous projection of 50 per cent.

Treated seawater or desalinated water is expected to meet 20 per cent of the country's water demand by 2030 and up to 25 per cent of demand by 2060, up from 10 per cent now.

The new report today sets out PUB's plans for the next 50 years, and is part of its World Water Day celebrations.

Singapore wants to have the means to produce at least 80 per cent of its own water by 2060.

This is important as the agreement to import water from Malaysia is set to expire in 2061, a year later.

PUB chief executive Chew Men Leong told The Straits Times: "If we do not get... the continuation of the water agreement after 2061, we should be ready to assure our own water supply."

Currently, Singapore can produce at least 40 per cent of its own water needs. Newater contributes 30 per cent of this and treated seawater the other 10 per cent. The rest of the demand is met by imported water and treated rainwater. Singapore is allowed to draw up to 250 million gallons of water from Johor each day. This full quota would meet about 60 per cent of current needs.

Singapore's water demand could double from 400 million gallons a day to almost 800 million gallons a day by 2060, PUB said.

Non-domestic water use, in particular, is set to rocket from 55 per cent of the country's water demand now to 70 per cent by 2060. The rest of the demand comes from homes.

Between now and 2060, PUB plans to build more Newater factories and expand existing capacity to meet up to 55 per cent of demand, up from 30 per cent now. There are currently four Newater plants in Bedok, Kranji, Ulu Pandan and Changi.

Singapore's second desalination or seawater treatment plant will start operations in Tuas this year. The first plant opened in 2005, also in Tuas. The goal is to more than double the tap's capacity from 10 per cent now to 25 per cent by 2060.

PUB also plans to increase the catchment area - where rainwater can be captured and funnelled into reservoirs - from 67 per cent of the island to 90 per cent.

This will be done by building variable salinity plants, which are water treatment plants that can tap smaller streams and rivulets near Singapore's shoreline. The new plants can process brackish rainwater and switch to seawater desalination during dry spells.