How Singapore is leading a water revolution
How Singapore is leading a water revolution
By Alisa Tang
“Sometimes, unfortunately, democracies walk too
slow…”
Erreh Svaia
Taken From: World Economic Forum
Fifty years
ago Singapore had to ration water, and its smelly rivers were devoid of fish
and choked with waste from shipbuilding, pig farms and toilets that emptied
directly into streams.
But it’s a
very different story today. The world’s most densely populated country now
collects rainwater from two-thirds of its land, recycles wastewater and is even
developing technology that mimics human kidneys to desalinate seawater.
“In about a
lifetime, we have transformed Singapore,” said George Madhavan, an engineer who
has worked for the national PUB water agency for 30 years and is now
communications director.
“It’s not
rocket science – it is more political will … The key success factor is really
government – the leadership to pull different agencies together to come up with
a plan.”
As
governments around the world wrestle with water crises from droughts to floods,
many are looking to the tiny Asian city-state of Singapore for solutions.
In many
countries, a flood prevention agency focuses on quickly draining away storm
water, while another manages drinking water.
In
Singapore, PUB “manages the entire water loop”, Madhavan told the Thomson
Reuters Foundation.
Its aim is
to capture every drop of rain it can and recycle as much used water as
possible.
“That means
that ideally, we don’t sell you water. We rent you water. We take it back, we
clean it. We’re like a laundry service. Then you can multiply your supply of
water many, many times,” Madhavan said.
“The water
that you drink today is the same water that dinosaurs drank. We don’t create or
destroy water. It just goes around. So we are using engineering to shorten the
loop.”
Beware of
crocodiles
Following
independence on August 9, 1965, the new 700 sq km country relied on three
reservoirs and water imported from neighbouring Malaysia.
Today, it
collects rainwater through an 8,000-km drain network that empties into 17
reservoirs, and reclaims used water from a deep tunnel sewerage system up to 60
metres below ground.
Singapore,
which is recognised as a global leader in water technology, set up a water
planning unit in 1972. Unlike Bangkok, Kuala Lumpur and Tokyo, it does not have
land outside the city to act as huge catchment areas.
Eleven
government agencies joined up from 1977 to 1987 to clean the heavily polluted
Singapore River and Kallang Basin in the main commercial area.
The city
relocated 610 pig farms and 500 duck farms (later barring such farms),
transferred 5,000 street hawkers to food centres, and moved boats east to the
Pasir Panjang area.
Madhavan
said the biggest challenge was relocating 46,000 squatters living in squalid
conditions without sewers into housing blocks.
More than
260 tonnes of rubbish were removed, the area was landscaped, and in 1987, fish
returned to the waters.
Worried
about pollution, authorities initially kept people away from the waterways.
“We even
had warning signs about crocodiles (which had been spotted in the reservoirs)
to keep people away,” Madhavan said.
Singapore
has since shifted its stance, opening waterfront areas such as Marina
Reservoir, where people kayak, bike and fly kites against a backdrop of the
city’s highrise skyline.
Holy grail
of desalination
Singapore’s
“four national taps” supply 400 million gallons each day for 5.4 million
people.
The
island’s two natural sources are rain and, through an agreement that expires in
2061, up to 250 million gallons per day from Malaysia’s Johor River.
As climate
change makes nature’s sources less reliable, Singapore is focusing on its
reclaimed and desalinated water taps.
NEWater,
introduced in 2003, is the name for used water from the sewerage system,
treated and further purified through microfiltration, reverse osmosis and
ultraviolet disinfection.
Meeting 30
percent of demand, NEWater is potable but mainly used by industries and during
the dry season to top up reservoirs. Singapore aims for NEWater to meet 55
percent of demand by 2060.
The
island’s first desalination plant opened in 2005, and desalinated water meets a
quarter of demand.
Desalinated
water and NEWater are fairly independent of the weather but on the downside,
require more energy to produce, Madhavan said.
Conventional
reverse osmosis requires 3.5 to 4 kilowatt-hours (kWh) to squeeze seawater
through a membrane to make 1,000 litres of freshwater.
Singapore
is now building a demonstration plant to scale up tests on electrochemical
desalting, which uses an electric field to pull salt out of seawater. Madhavan
said PUB hopes to halve energy use.
University
researchers are also developing “the holy grail of desalination” – technology
that imitates the kidneys, he said.
“This will
take some years … They more or less understand how the kidney works to do
desalting. But it’s now how to engineer it, how to build it, the enzymes that
are key to this process.”
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