The
island country of Singapore, even since it became independent in 1965
from Malaysian federation, always had one vulnerability; inadequate
availability of water for use of its citizens. Even though there is
substantial rain fall over the island, it has little or limited land
to collect and store rainwater. Authorities in Singapore, realising
that the local catchment water is the main strength of sustainable
water supply, have been making a dedicated effort to increase the
water storage capacity by building new reservoirs.. Since 2011, the
water catchment area has been increased from half to two-thirds of
Singapore’s land surface with the completion of the Marina, Punggol
and Serangoon Reservoirs. Singapore collects rainwater through a
comprehensive network of drains, canals, rivers, storm-water
collection ponds and reservoirs before it is treated for drinking
water supply. This makes Singapore one of the few countries in the
world to harvest urban storm-water on a large-scale for its water
supply.
In
spite of all this effort, the country is still deficient of water and
needs to import water from the Johor state of Malaysia. Singapore has
been importing water under two bilateral agreements. The first
agreement expired in August 2011 and second agreement will expire in
2061. Some elements in Johor are not happy with this arrangement and
keep making noise against the agreements. Singapore has always felt
strategic vulnerability because of this dependence on Malaysia and
has been trying to create alternate additional sources of water.
Singapore
has one of Asia’s largest seawater reverse-osmosis plant, which
produces 30 million gallons of water a day (136,000 cubic metres) to
meet about 10% of Singapore’s water needs. A second and larger
desalination plant with a capacity of 70 million or 318,500 cubic
metres of desalinated water per day, the Tuaspring Desalination Plant
opened in September 2013.
Another
significant step taken by Singapore Government towards self
sufficiency in water is the project to produce high-grade reclaimed
water produced from treated used wastewater that is further purified
using advanced membrane technologies and ultra-violet disinfection,
making it ultra-clean and safe to drink. The project is named as
NEWater and the first plant was opened in 2004. This plant has been
now closed but during last 9 years, 4 new plants were added.
Together, Singapore's four NEWater plants can meet 30% of the
nation’s water needs. Singapore Government wants to expand the
current NEWater capacity by 2060, so that NEWater can meet up to 55%
of future water demand.
However
Singapore's water deficiency is essentially related to non
availability of enough landmass to store water. It gets abundant
rainfall but is unable to retain it. But there are many countries in
the world, which have huge landmass available but water itself is not
available. The port city of Durban in South Africa is one such city
facing acute shortage of water. City's municipality relies on the
Umgeni river system for water. But demand on the system, which
supplies drinking water to about five million people and fuels
industry in the economic hubs of Durban and Pietermaritzburg, a town
66 kilometers from the coast, has outstripped supply for the past
seven years.
To
tide over the difficulty, municipality has been investigating use of
desalination plants as done in Singapore. But these are very
expensive to build and run as an individual plant may cost around
$300 Million. Left with no other option, the city wants to make use
of recycled wastewater like Singapore's NEWater. The city would
upgrade two of its wastewater plants with a three-stage system that
uses filtration, reverse osmosis, ultraviolet light and chlorination
would be used get the water to drinking quality. The treated water
would also be stored and tested before being released. It plans to
mix this purified water with conventional drinking water at a ratio
of 30 percent to 70 percent before supplying it to some parts of the
city. Reusing wastewater in this way, will add 116 megaliters of tap
water to the municipality’s supply daily.
However
people do not like to consume purified wastewater. In Singapore, most
of it is used for industrial consumption. In Durham there has been
opposition to the plan, including the submission of a 5,000-signature
petition from the public. Citizens have raised concerns about the
safety of drinking the reused water. “Recycling of toilet water to
drinking water is a death sentence to the general public because of
health implications,” says one person.
I have
purposely taken here two examples, one from an affluent country and
another from a poor developing economy just to highlight the fact
that in future water is going to be a commodity that would be in
perpetual shortage. In future, many human habitations would be forced
to recycle their wastewater, whether they like it or not.
5th
October 2013
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