At the turn of the 21st century India prides itself on having an advanced economy, a large educated population with an active space and nuclear programme. However, the country still struggles to provide adequate sanitation and clean water to its poor. Open defecation is widespread as nearly 86% of rural populations do not have access toilets. Though sanitation is perceived to be a rural issue, urban India has its own set of woes. Even in the main metros like Mumbai, sewage is untreated and dumped into water bodies.
The latest UN study shows that unless drastic measures are undertaken, 40℅ of the world's population won't have access to usable water by 2030. A rapidly growing population coupled urban migration, and climate change will compound the issue further. More than 30 million wells and pumps have depleted the groundwater levels posing a serious threat to agriculture and industries.
With an impending water crisis staring right down at them, governments have come to realise the importance of wastewater reuse. The biggest advantage of reusing sewage is that it reduces dependence on freshwater. In this regard, an example worth emulating is that of Singapore. Under a project named NEWater, the country’s Public Utilities Board (PUB) produces high-grade water from sewage. This reclaimed water is then used for potable purposes and by industries that require high-purity water.
It was in the year 1972 that Singapore had come up with a plan for wastewater reuse. By 1974, PUB had developed a pilot plant to convert sewage into water fit for human consumption. Prohibitively high costs and lack of reliable technology forced the board to abandon the idea then. However, it was revived in 1998, and by 2000, Singapore’s first NEWater plant was completed.
Removing the waste from wastewater
NEwater uses a three-stage process for water purification. The first stage is called Microfiltration, the second one is called Reverse Osmosis and the third stage is called Ultraviolet Disinfection. In the first stage, treated wastewater is passed through membranes to filter out the impurities. At the end of this step, the water you get contains only dissolved salts and organic molecules.
In Reverse Osmosis, water from the first stage is passed through a semi-permeable membrane, which further filters out contaminants like bacteria, viruses, and pesticides, to name a few. After this step, the water you get is not only free of pollutants and impurities but also of high-grade quality.
As a final safety back-up and also to guarantee that the water is of the purest quality, ultraviolet disinfection is used. Alkaline chemicals are then added to this water to restore the pH balance before it is supplied for domestic and industrial use.
NEWater has cleared more than 1,00,000 scientific tests and has even surpassed World Health Organisation standards.
On the parameters of colour, clarity, organic substances and bacteria count, NEwater ranks high and is superior to the regular water supplied by PUB.
Making the best of waste
NEWater catapulted Singapore to global acclaim for use of innovative technology while at the same time showing the world how to make the best of waste. The initial NEWater plants started operating in 2003 in Bedok and Kranji. In 2010, another plant was opened at Changi. With a capacity of 50 mgd (million gallons per day), it is the largest NEWater plant in Singapore.
What is commendable is that 30% of Singapore’s water needs are met using reclaimed water. The country plans to ramp up NEWater production so as to meet 55% of its water needs by 2060. It may seem too far-fetched a goal, but certainly not an impossible one.
NEWater can be used for a number of non-potable commercial and industrial purposes. This, in turn, reduces dependence on potable water.
A small quantity of NEWater is also mixed with reservoir water. This is then treated before it starts flowing in the taps of consumers for domestic use. In this way, NEWater successfully meets the rising water needs of industrial and residential consumers without placing stress on Singapore’s water resources.
Leading by example
Singapore won the Environmental Contribution of the Year prize at the Global Water Awards 2008 and has since led the way in water reuse. In an interview to the BBC, Khoo Teng Chye, chief executive, PUB said that NEWater plants were built on a vast scale enabling them to push costs much lower so that the cost of one cubic metre of water has been pushed down to 30 cents (Rs 14).
At a time when many countries are initiating efforts on the water conservation and recycling front, Singapore’s NEWater leads by example. It acts as a case study on how wastewater reuse can go a long way in countering water paucity in a cost effective manner.
Remember, if we are to meet the rising water demands of countries across the world, we need many such NEWater projects. So join the pledge and contribute to better water utilization and distribution.
This is a partnered post.
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Updated Date: Nov 18, 2016 18:20:06 IST