REUSING ALL THE WATERSunil Ghorawat
March 2, 2016
With an annual per capita water availability of less than 1970 cubic meters, India is facing the brunt of water scarcity. Rising population and industrial activity is expected to increase water need by nearly 40% as India's water demand rises from the current 750 to 1050 billion cubic meters. This is likely to bring the per capita water availability to less than 1000 cubic meters, making India a water-scarce nation like the Middle East. Water reuse and recycle is the only tenable solution to this problem.
Successful water management is dependent on balancing both supply and demand. Availability of water would determine future economic and social development. The possibility of a third world war resulting from water-related conflict is very real. Increasingly, water is seen a strategic resource - one to be used with caution and managed with care. After all, water availability may be what will differentiate the haves from the have-nots.
Demand management is a better option than augmenting water supply - it is less capital intensive and more environment-friendly. Raw water costs have been drastically increasing in the last few years in many parts of the country. In some areas, the raw water cost is as high as Rs. 60 per cubic meter of raw water. Further, in water scarce areas, industries have no option but to close down their operations if they are using outside water. Industries like Coca-Cola and the Jindal Group have had to endure this problem. Other industries, particularly in South India, like Chennai Petroleum, Madras Fertilizers and GMR Power Corporation have been the pioneers in sewage recycling.
Conserving water and minimizing its use becomes critical, particularly in applications using huge volumes of water. Metering, leakage prevention and monitoring of distribution lines play a key role in this aspect. At a more basic level, applying more water-efficient processes in manufacturing and utilities would help. Finally, the massive scarcity of fresh water implies a need for reusing and recycling used water particularly for less critical applications.
Many industries have realized that the wastewater within their industry might well be the cheapest and most reliable source of water for them. Applications like gardening, landscaping, washing and, particularly, cooling towers consume huge volumes of water which need not necessarily be of very good quality. Recycled water makes ideal sense for usage in these areas.
Today, technology is good enough to produce the highest quality of water, as good as packaged drinking water quality. Still, there is a psychological barrier felt by people to drinking recycled water. Due to this reason, recycled water may be used for other non-potable purposes or be used in groundwater recharge. Singapore has pioneered the concept of NeWater, which talks of recycled water as being absolutely new and pure. The Singapore Public Utilities Board (PUB) has invested heavily on educating and sensitizing the common public on the quality of recycled water. A natural evolution of the same is the concept of Zero Discharge, where industries completely reuse every drop of processed water and nothing is discharged outside the unit.
Reusing sewage for various bulk consumption needs is very important. A case in point is the semiconductor chip industry in Singapore which was a huge consumer of water. Facing major water availability problems, Singapore developed an extensive recycling programme based on membrane technology. A wholistic and integrated approach to managing water demand is essential to manage this resource better for our future generation.
Sunil Ghorawat is Editor-in-Chief, EverythingAboutWater magazine
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