Water expert S. Vishwanath says that in nature there is no waste, only a misplaced resource
As water shortages increase and groundwater tables fall in our cities and towns, interesting behaviour patterns emerge and consolidate around waste-water. Imagine a farmer cultivating his five acres of land. His borewell which has gone 1000 ft. deep now runs dry because there is no rain and therefore no recharge of groundwater. He sees the city’s sewage water flowing nearby. What should he do? Overcoming his own apprehension he starts to use it on his field. He realizes that the water has nutrients too but they need careful handling since they may burn his crop or destroy his soil. He learns quickly and develops a palate of plants that can tolerate the waste-water and still be productive. He carefully now husbands this resource and makes productive use of it. He grows fodder, he grows maize and he finds a market demand for it. Is he doing the right job?
Imagine another large tank or lake in a city receiving large volumes of untreated waste-water. The Irrigation Department uses it and pumps it into a valley. The water flows down and joins another large but now empty tank. Due to the ecological treatment it receives as it flows, it enters the lake and then goes into ground, and the aquifer improves dramatically. Borewells are now recharged and farmers start to use them. A town which is nearby finds its water resource restored. The borewells are flowing and daily water comes into taps instead of the once in 15 day’s syndrome. Waste water has turned saviour.
A city utility sets up a tertiary treatment plant for its sewage. It treats its waste-water to a high standard and pipes it to industries and an airport for non-potable use. It charges for the treated waste-water and the consumers are willing to pay since they perceive the benefits they receive.
It now moves towards setting up more numbers of tertiary treatment units since a win-win situation is created. Sewage is treated and water is reused.
At an individual home, grey water has been separated from the toilet water. It is then treated in a small filtration unit and then reused for flushing the toilet and for the garden.
Waste-water is seeing a comprehensive relook and many people have started to reuse it in their own way in the situation they are and in the context in which they operate. Farmers use it untreated, Irrigation Departments allow nature to treat it and water utilities use sophisticated treatment systems.
All are relevant and all will see an upsurge in urban India.