From water to water

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Look out of the window the next time you travel by road or by train anywhere in India. Hit a human settlement, and you will see, heaps of plastic coloured garbage apart, pools of dirty black water and drains that go nowhere. They go nowhere because we have forgotten a basic fact: if there are humans, there will be excreta. Indeed, we have also forgotten another truth about the so-called modern world: if there is water use, there will be waste. Roughly 80 per cent of the water that reaches households flows out as waste.

I raise, here, two problems. First, we worry about water and not the waste the water will generate; second, we believe we have a ready solution in the form of (still un-built) sewage treatment plants. Planners worryexcessively, in my opinionabout the water they need to supply to their citizens, but have no clue about the other side of the cointhe waste this water will generate. Sewage, once generated, has to go somewhere. It doesinto streams, ponds, lakes and rivers. It goes into the ground, contaminating the same water people use for drinking. It is no surprise surveys of groundwater find higher and higher levels of nitrate contaminationa sure shot sign of contamination by sewage.

Take two citiesDelhi and Agralocated on the river Yamuna. These cities are looking for water, even as a river passes by them; Delhi is already getting water from the Tehri dam, over 500 km away. Agra, too, is looking to Tehri to meet its thirst. Ironically, it is Delhi which pollutes the Yamuna to such an extent that its downstream neighbour, Agra, finds it difficult to drink the water. Agra must use huge doses of chlorine to clean the water; its planners now contend they will save money if the water comes from the river Ganga upstream.

This is a tragedy; we spin today in a deadly and costly spiral. As surface water or groundwater gets contaminated, the city has no option but to hunt for newer sources of supply. As the search extends, the costs of pumping and supply increase. Most cities today spend anywhere between 50-70 per cent of their water supply budget for electricity to pump water. As the distance increases, the costs of building and then maintaining the water pipeline and its distribution network rise. Worse, if the network is not maintained water losses also increase. Today, municipalities officially report anywhere between 30-50 per cent of the water supplied as lost in leakages. All this means there is less to supply and more to pay.

Add to all this, excreta. We have no national accounts for the excreta we generate or the excreta we treat or do not. Fact is we have no way of really estimating the load of sewage in our cities, because of the different ways in which people source water and the different ways in which people dispose sewage.

Currently, we measure sewage in the most rudimentary fashion: we simply assume that 70-80 per cent of the water officially supplied by municipalities is returned as sewage. The problem is the water-maths isnt accuratewater is supplied but lost; then water is not supplied and households have no option but to depend on groundwater or buy water through private tankers. But all the water used is discharged as sewage, regardless of supply source.

This is also only part of the problem. Currently, the country has installed capacity to treat roughly 18 per cent of the official excreta it generates. But it is well accepted that some of these plants do not function because of high recurring costselectricity and chemicalsor because they do not get any sewage to treat. This is because, like water pipelines, sewage pipelines must be built and then maintained. The fact is most of our cities, old and new, do not have underground sewerage and even if they do, most of the pipes are old and defunct. If all this is put together, then officially the country actually treats 13 per cent of the human excreta it generates. The final blow comes when the partial sewage actually cleaned through expensive treatment gets mixed with the untreated sewage of the majority. This, in a situation, where municipalities are already not recovering the cost of supplying water, forget sewage treatment.

The result is pollution. Incredible India, drowning in its excreta.

Truth is, we cannot catch up with the water we use, the sewage we generate, the sewage we transport and the sewage we actually treat and then dispose of in ditches, lakes or rivers. In any case our rivers have less and less water to assimilate the mess. So we will have to think differently. First, we will have to spend less in bringing water to our houses. In other words, cut the length of the pipeline to reduce electricity and pumping costs and resultant leakage. This means we will have to revive local water bodies and recharge groundwater, so that we can source water from as close as possible. Second, we must use less, not more, water in our homes, so we have less to treat and less to dispose of. Third, we must again cut the costs and transportation of sewageuse existing drain networks and use a variety of technologies to treat sewage as locally as possible. Finally, we must begin to learn, we must re-use every drop of our sewageturn it into drinking water with expensive technology or re-use and recycle it in our gardens, in our industries or use it (after treatment) to recharge our groundwater.

Life is also about re-inventing the cycle of water. Let us understand, therefore, excreta maths: no ashes, no dust, just water to water.

Sunita Narain

Down To Earth
www.downtoearth.org.in