An official of the state government was explaining, at a meeting, the progress made to set up sewage treatment plants, drains and diversionary sewers in pursuit of a Supreme Court order to clean up the Yamuna river in the northern end of Delhi city. A number of planned activities were complete. A lot of money was spent. Impressive. I asked a basic question: "What is the impact of all this on the quality of the river's water?" My question met with silence. Indeed, utter surprise. What did the two tasks have in common?

The real story soon tumbled out. The quality of water had worsened. Every indicator measured by the pollution control board showed that the river had become a more putrid cesspool of the city's waste. In the meantime, three sewage treatment plants were commissioned for this area. Now the facilities were being busily augmented, pumping stations being built to carry the waste. The problem, explained the officials, was that the sewage plants they were showcasing were grossly under-utilised - there was a plant, but no sewage to treat. This, officials pointed out quickly, was not their fault: people living close to the plant were "refusing" to build toilets and take a sewage connection because of the cost involved. Furthermore, there were large numbers of unauthorised - illegal - colonies, which could not be provided sewage connections by law, the officials rued.

If this is the case, what is the solution? Is a sewage treatment plant an adequate answer to polluted rivers? Wouldn't it be better if we began by understanding the sociology and technology of human excreta and sewage management? Should we not examine why people living in wretched conditions - without access to closed drains, living in dirty and unhygienic conditions - would not want a connection to a better life? Studies done in cities show that poor communities are "willing" to pay for better services - clean water and sanitation. Why not here? This is a desperately water-starved area of the city - as are all areas in which poor and illegal settlers live. Should we not, therefore, examine if the sewage connections would demand more water to flush the underground drains, which the administration cannot and will not provide? Also, if wastewater generation - 80 per cent of water supplied is discharged - will double, perhaps triple, would this not make sewage plants ineffective?

Essentially, should we not begin to understand human waste, so that we can understand pollution and its solutions? Unfortunately this, in this deplorably casteist and hierarchical society of ours, is easier said than done. Ours are flush-and-forget mindsets. We can discuss pollution because it is modern and somehow touchable. And we have convinced ourselves that we are not dealing with the untouchable subjects of human excreta and its disposal. Why, otherwise, is there so little research or analysis on different ways of disposing human waste - different ways of building sanitation systems?

In this constipated mindset, sanitation translates into building toilets and drains, with or without water to use. Pollution means building sewage treatment plants - with sewage or without. There is no real interest in finding out whether these approaches work.

Let me now contrast this official meeting with another I attended some weeks ago - in a music hall in a small town in Germany - where some 400 people had gathered to discuss ecological sanitation. The conversation - highly technical and involved - was about building urine-diverting, and other, systems so that nutrients in human excreta could be returned to the land and not pollute waterways. Waste is rich in fertilisers - for every 250 gm of grain consumed, some 7.5 kg of nitrates, phosphorous and potassium is excreted. Human kidneys are nitrogen factories - urine is a cheap and rich source of nitrogen and does not contain pathogens found in faecal waste. Emerging technologies use this understanding to their advantage. They separate out the faecal and urine streams, drastically reduce water consumption, treat and recycle waste to use on the land as compost. The guiding principle is: close the nutrient loop.

This approach is leading to technological innovation - from urine separating dry toilets to highly sophisticated electric and vacuum toilets. Fascinating science. Fascinating technologies. But as I learnt, I realised that the approach is not new. This is the traditional system of waste management - dry human waste composted and reused on the land - that is being revived under a new name.

The problem is that, in India, traditional waste management has dehumanised and degraded the individual handling this task. The problem also is that traditional technology - rudimentary at most times - could be unclean and unsafe. But should we throw the baby out with the bathwater? Clearly, the principles of traditional sanitation - if not its practices - were sound and sustainable. These were built on the extremely modern concepts of recycling and reuse. Is it so impossible to re-engineer the traditional composting toilet for this modern industrial world?

But this would require scientists to think outside the wretched caste system their lives, and minds, are mired in. India has a massive and well-funded scientific paraphernalia. But ask: how many scientists are working on the toilet? None. Not even one.

What we don't seem to realise is that we need a toilet mission before we need a space mission. The choice otherwise is to drown in human faeces. Call it excreta. Call it pollution. Call it whatever you will. Truth is: it stinks and it will kill.

- Sunita Narain