firstly , it will require a shift in thinking so that all sewage that is generated, is trapped and treated. In other words, we cannot afford to distinguish between legal and illegal sewage.
It is only government that can think of people, without sewage. The fact is if there are people, there will be excreta. And if there is excreta, there will be pollution. What we need is to break the sewage drain-hardware approach, so that we can find ways of providing sanitation facilities, as quickly as possible, in all these unserviced areas.
But even as this imperative is met, the pollution plan must begin to trap, intercept and treat all sewage, regardless of colour, caste or creed. This sewage from drains can be transported to the underutilised treatment facilities.
secondly, sewage must be treated as close to the source as possible. This will minimise cost of first transporting sewage for treatment and the conveyance of the treated effluent.
The key pollution lesson is that treated effluent must be reused and recycled and not allowed to be mixed with the untreated in drains. This will require governments to work on a plan to reuse the treated effluents of each plant.
thirdly, as less and less of what is treated makes its way to the drain, the drain with its segregated waste can then be treated at the point of disposal into the river. In other words, what is finally left in the drain must be treated as close to the river, so that the treated effluent is used to dilute the river water and not pollute it.
But all this is only possible if we monitor treated waste and strictly enforce standards. Otherwise, we cannot promote reuse.
The end of the story of Delhi's Yamuna is the beginning of the excreta tales of India. Of more pollution, more sewage. Where people use water, flush it and forget it. Only to drown in their own excreta. Only to degrade their waterways. And only to create more disease and death. If we want a happy ending we must make a new beginning: build a society that learns about its waste so that it can minimise want. A water prudent society. A river worshipping society. Not in the ritual sense, but in the true sense.