There is no consensus on how much wastewater the city generates. cpcb estimates that in 2003-2004, 3,853 mld wastewater was discharged into the river, from the 22-odd drains that traverse the city. However, the Baijal committee in 2004 estimated generation to be 2,960 mld. Given the policy implications of waste, this difference of almost 1,000 mld is simply too massive to ignore.
The fact is that the quantum of waste a city generates is in direct proportion to the water it consumes: at a minimum, 80 per cent of water supplied to a household leaves as waste. In other words, the river's pollution is directly linked to mindless water planning and management in the city.
City planners really do not know how much water the city uses. At present, the city's water demand is about 3,600 mld, it has a capacity to treat 2,880 mld raw water and it officially supplies 3,040 mld of water. This includes 410 mld of officially drawn groundwater, which then adds to the waste stream.
But the water supplied does not reach people. The djb admits that only 1,730 mld water reaches its consumers. It can be assumed then that people have to depend on groundwater aquifers -- tubewells -- for their supplies. But how much groundwater is extracted in Delhi is a mystery. Given the water-waste connection, the mystery deepens as the city hunts for how much sewage it generates.
The fact also is that nobody plans for sewage when they plan for water. For instance, the city government plans to supply another 630 mld of water as soon as Uttar Pradesh releases water from the Tehri dam to the city's Sonia Vihar water treatment plant. In other words, 3,510 mld water treatment capacity will now be available to the city, and each citizen will get 250 litres per capita daily (lpcd). The waste this water will create is still unaccounted for. (see box: all about inequity)
To understand what this profligacy means in waste terms, compare Delhi to other cities of India. According to a cpcb survey, at today's rate of water supply, Delhi contributes 23 per cent of the total wastewater generated by Class i cities (cities with more than 100,000 people). More shockingly, this is 47 per cent of the waste generated by 101 Class i cities and 122 Class ii cities (Population: 50,000-99,999) in the Ganga basin. In other words, all these cities put together generate less than about 50 per cent of what Delhi excretes.
At 3,600 mld of water use, Delhi would generate 2,800 mld of waste, somewhere between the 2,900 mld estimated by djb and cpcb's 3,853 mld estimate. The fact is that the cpcb estimate is based on the flow into the river, while the djb estimate is based on the water it purportedly supplies. The gap -- of 1,000 mld of waste -- is possible based on the use of groundwater in the city as well as the waste it receives from its neighbours. The bottomline is that even as the government is planning full-steam to combat pollution in the river, its agencies do not know how much waste and want there is in the city.
In the late 1970s, many years before the inception of yap, the cpcb had estimated that there were 359 industrial units, which were discharging water effluents. In 2000, cpcb observed that there were 42 industrial units in Delhi directly polluting the Yamuna.
For industrial discharges, too, figures vary significantly with the estimating agency. For instance, in 1994 the Delhi Pollution Control Committee, in its affidavit to the Supreme Court, informed it that 320 mld of industrial waste was discharged into the river. The Baijal committee quoted a study by the National Environmental Engineering Research Institute that industrial wastewater generation in the city is around 180 mld.
By April 2005, the city has 10 common effluent treatment plants with a capacity of 133 mld, set up by the Delhi Small Industries Development Corporation. But only 53 mld of industrial waste reaches these plants.
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.