DJB, the implementing agency in the city for the Yamuna Action Plan, has planned an expenditure of around Rs 4,000 crore for the interceptor project that envisages laying of parallel drains along the three main drains of the city Najafgarh, Shahdara and Supplementary. The parallel drains will intercept the outflow of all small drains that would otherwise meet the main drains, carry the sewage to sewage treatment plants (STP), treat it and only then allow it to flow into the river. ``This includes an 11-year maintenance contract with Engineers India Limited (EIL), the implementing agency for the project. This way we are ensured of quality work,'' said Negi.

There are those who believe that the plan is flawed. Ranjit Kumar, the amicus curiae in the case, told TOI that against an average flow of 2,100 million litres per day (mld), EIL came up with an estimate of 1,600 mld. This too was the dry weather flow and the monsoon flow was much more. ``The maximum flow received in August 2008 was 3,400 mld. Out of 188 drains, the project also talks of intercepting only 107 which would mean that only 1,148 mld of sewage would be carried to STPs instead of 2,207 mld. DJB has accepted in court that only 71% of the drains will be intercepted while 85% of the sewage generated will be treated,'' he said.

This is what DJB claimed in court: ``It's a fact that even this project will not restore the river to Class C bathing quality and it can only be possible if adequate quantity of fresh water is released by the Upper Yamuna River Board.'' The biochemical oxygen demand (BOD) will come down from 41 to 12 but not improve to the required level of 3 mg/l. Negi says that till the time a dedicated sewerage master plan for the city is ready, DJB ``will ensure that sewage is treated to a level of 5-10 mg/l of BOD, against the parameter of 20. All new STPs will be created with this in mind.''

Fresh water flow is not something that can be wished for easily. Rajendra Singh, India's waterman, says that in 1995 five states had signed a treaty to ensure that 10 cumec water from Hathnikund should be released into the river as `ecological flow'. However, the city's growing demand and decreasing groundwater levels have left it entirely dependent on the Yamuna. To make matters worse, the DJB-maintained pipe network is in such a poor shape that the city loses about 54% of its treated water through leakages and pilferage. ``Delhi's per capital consumption of water is much more than the average and most of it is being consumed by the rich. Water should be distributed more equitably. There is no utilisation of waste water either. River and sewer should be kept separate and treatment plants should be decentralised,'' said Singh.

The city does have sewage infrastructure that is not being utilised fully or very intelligently. Delhi has 40% of the total installed sewage treatment capacity in the country despite which the `treated' sewage that enters the river does not meet standards. Common effluent treatment plants are also working under capacity, allowing a massive amount of toxic industrial waste to enter the river unchecked. ``Delhi records about 3,600 mld sewage generation while its treatment capacity is 2,230 mld. Of this, only 1,478 mld is being utilised. At various places, drains carrying treated sewage are met with drains that carry untreated sewage. These are re-treated at another point and put back in the drain where more untreated sewage mixes with it. So much money is being wasted on treating and re-treating the same sewage with no result to show,'' says Sunita Narain, director, Centre for Science and Environment (CSE).

DJB officials contend that the city's population has grown beyond anyone's imagination. Several illegal and unauthorised colonies exist where there is no sewage system. It is in the process of connecting such colonies but that process would take at least a few decades.

``Only about 60% of the city is sewered and most of the waste is going into drains directly,'' said Negi. ``In the present scenario, about 30-35% cannot be sewered at all. We are in the process of coming out with a Master Plan 2031 for sewage which will address this problem. This separately would need an investment of Rs 15,000-20,000 crore. But if we want our system to work, we need an efficient solid waste management system in the city for which other civic agencies would also have to pitch in.''

None of the other agencies has taken its role in cleaning the river seriously either. The high court had mandated creation of 13 enclosures for immersion of idols and pooja samagri but three years down the line, only one has been made.