The Sisamau Nala — often referred to as the ‘largest drain in Asia’ — was being used as a sewerage conveyance channel since the 1890s.
But now with many STPs in functional mode, the waste is being tapped and treated before it flows into the Ganga.
Ganga’s most polluted stretch in its journey from Gaumukh to Gangasagar is in Kanpur. And that’s no surprise — the city generates over 450 million litres of municipal sewage and industrial effluent daily and a majority of it was flowing directly into the Ganga until recently.
Around 140 million litres of waste, mostly domestic sewage but also untreated waste water from slaughter houses in Fazalganj, was flowing into the holy river through just one drain, the Sisamau Nala.
The drain, often referred to as the “largest drain in Asia”, was being used as a sewerage conveyance channel since the 1890s. A network of multiple tributary drains with a total length of approximately 13 km, the Sisamau Nala was fully tapped and diverted to sewage treatment plants (STPs) in the city in 2018.
Later today, Prime Minister Narendra Modi, who is in Kanpur to hold the first meeting of the National Council for Ganga, will inspect the arrangements made to divert the drain as he commutes by boat from Atal Ghat to Sisamau Nala.
The drain’s diversion, completed in 2018, was done in two stages.
In the first stage, the drain was intercepted at Bakar Mandi. Around 80 million litres of sewage is tapped here daily and is pumped through the Rakhi Mandi Pumping Station to the Bingawan STP, which has a treatment capacity of 210 million litres daily (MLD).
In the second stage, the drain has been intercepted closer to the Ganga, at VIP Road. Around 60 million litres of sewage is tapped here daily and pumped to a STP in the city’s Jajmau area through the newly built RSPH Pumping Station.
As a result, nearly 140 MLD of sewage, which was flowing into the Ganga untreated, is now being treated before disposal. This has not only freed the river of some sewage but has also ensured that the existing treatment capacity in Kanpur is put to good use.
Much of the nearly 457 MLD treatment capacity in Kanpur was under-utilised as not enough sewage reached the three existing STPs (Jajmau-205 MLD, Bingawan-210 MLD and Sazari-42) MLD in the city. This is because, according to the Jal Nigam, only 39 per cent of the city is connected to the sewage system.
According to the 2011 census, Kanpur — the city which dumps the most untreated waste water into the Ganga — has over 5.5 lakh properties. The Kanpur Nagar Nigam says that only 1.76 lakh of these, a little over 30 per cent, were linked to the sewer network by 2013. Waste water from the remaining properties was flowing directly into the Ganga.
The under-utilisation of existing STPs isn’t unique to Kanpur. In a 2013 report, the Central Pollution Control Board states that less than 60 per cent of the capacity was put to use in 51 out of 64 STPs in Ganga’s catchment.
For better utilisation of the existing STPs, around 420 km of new sewage lines are being laid in Kanpur. As of October 2019, nearly 190 km of lines have already been laid and the work on this project is likely to be completed by August 2020.
Under Namami Gange, a new STP is also being built in Kanpur’s Pankha. The STP, which will have a treatment capacity of 30 MLD, is coming up under the Hybrid Annuity based Public-Private Partnership model.
Under this model, up to 40 per cent of the capital investment will be made by the government through construction-linked milestones. This would ensure timely completion of projects. The remaining capital will be paid over the life of the project as annuities along with operation and maintenance cost expenses, and will be linked to the performance of the STP. This would ensure continued optimal performance of the infrastructure commissioned under Namami Gange.
Five STPs, which will have a combined treatment capacity of around 319 MLD, are already being constructed under this model in Varanasi, Mathura, Kanpur, Unnao, Farrukhabad and Parayagraj, some of the most polluting cities.
The 14 MLD capacity Sarai STP, India’s first sewage treatment unit built under the Hybrid Annuity Model, was recently inaugurated in Uttarakhand’s Haridwar.