Burgeoning populations coupled with slow and unorganized development in sewage infrastructure pose a major threat to the sanitation conditions of cities, subsequent river water quality and public health of the inhabitants. According to the report on the Composite Water Management Index by the NITI Aayog last year, about 600 million people face high-extreme water stress. To tackle this menace, several cities are taking precautionary measures to strengthen their water and sewage infrastructure. That said, the Orange city of Maharashtra, Nagpur is all set to recycle 90 per cent of its sewage water by increasing the capacity of its treatment plant to with an aim to recycle 480 million liters of the total 525 million liters per day (MLD) is generated in the city. With this, Nagpur will become India’s only city to treat wastewater at this level.
Meanwhile, the state-run National Thermal Power Corporation and Maharashtra State Power Generation Company has agreed to procure 150 MLD and 190 MLD treated water, respectively, making it as a profitable project for the city as it will cover all its expenses. The 'Nagpur Model' is definitely commendable and something that other cities in India can take a cue from.
Bengaluru, which is generating 1,600 MLD sewage, recycles only 600 MLD, meaning that almost 80 per cent is going waste. The untreated water then flows to other water bodies like lakes and rivers, polluting them, which then leads to the bizarre phenomena like catching fire. Bengaluru, which is predicted to be the first Indian city that will run out of water, urgently need to step up its game in recycling and reusing wastewater.
Neighbouring Chennai, which too is facing a similar situation, is in the process of increasing its recycling capabilities. The city generates around 580 MLD of sewage. The Tamil Nadu Government recently allocated Rs 86 crore to rejuvenate the city's water bodies using treated sewage water. According to the plan, which is based on IIT-Madras's ‘recycling and reusing’ model, treated sewage water will be pumped into the water bodies, which will then help in increasing the ground water levels.
In Delhi (which generates waste water of over 2,600 MLD) around 1,600 MLD is treated and 338 MLD is reused. Last year, the Delhi Government had also proposed to supply treated sewage water to though Delhi Jal Board's pipelines. According to the proposal, treated sewage water will be pumped to Palla, where it will mix with river water channel. It will then flow downstream 11km to Wazirabad where it will be treated again before it is supplied to individual homes.