The plant will treat the wastewater that goes into the Yamuna directly. (Representational)

The Delhi Jal Board (DJB) today approved setting up of a new sewage treatment plant (STP) at Okhla which, it claimed, will be the largest such plant in India.

The plant will be able to treat 124 million gallons of wastewater per day and will come up at a cost of Rs 1,161 crore in three years, the DJB's vice-chairman Dinesh Mohaniya said.

"It will be the largest treatment plant in India and one of the largest in the world," the DJB said in a statement.

The new STP will be set up under the Yamuna Action Plan-III scheme.

The plant will treat the wastewater that goes into the Yamuna directly. It's a major step towards cleaning the river, Mr Mohaniya said.

The STP will remove 41,200 kg organic pollutant load per day and 61,600 kg solid load per day on the Yamuna.

It will cater to around 40 lakh residents of Chandni Chowk, Kashmere Gate, Daryaganj, NDMC areas, Lodhi Colony, Nizamuddin, Okhla, Badarpur, Kalkaji, Malviya Nagar, Katwaria Sarai, Lajpat Nagar, Greater Kailash and South Delhi - from Munirka to Badarpur etc.

The work has been awarded to Suez group's Degremont.

The utility also approved setting up of another 106-MGD water treatment plant (WTP) at Chandrawal, which will help meet the demand for drinking water in the city.

The new WTP, which comes after a gap of 13 years, will be constructed at a cost of Rs 598 crore in three years.

"Delhi did not get any WTP since 2006. The DJB has approved setting up of Chandrawal Phase 2 which can treat 106 million gallons per day (MGD)," Mr Mohaniya said.

"Currently, we are supplying 900 MGD of drinking water. So, the plant will enhance the capacity by more than 11 per cent," he said.

"We have water available for the plant. So, the production will start the day the construction is completed," the DJB VC said.

The peak demand for drinking water in the city is 1,120 MGD.

Currently, we are supplying 900 MGD on an average and the peak production is around 935 MGD, a DJB official said.

Chandrawal Phase 2 will have the advanced technology of ozonisation and activated carbon to ensure uninterrupted working of the plant.

"It will be able to treat high ammonia content up to 4 ppm (parts per million) in the raw water. Earlier, the plant had to be shut down during presence of 1 ppm of ammonia in the raw water, resulting in disruption in water supply in its entire command area," the statement read.

"This will resolve issue of frequent stoppage of WTP due to ammonia discharge by Haryana. This capacity will be constructed in addition to the existing 90 MGD plant," it said.

The board also approved construction of 14 mini STPs in the Najafgarh drainage zone, along with the laying of internal sewerage system in Somesh Vihar, Jhuljhuli and Dichaon Kalan group of colonies consisting of 160 unauthorized colonies and 47 villages with a population of around 8 lakh.

The capacity of the 14 mini STPs will range between 2.5 and 25 million litres per day. The treated water from these plants will be used to recharge 56 water bodies in the area, Mr Mohaniya said.