NEW DELHI: The Delhi Jal Board plans to expand the use of reused water by developing dedicated supply networks around its 37 existing sewage treatment plants (STPs), seeking to reduce the city’s dependence on freshwater for non-potable requirements, a senior official aware of the development said.
As an immediate step, around 12 major reuse-water network projects are already under execution across several parts of Delhi and are expected to be operationalised after the monsoon season.
The projects will form part of the board’s larger plan to create a distribution system for reused water across the national capital, supplying reclaimed water to water bodies, farms, horticultural areas and other bulk users.
The 12-project action plan identifies 114.5 million gallons per day (MGD) of additional reuse potential, with several works already underway and others proposed.
The move is significant as the DJB has a substantial volume of treated water that can be put to productive use. According to DJB data accessed by the newspaper, around 487 MGD of treated water is currently available for reuse, while only about 120 MGD is being reused, leaving an estimated 367 MGD of untapped potential.
Among the ongoing projects are schemes to supply 15 MGD to lakes in Rohini Sector 25, 15 MGD to Iradat Nagar from Rithala, 10 MGD to Nilothi Lake, 5.5 MGD to Tikri Khurd Lake, 5 MGD to lakes at Pappankalan, Najafgarh and Dwarka WTP, and 5 MGD to the lake at Shahdara Link Drain from Chilla STP.
Other works include supplying reused water to Aya Nagar Forest, Dera Mandi and Jaunapur farmhouses from Ghitorni STP; Pushpanjali farmhouses from Kapashera; Bakoli and Baktawarpur farmhouses from Narela; NTPC Eco-Park from Okhla; and farmhouses in Chhatarpur from Mehrauli STP.
As part of its long-term strategy, the board plans to map demand around each of the 37 STPs to identify where the unused reuse potential can be absorbed. The exercise will identify bulk consumers and assess their requirements before new distribution networks are planned. “Where a reuse-water network already exists, it will be augmented, while areas without one will get new networks,” the official said.
Potential users will include horticulture, water bodies, washing and other bulk requirements. “The idea is to match the availability of reused water at individual STPs with demand in nearby areas and then develop networks where there is sufficient requirement,” he added.
The board will first assess the availability of reused water at each STP and identify potential consumers and their demand. The economic viability of laying networks will also be examined before individual projects are taken up.
Water for reuse
DJB plans to map demand around all 37 STPs, identify bulk consumers and assess their requirements before laying new reuse-water networks
Initiative could reduce the use of freshwater for purposes that do not require potable-quality water and lessen dependence on groundwater, particularly for horticulture & irrigation
Currently, about 92 MGD is being utilised, while another 25-30 MGD is supplied in bulk to the NDMC, taking total utilisation to around 120 MGD
Using reused water for water bodies could also aid groundwater recharge through percolation
Several projects to recycle water underway across city
Among the ongoing projects are schemes to supply 15 MGD to lakes in Rohini Sector 25, 15 MGD to Iradat Nagar from Rithala, 10 MGD to Nilothi Lake, 5.5 MGD to Tikri Khurd Lake, 5 MGD to lakes at Pappankalan, Najafgarh and Dwarka WTP, and 5 MGD to the lake at Shahdara Link Drain from Chilla STP. Other works include supplying reused water to Aya Nagar Forest, Dera Mandi and Jaunapur farmhouses from Ghitorni STP; Pushpanjali farmhouses from Kapashera; Bakoli and Baktawarpur farmhouses from Narela; NTPC Eco-Park from Okhla; and farmhouses in Chhatarpur from Mehrauli STP.
