Delhi’s plan to double sewage-treatment capacity is a major expansion of the city’s urban utility system, but the project also exposes a harder problem: treatment plants cannot clean wastewater that never reaches them. The Delhi Jal Board has approved a ₹7,373-crore programme involving 35 decentralised sewage treatment plants and 13 new sewage treatment plants, with the stated objective of stopping untreated wastewater from entering the Yamuna.
The programme is expected to be implemented over the next two and a half years with financial assistance from the National Mission for Clean Ganga. The proposed plants will together add 328 million gallons per day of treatment capacity. Delhi currently has 37 sewage treatment plants with a combined capacity of about 814 MGD, broadly matching the city’s reported daily sewage generation.
That comparison suggests that Delhi’s problem is not simply a shortage of installed treatment capacity. The report identifies two other constraints: several areas do not have adequate sewer networks, and some existing treatment plants are not operating according to prescribed standards. In practical terms, the city can have nominal capacity on paper while untreated sewage continues to flow into drains and the river if neighbourhoods are not connected to the sewer system or if plants do not perform consistently.
The new plan therefore combines capacity creation with the upgrading of existing facilities. The Delhi Jal Board has completed upgrades at 28 sewage treatment plants, while work at the remaining nine is expected to be completed by December next year, according to the report. These upgrades are expected to add about 56 MGD of capacity by December 2027.
The expansion is also designed to distribute treatment closer to areas where wastewater is generated. The 35 decentralised plants are expected to increase capacity by approximately 170 MGD. Unlike a system that relies only on large centralised plants, decentralised treatment can reduce the distance wastewater has to travel before treatment. However, the supplied information does not establish how each plant will be connected to local sewer networks, how treated water will be reused, or what operating arrangements will govern the facilities after construction.
The 13 planned sewage treatment plants will be located at Jagriti, Kondli, Rohini, Pappankalan, Rithala, Keshopur, Coronation Pillar, the ISP Burari campus, Nilothi, Kailash Nagar, Shastri Park, the RME-180 drain interception site and Delhi Gate. Their locations indicate that the project is not limited to one riverfront intervention. It covers treatment facilities and drain-interception points across different parts of Delhi, reflecting the geographical spread of the city’s sewage challenge.
The Delhi Jal Board’s stated target is to raise Delhi’s total sewage-treatment capacity to 1,500 MGD by 2028. Reaching that number would require the new plants, decentralised facilities and upgrades to be completed on schedule. It would also require the additional capacity to be operational rather than merely constructed. The report provides the planned capacity and implementation milestones, but does not provide plant-wise operating data, current utilisation rates or performance results for facilities that have already been upgraded.
This distinction matters because sewage treatment is a chain rather than a single piece of infrastructure. Wastewater must be collected from homes and establishments, conveyed through functioning sewer lines, intercepted before it reaches open drains, treated to the required standard and then discharged or reused safely. A breakdown at any stage can reduce the environmental benefit of investment in the treatment plant itself.
The project’s institutional structure also shows why the outcome will depend on coordination. The Delhi Jal Board has approved the programme and is preparing to issue tenders, while the National Mission for Clean Ganga is expected to provide financial support. The implementation will therefore involve planning, funding, procurement, construction, commissioning and operations. The supplied report does not specify the financing split, tender schedule, contracting model or the responsibility for long-term operations and maintenance.
For Delhi residents, the most visible concern is the condition of the Yamuna, but the underlying issue is citywide utility coverage. Areas without sewer networks cannot benefit from additional treatment capacity unless collection infrastructure is built alongside the plants. Similarly, upgrading a treatment plant improves results only if the plant receives the intended volume of sewage and continues to meet the prescribed standards. The report presents both network absence and plant performance as continuing contributors to river pollution.
The numbers reveal the scale of the proposed intervention. The existing system has approximately 814 MGD of capacity, while the planned citywide target is 1,500 MGD by 2028. The new facilities are expected to contribute 328 MGD, and upgrades to older plants are expected to add another 56 MGD by December 2027. These figures point to a substantial increase, but they are not equivalent to the quantity of sewage actually treated to compliant standards. Capacity, utilisation and compliance will need to be assessed separately.
The project also illustrates the limits of measuring environmental infrastructure through construction alone. New plants can be counted, capacity can be announced and tenders can be issued, but the effect on the Yamuna will depend on whether wastewater is intercepted and conveyed reliably. The present report confirms the planned expansion and the Board’s approved actions; it does not yet establish the expected reduction in untreated discharges or provide evidence of improved river-water quality.
The next stage is therefore administrative as much as engineering-led. The Delhi Jal Board is expected to begin the tendering process for the approved works. The remaining upgrades are scheduled for completion by December 2027, while the broader target is to raise total sewage-treatment capacity to 1,500 MGD by 2028. Those milestones, along with plant-level performance and sewer-network coverage, will determine whether Delhi’s capacity expansion becomes a functioning river-clean-up system rather than only a larger treatment-infrastructure inventory.
