NEW DELHI: With the Yamuna still choking from decades of untreated waste, the Delhi Jal Board has unveiled a far-reaching Sewerage Improvement Scheme (SIS) to overhaul the city’s ageing sewage systems and plug pollution pathways into the river, officials said on Monday.
The SIS is a master plan that blends traditional engineering with new technologies. The board plans to deploy artificial intelligence and drone surveys to map unsewered pockets, drains and outfalls.
DJB has issued a tender to hire qualified consultants who will prepare a comprehensive programme to strengthen, optimise and expand sewerage infrastructure with a planning horizon to 2043.
The consultants have 15 months to deliver a full report. Officials said the study will consolidate data from five earlier reports on sewerage gaps and Yamuna pollution, and will include a thorough needs assessment factoring in demographic growth and future urban development.
The plan will set out short-term rehabilitation measures, longer-term upgrades and the capital required to build new treatment plants and upgrade existing sewage treatment plants (STPs).
At present, Delhi’s installed treatment capacity across 37 STPs stands at about 600 million gallons per day (MGD), while estimated sewage generation is roughly 792 MGD.
Eighteen STPs are currently undergoing upgradation. The SIS study will analyse operational performance, network coverage, pumping stations and system bottlenecks to prioritise interventions that can quickly reduce untreated discharges.
A central objective is to eliminate any untreated sewage reaching the Yamuna, whether discharged directly or via stormwater and drainage networks. To achieve this, consultants will carry out drone reconnaissance of major drains and the hundreds of sub-drains that feed them, and identify unsewered settlements that must be connected to the sewer network.
DJB noted that the Yamuna traverses 52 km within Delhi, and a critical 2 km stretch between Wazirabad and Okhla is especially contaminated. Authorities have also flagged 22 large drains, including the Najafgarh and Shahdara drains, as major pollution sources.