In a significant step toward integrated waste management and renewable energy, the Brihanmumbai Municipal Corporation (BMC) is in the process of upgrading seven sewage treatment plants (STPs) across Mumbai to generate biogas and supply recycled water.

With a combined treatment capacity of 2,464 million litres (ML) per day, the STPs will rely on solar-powered infrastructure and battery storage to meet 20 percent of their total 16?MW power demand internally. Ashok Mengde, Deputy Chief Engineer (Sewage Project), stated, “Biogas from treated sludge will generate electricity, while the sludge will undergo high-grade (Grade ‘A’) processing.”

Around 30–42 percent of civil work has been completed, and operations will continue through 2025–2026, with equipment installation currently underway. The STPs will implement secondary and tertiary treatment in accordance with Central Pollution Control Board (CPCB) norms. Half of the treated water—about 1,232 ML—will undergo tertiary treatment to produce potable-quality water for reuse. Tanker filling points will be established at each plant, with recycled water offered at nominal rates to reduce fresh water use.