From Idols to Compost: Tracing Ganesh Chaturthi Waste in Mumbai

When the last drumbeat fades and the crowds drift back home, Mumbai is left with more than just memories of chanting and sweets. The city’s streets, ponds and beaches are suddenly littered with plaster‑of‑Paris idols, wilted garlands, fruit peels and mountains of prasad. What happens to all that after the Ganesh Visarjan?

First, the idols. In 2025 alone, nearly two hundred thousand Ganesh statues sank into water across the metropolis – from modest household figures to towering public pandals. The Brihanmumbai Municipal Corporation (BMC) has been expanding its ‘retrieval’ network: 281 artificial immersion ponds, 44 beaches, 23 natural lakes – a total of 348 designated spots. Within 24 hours of immersion, specially‑equipped crews dive in, haul the plaster‑of‑Paris (PoP) statues out and load them onto trucks. The plan isn’t just to dump them; the recovered PoP is sent to processing units where it may be reborn as new idols, plasterboards, bricks, or even medical plaster.

Then there are the garlands, flowers and other offerings – collectively called nirmalya. In the same year the BMC gathered about 508 metric tonnes of this floral waste from collection points set up at each immersion site. Instead of letting it rot in the water, they whisk it away to composting facilities. The resulting compost is later spread across Mumbai’s public gardens, turning a fragrant tribute into soil nourishment.

Perhaps the most surprising twist is the fate of the food and prasad. At the bustling Lalbaugcha Raja mandap, the BMC rolled out the ‘Prasad to Power’ scheme. Roughly 8‑10 metric tonnes of wet organic waste are collected daily, then ferried to biomethanation plants attached to hospitals in Nair, Kasturba, GTB and Sion. Over ten days, the process is expected to churn out about 7,700 units of renewable electricity, feeding patient wards and corridors. It’s a modest but clever way of turning leftovers into light.

All of these streams – idols, flowers, food – are kept separate right at the source, thanks to clearly marked bins and volunteers who guide devotees. The BMC’s waste‑segregation blueprint, though still a work in progress, has cut down the amount of rubbish that actually ends up in the sea.

So, the next time you hear the final chanting and see the idol submerge, remember there’s a whole backstage crew hustling to recycle, compost and generate power. It’s a reminder that a centuries‑old tradition can still evolve, one reclaimed statue and one bag of compost at a time.