After decades of environmental stress and public health concerns, one of Bengaluru’s most contested waste landscapes is showing signs of transformation. Civic authorities have advanced to the second phase of biomining at the Mandur dump site in east Bengaluru, with a substantial portion of long-buried waste now scientifically processed and diverted into reusable material streams.
Mandur has long symbolised the costs of unplanned urban expansion, accumulating an estimated 22 lakh tonnes of mixed waste over years when segregation and processing systems were either absent or poorly enforced. The current clean-up programme adopts a resource recovery approach rather than conventional excavation, aiming to minimise landfill dependence while reducing long-term ecological risks. Phase two of the operation focuses on processing over 10 lakh tonnes of legacy waste. Officials overseeing the programme indicate that more than 90% of this volume has already been treated using mechanical screening and biological stabilisation methods. The process separates waste into multiple fractions, allowing recoverable materials to be channelled back into productive use while shrinking the volume that requires final disposal.
The largest recovered fraction is stabilised organic matter, commonly referred to as bio-earth. This material accounts for nearly two-thirds of the processed waste and is being repurposed as a soil conditioner, including for agricultural use in nearby districts. Waste management experts note that while bio-earth cannot replace fertilisers outright, it helps improve soil structure and moisture retention, offering secondary environmental benefits.
Energy recovery also forms a key component of the operation. A significant share of the processed waste has been converted into refuse-derived fuel, which is being supplied to authorised waste-to-energy facilities. This diversion reduces methane emissions that would otherwise arise from decomposing waste while contributing marginally to the city’s renewable energy mix. Other recovered materials include inert debris, recyclables such as plastics and metals, and construction waste, all routed through approved recycling or disposal channels. Urban planners point out that such granular segregation is essential to ensuring biomining does not simply relocate pollution from land to other systems.
From a climate resilience perspective, the implications extend beyond waste volumes. Legacy dumps are major sources of groundwater contamination, landfill fires, and uncontrolled greenhouse gas emissions. Reducing the waste mound lowers these risks while freeing up land that can potentially be reclaimed for non-polluting civic uses, subject to environmental safeguards. Residents around Mandur have long raised concerns over air quality, water safety, and declining land values. While biomining does not immediately erase these impacts, environmental analysts say sustained progress could gradually stabilise the local ecosystem and restore trust in municipal waste governance.
As Bengaluru continues to grow, the Mandur project is increasingly viewed as a test case for how Indian cities confront historical environmental liabilities. The success of subsequent phases will depend not only on processing efficiency but also on whether parallel reforms prevent new waste legacies from forming elsewhere.
