Growing challenge of legacy waste
Clearing Legacy Waste Through Biomining: Indian cities are facing a serious challenge from accumulated legacy waste, which refers to untreated solid waste dumped over several decades. These dumpsites occupy valuable urban land and pose major environmental and health risks. Addressing this issue has become a priority under modern solid waste management reforms.
In this context, the initiative by the Greater Chennai Corporation marks a significant step in urban environmental governance.
Progress in Chennai waste clearance
The Greater Chennai Corporation has successfully cleared nearly 50 lakh metric tonnes of legacy waste out of an estimated 90 lakh metric tonnes. This clearance has been achieved using the biomining process, which enables scientific remediation without expanding landfill areas.
The remaining waste is targeted to be completely removed by February 2027, aligning with long-term sustainability goals. This phased approach reflects the technical and logistical complexity involved in handling decades-old waste.
Static GK fact: Municipal solid waste in Indian cities typically consists of biodegradable waste, recyclables, and inert materials, with legacy dumps having a high proportion of mixed and degraded waste.
Role of the Perungudi dumpyard
The biomining operation is being carried out at the Perungudi dumpyard, one of the largest legacy waste sites in Chennai. Over the years, this site had grown into a major environmental concern due to leachate formation and methane emissions.
By applying biomining, the dumpyard is gradually being reclaimed. Recovered land can later be reused for public or ecological purposes, improving urban land efficiency.
Static GK Tip: Dumpyards located near coastal cities pose additional risks due to groundwater contamination and saline intrusion.
Technology behind biomining
The biomining technology used at Perungudi is provided by Blue Planet Environmental Solutions. This method involves the scientific segregation and treatment of waste rather than simple dumping.
Biomining is a technique that uses micro-organisms such as bacteria, archaea, fungi, or plants to process solid waste. While traditionally associated with metal extraction from ores, in waste management it helps in stabilizing waste and recovering usable materials.
Recyclables are separated, inert material is reused for construction, and organic matter is biologically treated. This significantly reduces landfill volume and environmental damage.
Environmental and policy significance
Clearing legacy waste reduces greenhouse gas emissions, prevents soil and water pollution, and improves public health conditions. It also supports India’s broader goals of urban sustainability and the circular economy, where waste is treated as a resource.
The Chennai model demonstrates how technology-driven interventions can resolve long-standing urban problems. It also sets a precedent for other metropolitan corporations dealing with similar legacy waste challenges.
Static GK fact: Biomining is preferred over incineration as it avoids air pollution and high energy consumption.
Static Usthadian Current Affairs Table
Clearing Legacy Waste Through Biomining:
| Topic | Detail |
| City authority | Greater Chennai Corporation |
| Total legacy waste estimated | 90 lakh metric tonnes |
| Waste cleared | Nearly 50 lakh metric tonnes |
| Target completion | February 2027 |
| Key dumpyard | Perungudi dumpyard |
| Technology used | Biomining |
| Technology provider | Blue Planet Environmental Solutions |
| Environmental benefit | Reduced landfill volume and pollution |
| Policy relevance | Urban sustainability and waste remediation |
