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Introduction

Legacy waste refers to accumulated waste disposed of in landfills or dumpsites over many years or decades.

  • It includes municipal solid waste, industrial waste, construction and demolition debris, etc.
  • Legacy waste causes groundwater contamination, air pollution, and greenhouse gas emissions.

Methods to Mitigate Legacy Waste

1. Landfill Mining and Reclamation (LFMR)

  • Involves excavating old waste to recover materials and remediate land.
  • Example: Ghazipur landfill, Delhi.
  • Benefits:
    • Recovers metals, plastics, glass
    • Reduces landfill volume
    • Remediates land for reuse
  • Challenges:
    • High cost, technical complexity
    • Risk of hazardous release during excavation

2. Bioremediation and Bio-mining

  • Uses microbes or plants to break down contaminants.
  • Example: Kodungaiyur landfill, Chennai (microbial degradation and metal recovery).
  • Benefits:
    • Eco-friendly
    • Reduces toxicity
  • Challenges:
    • Time-consuming
    • Depends on environmental conditions

3. Waste-to-Energy (WtE)

  • Converts non-recyclable waste into heat, electricity, or fuel.
  • Example: Okhla WtE Plant, Delhi.
  • Benefits:
    • Reduces waste volume
    • Generates renewable energy
  • Challenges:
    • High capital cost
    • Emission concerns

4. Mechanical Biological Treatment (MBT)

  • Combines mechanical sorting with biological stabilization.
  • Example: MBT facility in Pune.
  • Benefits:
    • Recovers recyclables
    • Stabilizes organic waste
  • Challenges:
    • High infrastructure cost
    • Dependent on waste type

5. Phytoremediation

  • Plants absorb and remove contaminants from soil and water.
  • Example: Sunflower and mustard plants used at old dumpsites.
  • Benefits:
    • Low-cost and green method
    • Aesthetic improvement
  • Challenges:
    • Slow process
    • Limited to certain pollutants

Conclusion

An integrated strategy combining multiple mitigation methods, tailored to site-specific conditions, can effectively reduce the environmental and health impacts of legacy waste. Such efforts not only manage existing waste but also promote sustainable long-term waste practices.

Legacy Editor Changed status to publish November 26, 2025