Legacy Waste management in India
The Municipal Administration and Urban Development (MAUD) has approved the model request for proposal (RFP) to be floated by all urban local bodies (ULBs) for legacy waste management through appropriate methods like bio-mining and bio-remediation in municipal solid waste (MSW) landfills.
Municipal solid waste in India
According to a 2016 estimate, annually India produces 277 million tonnes of municipal solid waste. This amount is equal to 13% of the global waste. At present, India only has 1604 solid waste treatment plants to treat this waste. They too, are not operating at their maximum capacity. So on an average, India recycles only 20-25% of the waste generated. The remaining waste remains untreated.
India needs to reclaim or recycle or permanently close more than 3,000 dumpsites. It is because of various issues such as unscientific construction, attained maximum capacity, etc. The legacy wastes dumped for a long time create irreversible damage to the environment by leachate, emitting greenhouse gases, pollutes groundwater, etc.
Legacy waste
Legacy wastes are the wastes that have been collected and kept for years at some barren land or a place dedicated for Landfill (an area to dump solid waste). Legacy wastes not only occupy large space, but also become a breeding ground for pathogens, flies, malodours and generation of leachate, which may lead to water contamination. They also contribute to generation of greenhouse gases and pose risk of uncontrollable fire.Legacy waste can be grouped into four categories:
- Contained and stored wastes (wastes stored in tanks, canisters, and stainless steel bins etc will come under this category)
- Buried waste
- Contaminated soil and groundwater
- Contaminated building materials and structures waste.
Composition of Legacy Waste
The major components of legacy waste are-
- Fine soil/sand-like material are the decomposed and mineralized organic wastes mixed with silt, sand, and fine fragments of construction and demolition (C&D) wastes. This is the major fraction in the majority of landfills.
- Scrap polymeric and combustible materials include plastics, paper, cardboard and textiles etc.
- Stones which are greater than 20 millimetres in size.
- Miscellaneous items include broken glass, sanitary waste and diapers, metallic fractions such as razors, needles, etc.
Challenges in managing legacy waste
- The presence of heavy metals poses challenges in managing legacy waste. The finer sand materials consist of chemicals such as cadmium, nickel, mercury, and organic pollutants also.
- There is not enough data available on legacy waste in India. Even if the government wants to reclaim the land by processing the legacy waste, there is no data available with the government on the quantum of legacy wastes in all the landfills.
- One policy is not feasible: The legacy waste components depend upon the age of the landfill. In India waste is dumped in various landfills at various times. This makes the character of legacy waste differ from one landfill to another and even within the landfill itself.
- India do not have enough capacity to process these landfills. At present, India only has 1604 solid waste treatment plants. These plants are not enough to treat the present landfills.
- Unable to follow the CPCB guidelines. The Central Pollution Control Board recommended ‘bioremediation’ to treat the legacy waste and reclaim the old landfills. But bioremediation is only possible for dumpsites having a higher organic content. Since the waste segregation is not done at the source treating wastes with bio-remediation is not feasible.
