If the current trend of dumping fresh waste continues, Delhi will have to deal with an additional 1 crore tonnes of waste in another 5 years, along with the existing 2.8 crore tonnes
The result of Swachh Sarvekshan (SS) 2022 has not been surprising for the residents of Delhi, who have been subjected to harsh environmental conditions over the past many years.
None of the three erstwhile corporations in Delhi — east, south and north Delhi — were considered for Swachh Sarvekshan’s “garbage-free city” category.
There has been a marginal improvement in the ranking of the city’s performance in the SS 2022. But still, tremendous efforts are needed to establish a sustainable solid waste management system and achieve a credible ranking in SS.
It’s high time for Delhi to take decisive actions to save the city from the existing ‘waste crisis’. The flagship Swachh Bharat Mission (SBM) 2.0 is instrumental in establishing sustainable solid waste management in cities across the country.
The mission envisages “garbage-free cities” — where the cities are mandated to remediate their legacy waste dumpsites. It also advocates enhancing waste treatment and recycling efficiency — by at least 80 per cent of the existing and projected waste generations.
Currently, about 50 per cent to 60 per cent of the total waste generated in Delhi is disposed of in three dumpsites without any treatment.
The status of municipal waste generation in the three erstwhile corporations — now merged with the Municipal Corporation of Delhi — is given below:
|Waste generation (TPD)||3600||4500||2600|
|Processing and Disposal (TPD)||1600 (WtE plant)
300 TPD (local composting units)
|2300 (WtE plant)||900 (WtE plant)|
|Waste going to the dumpsites||1700||2200||1700|
Source: Swachh Bharat Mission - Urban
The city relies heavily on three waste-to-energy plants in the name of waste treatment, adding more stress to its compromised air quality. Nearly 50 per cent of the waste generated in the city is disposed of in the three dumpsites.
What to do with the legacy waste?
The humongous quantum of legacy waste in Delhi’s three dumpsites is an offshoot of solid waste’s mismanagement for over a couple of decades. These garbage mounds have occupied more than 200 acres of Delhi’s urban land.
These sites can be reclaimed if the mandate of the flagship SBM 2.0 is translated into actions. This would bring significant environmental and health benefits in addition to economic gains.
Delhi has a clear mandate to reclaim the three dumpsites by March 31, 2024 — by remediating 2.8 crore metric tonnes of legacy waste, according to SBM 2.0 operational guidelines. The estimated cost of remediation is around Rs 2240 crore.
However, treating and disposing of 2.8 crore tonnes of legacy waste is much easier said than done. It requires systematic planning coupled with a roadmap for utilising mined fractions for gainful application, which comes with its own challenges.
The composition of legacy wastes from different dumpsites in Delhi shows a significant proportion of fine-soil-like material — 40 to 70 per cent.
Combustible material ranges from 15 to 18 per cent by weight. Coarser particles, such as broken bricks, masonry, stones, etc, constitute nearly 10-15 per cent of the total waste.
Other miscellaneous fractions — broken glass and metallic fractions such as razors, needles, sanitary waste and diapers — constitute around 1-4 per cent of the total waste.
These four significant fractions of waste influence the choice of treatment technology and end-use of recovered material. As mandated by the government, the city is bioremediating the three dumpsites, including Ghazipur, Okhla and Bhalswa.
The following is a summary of the progress:
|Particulars||South (Four zones)||North (Six zones)||East (Two zones)|
|Area of dumpsite||62 Acre||70 Acres||70 Acres|
|Age (years of operation)||26||28||38|
|Height||45 meters||62 meters||65 meters|
|Legacy waste||60 Lakh MT||80 Lakh MT||140 Lakh MT|
|No. of trommels installed for biomining of legacy waste||14||18||12|
|Total processing capacity of Trommels||7000 TPD||10000 TPD||5000 TPD|
|Inert /C&D Disposal||Inert at National Highways Authority of India (NHAI) sites andlow lying areas C&D waste/ inert utilized as cover material at Okhla for covering of fresh MSW and in construction of slopes/ platforms/ internal Kachha roads.||NHAI sites Low lying areas C&D waste at processing plants.||A. Inert is disposed ofat Eco Park, NTPC, NHAI site. C&D is utilized for repair of internal road and covering or tipping area SLF Ghazipur.|
Source: Swachh Bharat Mission - Urban
The cumulative installed capacity of the trommels — equipment used for segregation — at Delhi’s dumpsites is reportedly 22,000 tonnes per day. This suggests that the city can get rid of its legacy waste in another five-six years if these trommels are used exclusively for screening legacy wastes.
However, it is essential to note that the city should also be ready to deal with the enormous quantities of — excavated mass of inert material, scrap combustibles, construction and demolition waste and fine-soil-like materials.
The authorities should formulate plans for using the mined fractions.
Besides, it is crucial to ensure proper stabilisation as it helps in reducing the moisture and volume of the legacy waste. The process of biodegradation can be fastened by spraying bio-inoculum on legacy waste.
Currently, the city’s capacity to deal with biomining and using the excavated fractions for gainful application is limited. It is important to ensure that no fresh waste is added to the dumpsites.
It is practically impossible to remediate the legacy waste if the city keeps adding new waste daily.
For example, suppose the current trend of dumping fresh waste continues. In that case, Delhi will have to deal with an additional one crore tonnes of waste in another five years, including the existing 2.8 crore tonnes of legacy waste.
The mandate under SBM 2.0 looks very promising. But a proper roadmap to divert fresh waste from reaching landfill would be highly critical to the success of the whole endeavour.
The Government of India should ensure substantial financial devolution for improving the solid waste management ecosystem.
It is equally important to start planning the augmentation of recovery and treatment efficiency based on the current and forecasted municipal solid waste generation.
This is feasible only if different waste components, such as biodegradable and non-biodegradable garbage, are segregated at the source.
There are some classic models in India which can be adopted by aligning them to the regional needs. The city needs to ensure that the biodegradable fraction of waste —nearly 5,500 tonnes per day — is treated scientifically.
Converting organic waste into bio-compressed natural gas (CNG) could also be a game-changer. Bio-CNG can be utilised to fulfil the city’s demand — including vehicle fuel or bulk industrial consumption.
Similarly, the dry waste can be managed and channelised to the recycling facilities with the help of nearly 80,000 informal waste pickers currently working in the city.
It is important to notice that the efficiency of any treatment technology depends on the quality of feedstock (segregated waste fractions). Clearly, source segregation is non-negotiable if the city wants to ensure efficient processing and treatment of waste.
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