16-05-2025
Why BMC's 3-year plan to clear Deonar landfill is easier said than done
The Brihanmumbai Municipal Corporation (BMC) on May 14 (Wednesday) floated a Rs 2,368-crore tender to clean up 271 acres (110 hectares) of the larger 311 acres of the Deonar dumping ground by a process of bioremediation within three years.
This comes seven months after the Maharashtra government allocated 124 acres of the landfill to build housing for several thousand residents of the Dharavi slums who will be relocated as part of the Dharavi Redevelopment Project (DRP).
What is the Deonar dumpsite, what is bioremediation, and what challenges could the cleaning plans pose?
The dumping ground
The Deonar dumping ground at Mankhurd-Shivaji Nagar in Mumbai's eastern suburbs is the oldest waste dump in the country. It has been operational since 1927, a time when this area had very little human habitation.
The city and its population have grown enormously since then. Over the past 25-odd years especially, a very large number of people from the economically weaker sections have started to live in Deonar, Mankhurd, and Shivaji Nagar, close to the landfill.
Today, the larger part of the Deonar area is dotted with informal housing units. In their midst stands a mountain of solid waste and garbage rising 40 metres into the sky, the height of a 15-storey building.
The entire area is an enormous health hazard. The M/E ward, where Deonar is located, has the lowest life expectancy among the 25 municipal wards in Mumbai — less than 40 years, almost half the national average. BMC data show this ward accounts for almost 15% of tuberculosis cases in the city.
According to a report by the Central Pollution Control Board (CPCB), the landfill is one of the top 22 methane hotspots in India, from where around 6,200 kg of the colourless, odourless, highly inflammable greenhouse gas is released every hour.
On April 11, The Indian Express published a report detailing how the relocation of slum dwellers under the DRP, which is being steered by the Adani Group and the state's Slum Rehabilitation Authority (SRA), violates fundamental environmental norms.
Before allocating a portion of the dump to build housing, the state government did not consult the Maharashtra Pollution Control Board (MPCB), which is the consenting authority for establishments inside landfills.
'The pollution board was not consulted before sanctioning the land parcel for the said project,' MPCB Member Secretary Avinash Dhakane had told The Indian Express. However, since MPCB is not an 'advisory body', it does not have 'the mandate to raise a dispute against any government institute if they don't consult with us', Dhakane had said.
Under CPCB rules, residential areas should be separated from waste-to-energy (WTE) plants by at least 500 metres, and there should be a no-development buffer zone of 100 metres from the boundary of a landfill.
Bioremediation, which was mandated by the central government in its solid waste management (SWM) guidelines published in 2016, involves treating garbage with microorganisms that flourish in air and sunlight.
After the biodegradable components decompose naturally, non-biodegradable components are either recycled or treated artificially. Rock ore or mine waste are also extracted during this process.
At Deonar, the BMC will begin with a mechanised excavation of the mountain of waste, after which its components will be segregated in a makeshift processing facility at the site. The biodegradable waste will then be allowed to decompose, while the non-biodegradable waste will be disposed of through recycling or at waste treatment centres.
A contractor will be decided by June 12, and work will start immediately, officials of the civic body said.
Of the about 1.85 crore metric tonnes (MT) of waste at the dump, 48% is mainly construction debris, 41% is inert or plastic waste, and 10% is dry/ miscellaneous waste, according to BMC data. Plastic waste and construction debris take a very long time to decompose.
The task that BMC has identified for itself is gigantic. Consider:
* To clean up just the legacy waste that is already there at the dump in three years, BMC will have to process at least 23,000 MT every day. This is almost four times the amount of waste that is generated in Mumbai on a daily basis.
* In 2018, the BMC began clearing 60 acres in Mulund where waste had been dumped since 1968. According to official data, around 47 lakh MT (67%) of the 70 lakh MT of solid waste has been removed so far, and 25 acres (42%) have been reclaimed. The waste at Deonar is almost three times that at Mulund, and the area that the BMC is seeking to reclaim is four times that at Mulund.
* Once the bioremediation process is complete, transporting the residues will need at least 1,200 trucks to be deployed every day, civic officials said. 'There is only one entry and exit point at the Deonar landfill. The landfill is close to Vashi Creek, so we are exploring whether that route can be used to transport the waste,' Kiran Dighavkar, BMC Deputy Municipal Commissioner, SWM, said.
* Mumbai's famous monsoon will be a challenge too. 'Bioremediation cannot take place during the four months of the monsoon every year. That means a loss of 12 months in three years, and a reduction of the window of operation to 24 months,' Dighavkar said.
* Permissions from several departments will be needed before work begins. The site, next to Vashi Creek, is part of the Coastal Regulation Zone (CRZ). There are mangrove patches and nurseries along the creek, over which the environment department has jurisdiction.
'We will need no-objection certificates from the Mangrove Cell, the state forest department, the environment department, and CRZ clearance. If the waste falls in the creek, it will pollute the water,' an official said.
* There is also the cost. Clearing the Mulund landfill has cost Rs 598 crore so far, at a rate of Rs 798 per tonne of waste. Clearing Deonar will likely cost five times more. 'The infrastructure and manpower that will be deployed will be almost four times what was deployed in Mulund,' an official said.
* Civic officials also said that the effectiveness and speed of bioremediation will depend on a range of factors including soil composition, the nature of pollutants, and the weather.
