Any person who visits Delhi for the first time in their life will be amazed by the presence of three ‘hills’ at prominent and noticeable locations in Delhi. Yes, ‘hills’, you read it right, in a city that is right in the middle of the Indo-Gangetic plains.
But there are a few factors that differentiate these three hills from ones that we find in India’s picturesque hill stations. First, while the other hills are made of rock, Delhi’s are made of rotting waste. Second, while fresh air and the chirping of birds accompany other hills, Delhi’s are characterised by a putrid smell and the decaying carcasses of animals. Third, and, perhaps, the most crucial difference is that while most hills are made from natural orogenic processes, the ones in Delhi are man-made – they are ‘landfills’.
The 3 Landfill Sites in Delhi are Far Beyond Their Capacity Now
As many as 20 landfill sites have been developed in Delhi since 1975, out of which 15 have already been closed down and two have been suspended. At present, there are three landfill sites in operation: Ghazipur, Bhalswa, and Okhla.
These three sites receive solid waste from all zones of the Municipal Corporation of Delhi (MCD). Even though the three landfill sites have exhausted their capacity years ago, waste-dumping still continues.
There are various negative externalities related to these landfill sites:
Contamination of groundwater from leachate emissions
Contamination of surface water resources from leachate emissions. For example, the presence of channels directing the flow of surface water runoff from Ghazipur landfill to Hindon canal, and thereby into the Yamuna River (6.2 km east of landfill).
Burning of landfill gas (LFG) due to anaerobic decomposition of biodegradable waste (Delhi’s landfills have 55% to 60% of biodegradable/organic material).
Dust generated from waste and on-site vehicular movement due to the high concentration of construction and demolition waste (C&D).
Loss of visual amenity due to the height of the landfills, as most of these are located on national highways.
Risk of waste landslide
Workers at these landfill sites are not given personal protective equipment such as masks, gloves, and shoes, thereby imposing an occupational health risk.
Delhi’s landfill sites, apart from being an eyesore and a health hazard, have now also become a serious safety issue. A massive fire broke out at the Ghazipur landfill site on 20 April, Wednesday, with a huge cloud of smoke enveloping the region. This was the third such fire since 28 March. The recurrent fires had recently prompted the Delhi High Court to step in and ask the Centre, the Delhi government, the Delhi Pollution Control Commission, and other authorities concerned for a status report.
After the fire on Wednesday, Delhi Environment Minister, Gopal Rai, directed MCD officials and a special committee to visit Mumbai and study the technology used there to remove the gas emitted from landfill sites, which is a major cause of landfill fires.
Naturally, apart from this, there ought to be other, systemic measures that need to be undertaken.
Retire Old Landfill Sites
Landfills that are past their expiration date should be retired, ie, wast-dumping there should be stopped and land should be reclaimed. Either new waste-processing facilities can be set up on the reclaimed land or it can be covered with soil to create green areas, as was done with the Indraprastha Park (between Ring Road and Humayun’s Tomb), which was a landfill site for 20 years.
But how do we reduce the amount of waste in landfills? A joint project between the National Highways Authority of India (NHAI) and the MCD for the reclamation of the Ghazipur landfill offers clues.
Through this project, up to 75% of the waste dumped at the Ghazipur landfill would be used for road filling (expansion of the six-lane NH-24 to 14 lanes) and the residue would be deposited safely at a new, engineered landfill site.
However, a feasibility study conducted by the Central Road Research Institute (CRRI) found that the solid waste at Ghazipur was of heterogeneous material, which is patently ill-suited for road construction. It had large-sized plastics, clothes and even boulder-sized C&D waste.
The solution to this was scientific segregation of waste and selecting waste of different ages. The final solid waste selected for road construction was a non-plastic, non-swelling, coarse-grained material.
This model should be replicated across other landfill sites.
Paving Access Roads to Cure the Problem of Dust
First, to cure the problem of leachate, a leachate inceptor drain should be installed at the toe of the waste slope around the entire landfill. The leachate drain pipe should have its highest level at the entrance area to the landfill with a collection point in the lowest location at the site.
Second, the solution to cure the problem of dust is two-fold. ‘Paving’ the access roads will bring down dust emissions from on-site vehicular movements. The unpaved roads at the landfill should be watered (with raw water/leachate) frequently to mitigate dust. Additionally, instead of dumping C&D waste in landfills, it should be transported to and processed at specialised C&D waste plants, which convert the waste into bricks, paving blocks, kerbstones, manufactured sand, etc. These can then be purchased by the government to use in public works.
Third, it is important to prevent a build-up of gas within the landfill. Landfill gas (LFG) consists of methane (CH4), carbon dioxide (CO2) and a large number of other components in smaller amounts. A plant should be set up whereby,
LFG is collected and converted into electricity, which, in turn, should be purchased by the government, and
Unusable LFG should be flared on a daily basis to reduce greenhouse gas emissions.
How to Reduce the Amount of Waste Dumped at Landfills?
As per the Delhi Pollution Control Committee (DPCC), around 51% of Delhi’s waste is dumped, without segregation or treatment, at landfill sites. To prevent this, the following end-to-end mechanism should be adopted:
Mechanized auto-tippers collect waste from every household in the designated zone.
Instead of dumping this waste at dhalaos (waste receptacles), the tippers empty this waste into trucks of capacity ~1000-2000 MT.
These trucks then take the solid waste to a transfer station
At the transfer station, the waste is suitably segregated and sent to the landfill.
The segregated bio-degradable waste is then processed through an RDF (Refuse-Derived-Fuel) Plant or a Composting Plant or a Waste-to-Energy Plant, all of which are located within the precincts of the landfill site.
The non-biodegradable waste is disposed of scientifically in the landfill pit.
Delhi’s ‘hills’, aka landfills, are towering monuments to the failures of the municipal authorities and successive state governments. It’s time the authorities found some workable solution to tackle not just recurrent fires, but the problem of ever-growing waste hills.
(The author is an independent columnist. This is an opinion article and the views expressed are the author's own. The Quint neither endorses nor is responsible for them.)