Why reducing size of Delhi’s garbage mountains is easier said than done

From October 2019-2020, the East Delhi Municipal Corporation (EDMC), which handles the landfill at Ghazipur, bio-mined around 3 lakh tonnes of legacy waste out of the 140 lakh tonnes. By October 2021, it had processed 7.81 lakh tonnes, which means around 4.81 lakh tonnes was processed in the second year since biomining began. If an average of around 4 lakh tonnes is processed per year, the remaining 133 lakh tonnes of waste could take another 33 years to process.

All three landfills receive fresh waste daily. In 2021, fresh waste dumped at Ghazipur was more than the legacy waste processed that year.

The deadlines to remediate the landfills are, however, not a few decades away. Ghazipur is to achieve 100% remediation by December 2024, Bhalswa by December 2023, and Okhla by March 2023, going by action plans that the MCDs submitted to the NGT.

The fire at Bhalswa was the fourth instance of a landfill fire in about a month, ever since temperatures began to rise. (Express photo by Malhar Mishra)

The fresh waste disposed of at the site while biomining of legacy waste is done turns it into a vicious cycle, said Richa Singh, programme officer, Waste Management Programme, Centre for Science and Environment. As of February this year, the total capacity for processing municipal waste in the city is 5,550 tonnes per day (49.9% of the 11,119 TPD generated). The processing capacity has not increased since at least 2016.

While remediating landfills, waste processing infrastructure needs to be strengthened so that no organic waste reaches the landfill site, said Suneel Pandey, Director of the Environment and Waste Management Division at The Energy and Resources Institute.

“This situation is particular to Delhi. When remediation of waste is being done, there is no alternative site for disposal of waste, and daily waste generation is accommodated at the same site. It would be up to the DDA and the Delhi government to allocate space for the corporations to handle fresh waste so that the remediation of landfills can be done. The remediation is slow, and will have to be done in mission mode,” he said.

Reducing the height of Delhi’s landfills

Why landfills catch fire

The haphazard dumping of all types of waste at these sites means that there have been recurrent fires. There were four instances of fires at landfills so far this summer as temperatures began to rise – three at Ghazipur and one at Bhalswa – that have been difficult to douse. The blaze at Bhalswa, which broke out on April 26, raged for days.

This is because the anaerobic decomposition of organic waste at the landfill generates heat and methane, which is combustible. At Ghazipur, in 2017-18, there were 31 instances of fires, while there were 18 in 2018-19, and six in 2019-20, in “localised, small areas”, going by data provided by the EDMC in September 2020. The one at Okhla did not report any fires during the same period. At Bhalswa, there were 135 instances in 2017, 100 in 2018, 42 in 2019 and three in 2020, the North MCD told the committee in August 2020.

Landfills can have surface and subsurface fires, Singh said. The ones that are difficult to douse are subsurface ones that burn from the inside, since there are pockets of methane in the layers of waste that catch fire, she explained, adding that if the waste is compacted using a layer of soil, it could prevent the formation of these pockets. Besides, a scientifically planned landfill would have a gas collection system and access roads. In absence of access roads, reaching the spots where the fire has broken out to douse it can be difficult, Singh said.

Pandey added: “It’s unduly hot and temperatures of around 37 and upwards… 40 degrees… is ideal for methane generation. In an anaerobic process, at this temperature, the gas generation is maximised. Besides, when remediation is done, the material is excavated from it. Opening up the landfill releases more gas that is already being generated at a high rate.”

The NGT has recently taken cognizance of the fires at Ghazipur and Bhalswa, initiating proceedings based on media reports.

On Ghazipur, the tribunal said in an order on April 22: “It is a matter of concern that such incidents are taking place elsewhere also and there is potential for the same wherever legacy waste remains un-remediated. It is for this reason that the statutory timeline is expected to be followed strictly.”

It added that the dumpsites in Delhi and in other cities are like “time bombs because they constantly generate explosive gases like methane which may escape through vertical and lateral ways posing a constant threat of explosion”.

The landfills also flout the Solid Waste Management Rules of 2016, which state that only non-usable, non-recyclable, non-biodegradable, non-combustible, and non-reactive inert waste should go to a ‘sanitary’ landfill. The “desired objective” is zero waste going to a landfill.

Landfills are also required to have leachate collection and treatment systems, but at Bhalswa, pools of dark-coloured leachate lie around the landfill.

“For a successful biomining operation, the dumping of fresh waste at landfill sites will have to stop. The waste-to-energy plants have their own concerns. We have witnessed failures of WTE plants in India because we put mixed waste, comprising organic waste, into these plants. One thing to do would be to produce compost and biogas from organic waste through decentralised community compost centres or home compost centres. Source segregation should be non-negotiable, and waste generators should share responsibility,” Singh said.

Segregation largely on paper

The Solid Waste Management Bylaws for Delhi, notified in 2018, place the onus of waste segregation – into wet waste (biodegradable), dry waste (non-biodegradable), and domestic hazardous waste – directly on those who generate it, including households. Violators are liable to pay a fine of Rs 200.

However, the segregation of waste at source is being implemented in just 32% or 94 out of 294 wards, according to the Economic Survey of Delhi 2020-21. The practice is prevalent mostly in the New Delhi Municipal Council and Delhi Cantt areas where 22 wards segregate waste, while in the remaining areas, just 72 out of 272 wards (26%) segregate waste.

This, even as the three MCDs claim to have made a push in this direction.

Former South MCD Mayor Narender Chawla said that the civic body on its behalf can try repeatedly but for it to be completely successful, cooperation of the public is important. “We are reaching out to RWAs to segregate at home, and compost at the colony level, because that’s the best practice to ensure minimum waste reaches landfill,” he said.

Senior officials, however, said that penalty provisions should be introduced for the model to be successful for which they do not get permission from the political wing. A senior leader in the MCDs said, “Every year there are elections which create pressure on us to not take any such measure that could disappoint people.”

The three MCDs claim that over 8,000 tonnes of waste is processed per day with trommel machines installed at the sites. A senior EDMC official said that fresh waste of 2,500-2,600 TPD is dumped at the site, and 20 trommel machines have been installed. The machines can process up to 3,600 tonnes of legacy waste daily.

The corporations have also fared poorly when it comes to waste management surveys, the latest being one by the Ministry of Housing and Urban Affairs (MoHUA) in which the North and East MCDs have once again finished in the bottom 10 among cities with a population of over 10 lakh.

Senior officials in the three corporations said that a new ‘engineered’ landfill and WTE plant coming up at Tehkhand, increasing the bio-mining of legacy waste, another WTE plant at Rani Khera, and biomethanation plants are on the anvil to speed up the landfill flattening project.

Biomining, however, comes with its issues. The process hits a lull when there is rainfall. Besides, a senior EDMC official said the inert material generated after the waste that is put through trommels does not have too many takers as there is a perception that materials produced from it, like bricks, are of inferior quality. The three MCDs are in talks with the NHAI for taking it.

While an SDMC official said that 20 trommels are deployed at Okhla, the North MCD has deployed 40 trommels that clear 300 tonnes of waste daily at Bhalswa, including six high-speed trommels that process 600 TPD, said a senior official of the North MCD.

The environmental damage, and consequently, the damage caused to people in the vicinity of these landfills, is enormous. “The leachate generated from these landfills that are more than 20 years old has already contaminated the groundwater. Landfills pollute the air when they burn, and through uncontrolled methane emissions even when not on fire,” Pandey said. Methane is a greenhouse gas. Landfill gas includes methane, carbon dioxide, nitrogen and hydrogen sulphide.

Water in borewells near Bhalswa and Ghazipur was found to contain cadmium, copper, chlorides and total dissolved solids in excess of permissible limits in 2019, according to a report submitted to the NGT by the committee that was constituted to determine the impact of the landfills on the environment. High levels of chemical oxygen demand and iron was reported in ground water at all three sites, “which may be due to leachate from the dumpsite,” according to the report.