Abu Talib points at the mountain of waste on fire and the grey cloud of smoke that has obscured the blue sky over the Indian capital, Delhi. “Almost every summer [for] the last few years, this has been happening,” he says.

We are standing on the edge of an open drain choked with household waste in Ghazipur, to the east of the city. Plastic, paper, sanitary napkins and everything else is stuck in the water drain, preventing it from flowing as it should.

Ghazipur, one of Delhi’s three designated landfills, is supposed to deal with the waste generated by the whole city. Instead, it is struggling with its own.

In the early heatwave that has hit northern India with temperatures of 47℃, the area smells of rotten potatoes and rotting carcasses. Talib blinks furiously and covers his nose and mouth with extra layers of scarf to avoid breathing in the toxic air.

Talib has lived in Ghazipur since 1985, a year after the Delhi government decreed the area would be used as a landfill. But now, “it's not even a landfill, it has become Ghazipur’s dumpyard,” says Gaurav Paul, a waste management expert and regional operations manager at Plastics for Change, a non-governmental organisation. ”In a landfill, you treat the waste scientifically. In a dumpyard, you just keep piling [up] the waste," he adds.

Ghazipur reached its capacity to accommodate waste in 2002 but 2,500 tonnes continue to be dumped in the landfill every day. In 2021, the trash pile was slashed by 12 metres after it had grown to a 65-metre high “mountain of shame”, a strange topographical feature in Delhi’s flat terrain. On occasion – three times since March – the mountain catches fire, something experts say could be on account of increased amounts of methane generated by the towering pile of decomposing waste. If methane crosses a certain concentration, a fire is ignited. But it may not be as simple as that.

“In the beginning, there was no problem, but then in the last 10-15 years, there is stench, diseases, water problems, occasional fires and whatnot,” Talib said.

But Ghazipur is not the only trash mountain on fire in India, or even in Delhi.

Bhalswa, the second of three landfills that take Delhi’s daily 10,000 tonnes of garbage, caught fire at the end of April. It reached capacity in 2010, as did Okhla, the third landfill.

Other than landfills, Delhi does not have a system of waste disposal and treatment, so all three of the city’s overburdened landfills remain operational.

Akhilesh Kumar, executive engineer of East Delhi Municipal Corporation (EDMC), which is responsible for public sanitation, maintenance of sewage and waste disposal, says attempts are underway to flatten the mountains of waste. But Azmat Noor, who has lived near the Ghazipur landfill for decades, says that even if the mountain is becoming a bit shorter, the site seems to be expanding.

The landfills are a fire hazard and are also making the Indian capital’s heavily polluted air much worse.

If it's not the fire, it's the smell. Residents say it has become a trademark of Ghazipur. “When visitors come to our houses, they comment, ‘What kind of hell do you live in?’” says Maheshwari, a local resident whose house looks out on the dumpyard. “Most of them have just stopped visiting. Who wants to smell the rubbish? But who listens to us?” The fires, however, do make headlines, in India and abroad. A fire in a landfill is different from other fires because it is hard to douse and produces more toxic gases.

Ghazipur’s residents feel the toxic effects of their polluted neighbourhood. Sevanti Devi says her children suffer from a constant cough and cold. Another local resident, Seema Kumari, says there has been no water in the area for three months and her hands hurt from drawing water from the hand pump. Locals claim the lack of water is down to government tankers no longer delivering to the area. Given the chance, locals avoid drinking the groundwater, because in Kumari’s words, “ we often end up in hospital.”

The leaching of the waste can affect the groundwater, agrees Sahana Goswami, an urban water resilience programme manager for the non-profit World Resources Institute India. But there isn’t enough data to conclusively prove the effect of these landfills on the people who live around the sites, she adds. More is needed.

“Most of the people living around these sites are poor, disadvantaged and vulnerable, but the impacts are not limited to them. The impact extends to everyone living in the city and beyond,” said Goswami.

However, Chanchal Pal, an ear, nose and throat doctor in Delhi, who studies the impact of pollution on health, says the effects are very obvious. “When you burn the garbage, it leaves out a lot of smoke and when you burn plastic it leaves out a lot of nitrofluorene, which are known to be cancerous fumes. There is no doubt that there is a health hazard.” The smoke is a “slow poison”, she says, which affects the nose, skin, hair, lungs and kidneys, because “as microparticles, the toxins reach the blood and get deposited in various parts of the body”.

Talib and other Ghazipur residents speak about a ‘zehrilli’, a poisonous gas. Not only is it toxic for humans, it repeatedly causes fires, they say. The gas in question is methane, which is highly inflammable.

Kumar, the EDMC engineer, agrees that the landfill sites produce a lot of methane, which might lead to fires. “But we still don't know the real cause,” he adds. “The recent CCTV cameras show fire igniting even without any spark.”

Euan Nisbet, professor of earth sciences at Royal Holloway, University of London, says methane can self-ignite at a very high temperature but questions whether that is happening at the landfills. “Since the methane generated in a landfill site is produced naturally by microbes, the maximum such an environment can reach is up to 110-120℃ ,” he explains. Nisbet says “most of the fires are human-induced. But it's not to say that these fires are intentional. Methane can catch fire even from a cigarette bud. Which are everywhere.

“In dumpsites like these, where glass bottles lie unattended, they can also lead to convex sunlight effect leading to spark.”

Nisbet added: “You can think of methane as the cooking gas that you use in your kitchen. When you switch on the stove, the gas releases and with the introduction of a little spark it catches fire quickly.”

Digamber Chavan, an environmental researcher who has been studying India’s landfills since 2017, says that old waste itself could fuel a fire, with methane serving as a catalyst. Fresh waste can catch fire at 280℃, he says and old waste can catch fire at 160-180℃, but it can start to smoulder at a much lower temperature. “Once the smouldering begins, the abundant methane nearby catches fire readily,” says Chavan.

But the Delhi authorities continue to focus on waste that is just a couple of years old, in the belief that older trash does not have the potential to catch fire.

While the reason the landfills catch fire is disputed, there is little doubt that methane plays a role. At COP26 in Glasgow last year, more than 100 countries joined the Global Methane Pledge, which aims to rapidly reduce the production of methane. But India stayed away.

Experts say that India can reduce the amount of methane it produces. Just addressing the landfill issue will make a difference, says Nisbet. “It’s not so difficult or expensive.”

A landfill can be capped with soil, to prevent the methane from leaking out, say experts. New systems can be introduced to segregate the waste at the source. “Other Indian cities like Indore and Hyderabad have already worked on these solutions,” says Paul, the waste management expert at Plastics for Change. “In the waste hierarchy, landfill should be the last option.”

Until 2000, India did not have waste management regulations nor does it have regulations to treat legacy waste.

"The waste that lies here is 50-70 years old… 2,80,000 tonnes of legacy waste,” says Paul.