Sensors, cameras at Delhi landfills in MCD plan to prevent fires

With temperatures set to rise, the effectiveness of these measures will be put to the test in the coming weeks.

Temperature sensors, expansion of CCTV camera network, and spark arresters in trucks are just some of the measures the Municipal Corporation of Delhi (MCD) has undertaken in an attempt to reduce fires at the three garbage mountains in Delhi, officials aware of the matter said on Wednesday.

The efforts come a year after a massive fire broke out at the Bhalswa landfill in April 2022 when the site burnt for days on end. (Sanjeev Verma/HT Photo)

The efforts come a year after a massive fire broke out at the Bhalswa landfill in April last summer when the site burnt for days on end.

With temperatures set to rise, the effectiveness of these measures will be put to the test in the coming weeks. A senior municipal corporation official from the sanitation department said that the fires at the landfill sites are caused due methane emanating from the decomposing organic municipal waste.

“During summer, the rate of methane generation increases, and rising temperatures cause the build-up of trapped methane inside the layers at landfill sites. It is a natural phenomenon so our strategy mostly focused on early detection of small fires which can be doused before it goes out of control,” the official said.

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Last year, around 20 instances of small and big landfill fires were reported and the inferno at Bhalswa dumpsite lasted for more than a week, making it the biggest such episode in the last decade. Nearly 10 fire tenders of the Delhi Fire Services (DFS) were rushed to control the blaze at the time in April 2022.

A second municipal official said that the civic body has developed an adequate network of CCTVs to continuously monitor the three landfills – Okhla, Ghazipur and Bhalswa – from all sides. “Thirty-one CCTV cameras are operational at Bhalswa, 35 at Okhla, and 22 at Ghazipur, to which ten more cameras are being added. The footage from these cameras is being monitored at the respective engineer’s office at the site,” the official added.

Taking cognisance of the repeated fires, the National Green Tribunal (NGT) last year constituted a committee, chaired by Justice SP Garg, a former judge of the Delhi high court, to make recommendations to prevent such incidents. Among a series of recommendations, the panel also mandated the installation of spark arresters in trucks and heavy machinery operating at landfill sites to prevent the possibility of fire.

MCD, in an official response, said that “All the vehicles coming to sanitary landfill sites for disposal of garbage and segregated material are now equipped with spark arresters”.

Spark arresters are added to the exhaust system of vehicles and each unit of the device costs between ₹2,000 - ₹3,000. An official said that earlier, a majority of these vehicles were operating with catalytic convertors and did not need the arresters. “All remaining old vehicles have been covered with the devices,” the official added.

The civic body said that the Bhalswa and Ghazipur landfill sites now also have temperature sensors to monitor the inner temperature of the landfill as an early warning system. Besides temperature monitoring, the NGT panel had also recommended carbon monoxide monitors, methane detectors, and fire alarm systems which remain works in progress.

During the vulnerable period in summer, the civic body plans to deploy 26 personnel to monitor the three mountains and additional electricity poles are being added to increase illumination for surveillance during the night, the official said.

There are four water tankers at each mountain. “The fire department has also provided a dedicated fire tender at the nearest station to reduce the response time. We have also held joint drills and training between MCD and the fire department,” the MCD spokesperson said.

SK Tomar, divisional officer, DFC, said that the landfill fires are challenging because of the inaccessibility due to the height of the dump, the scale of flammable material, and the continuous supply of flammable gases.

“The fire is caused due to a mixture of flammable and poisonous gases generated by waste decomposition such as hydrogen sulphide, methane, and other hydrocarbons. The bigger fire tenders cannot climb the dumpsite while the smaller 4,000-litre ones cannot extinguish the flames,” he added.

Tomar said that the ideal preventive step to control such fires is only landfill management by developing layers of sand and debris over fresh waste and developing green cover.

“We have two dedicated fire tenders and their staff only to tackle landfill fires. They are present at the nearest stations to three sites and remain exclusively earmarked for this purpose,” added Tomar.

Besides being indicators of an acute waste management crisis, Delhi’s landfill sites also contribute significantly to its air pollution. Toxic fumes that the landfills emit include greenhouse gases like carbon dioxide, carbon monoxide, hydrogen sulphide, dioxins, and furans.

Bharati Chaturvedi, environmentalist and founder of Chintan Environmental Research and Action Group, said that water sprinklers and prevention steps are a little too late for the scale of the problem when the organic waste has already landed at the sites.

“We have had several fires in recent years. Instead of sprinklers, we should invest money in neighbourhood composting by developing infrastructure, three-month running costs, and a buy-back scheme for compost. These can ensure the viability of wet waste being treated. Hotels already do it and it needs to be expanded on an urgent basis to residential areas. It is harder to get space for such composting units,” she added.

The challenge in tackling such fires is higher due to the height and slope of the landfill sites. The steep vertical surface makes these sites inaccessible, while the source of the fire is located 10-20 metres below the surface. This means that using water would increase the problem, as due to the porosity of the landfill, the dry parts also become active and decrease the stability of the structure.