Plan to flatten landfills in Delhi may be delayed after record monsoon
The heavy monsoon in the national capital this year may interfere with the Delhi municipal corporations’ target of flattening their three major garbage dumps by September 24, officials of the civic bodies said.
According to reports submitted to the National Green Tribunal (NGT), the three corporations expect to clear one landfill each over the next three years.
A senior official overseeing the sanitation department in the South Delhi Municipal Corporation said trommel and bio-mining work has been halted for the past two months due to the rain.
“Waste cannot be sieved when wet. So, various components of waste cannot be separated using trommels,” the official explained.
Bio-mining through trommel machines separates various components of legacy waste such as plastic, paper, cloth, sand, bricks etc. Excavation and mining of the old legacy waste is carried out and it is fed into the main trommel through a conveyor belt. The trommel consists of a cylindrical rotating sieve while air is blown from one end to the other. Heavy stuff like soil, stones fall closer through the cylindrical sieve while lighter components like plastic/paper fall at the farthest end. The various components of mixed waste can also be separated based on varying size or sieves or holes in the trommel machine.
Since June 1, the city has received over 1,169.7mm of rainfall this monsoon. The city had received only 404.3mm of rainfall during the 2019 monsoon and 576.6mm rain in 2020.
The Okhla landfill in south Delhi holds an estimated 5.64 million metric tonnes (MT) of legacy waste, and data from the civic body shows that approximately 630,000 MT of this was removed before the onset of monsoon this year.
A north corporation official overseeing the bio-mining project at the Bhalswa landfill confirmed that trommeling has been stopped due to rain.
“The trommel machines cannot operate with wet waste, and progress has been very slow over the past 2-2.5 months. This may cause further delays,” the official said.
The Bhalswa landfill site is estimated to hold eight million tonnes of legacy waste and according to the affidavit filed with the NG, the north body has set a deadline of March 2023 to flatten the site.
Similar problems are being faced in East Delhi which houses the largest landfill site in the city. EDMC Mayor Shyam Sunder Agarwal said that no trommeling can occur during the rainy season. “We are trying to somehow continue with the project by using excavators to dig dry legacy waste. We are looking to develop tin sheds so that the project can be continued even during the monsoon season. We are still targeting to clear the landfill by 2024,” he added.
The SDMC official said areas under the south Delhi civic body generate around 3,600MT of garbage every day, of which 50% is processed in facilities like waste-to-energy plants, while the rest is dumped on the Okhla landfill site.
“We are planning to process 100% of waste by June 2022, after which no fresh waste will be dumped on the Okhla landfill. Legacy waste will be bio-mined much faster after this,” the official said.
The trommeling and bio-mining of mixed legacy waste leads to separation of various components like boulders, soil, organic matter, plastic, clothes etc. The south body official explained that around 70-80% of legacy waste comprises stones, boulders and inert material, while the rest is combustible component like plastic, cloth etc. The three municipal corporations have been facing problems disposing inert material due to a shortage of space.
In a bid to tackle the problem of removal of waste components generated after the sieving and bio-mining, the civic body has hired 13 agencies to utilise the combustible refuse-derived fuel (RDF) component like plastic, cloth and others.
“We are in contact with the National Highways Authority of India (NHAI) to use the inert soil during the construction for the Urban Extension Road, as well as a stretch near the Delhi-Noida Direct Flyway and in Faridabad. The inert material is also currently sent to parks being developed in Tajpur Pahari and Eco Park in Badarpur,” the official stated.