Deonar dumping ground bioremediation raises fears of lethal gas leaks

MUMBAI: A Govandi-based residents’ welfare body has demanded an immediate halt to the alleged fresh waste dumping at the Deonar dumping ground as well as a time-bound plan for its scientific closure

MUMBAI: A Govandi-based residents’ welfare body has demanded an immediate halt to the alleged fresh waste dumping at the Deonar dumping ground as well as a time-bound plan for its scientific closure. The body has warned that the excavation of nearly 185 lakh tonnes of legacy waste, which is currently being undertaken to free the space for housing for the Dharavi Rehabilitation Project, could expose surrounding neighbourhoods to hazardous gases if adequate safeguards are not in place.

Deonar dumping ground bioremediation raises fears of lethal gas leaks. (Raju Shinde/HT)

In a legal notice dated October 26, the Govandi New Sangam Welfare Society has asked the BMC, Maharashtra Pollution Control Board (MPCB) and Mumbai police commissioner to comply with its demands within 14 days, failing which it will approach the Bombay high court and the National Green Tribunal (NGT).

Local corporator Zameer Qureshi said that the nearly century-old waste mound, which is about 20 storeys high today, poses a serious concern during excavation. “Around 18.5 million tonnes of garbage have to be shifted,” he said. “Methane, ammonia and sulphur dioxide are present beneath it and they could be released into the surrounding areas, where there are residential settlements.”

Qureshi said that around 1,65,000 residents from Govandi’s M East wards 134, 135 and 136 would be the most affected. “The BMC’s tender must provide for gas-collection points to contain the gases,” he said. “They must be collected using appropriate technology.” Qureishi alleged that the safeguards recommended in reports by the NGT and MPCB were not in place and nearly 500,000 residents could be affected by this.

The society has demanded a binding order prohibiting fresh municipal waste from being dumped at Deonar and its diversion to designated scientific processing facilities. It has also sought a legally enforceable, month-wise action plan for biomining legacy waste, methane extraction and flaring, leachate treatment and environmental restoration of the 110-hectare site.

The notice further seeks public disclosure of ambient air-quality data, methane-monitoring readings, water-testing reports and MPCB compliance records. It calls for real-time pollution monitoring, dust suppression and odour-control measures along the boundaries adjoining Govandi and Mankhurd besides stricter enforcement against illegal waste burning and dumping.

The MPCB has also laid down environmental safeguards for the project, covering dust and odour control, fire prevention, methane hazards, slope stability and leachate management. It has mandated periodic ambient air quality monitoring, transportation of waste in covered vehicles and additional precautions during the monsoon to prevent waste or eroded material from entering nearby drains or spilling into adjoining areas.

Shaikh said the issue extended beyond the dumping ground to the right of residents to live in a healthy environment. “If the Deonar dumping ground is not shut down and methane gas collection points are not installed, it will represent a grave failure of the system to protect public health,” he said. “We will not remain silent. If necessary, we will launch a massive people’s movement to fight for the complete closure of the dumping ground and the right of Govandi’s residents to breathe clean air.”

The BMC, however, denied that fresh waste was being dumped at Deonar. “There is no question of methane gas emissions in Deonar as the bioremediation is in process,” said Kiran Dighavkar, deputy municipal commissioner, solid waste management. “Methane is emitted from dumping fresh waste and, at present, this has stopped in Deonar, with fresh waste diverted to the Kanjurmarg dumping ground. We have appointed environmental and technical experts, and whatever MPCB guidelines are stipulated will be strictly adhered to. All precautions will be taken.”

In a compliance report submitted to the MPCB on June 27, 2025, the BMC had stated that around 350 gas vent pipes had been installed at various locations across the dumping ground. It also reported that methane-monitoring work was being undertaken and that water-sprinkling systems mounted on tankers, along with a fogger cannon, were being used to control dust.

The civic body had said that a detailed bioremediation and scientific closure plan was being finalised. The report was submitted in response to interim directions issued by the MPCB on January 15, 2025, under the Water Act, 1974, the Air Act, 1981, and the Solid Waste Management Rules, 2016.

Meanwhile, Navayuga Engineering Company, which is undertaking the bioremediation biomining and land-reclamation project, reported that six processing machines with a combined capacity of 1,800 tonnes per hour had been commissioned at the site by October 14. A trommel screener with a capacity of 100 tonnes per hour was also operational, while two additional machines were expected by November 15. The project aims to process 18.5 million tonnes of legacy waste and reclaim 110 hectares of land.

The company has also reported installing air-quality monitoring equipment, laboratory facilities and a leachate treatment plant. Its status report lists November 30, 2026 as the expected date for a further no-objection certificate without specifying the nature of the clearance.

The Govandi residents’ group has alleged violations of the Solid Waste Management Rules, 2016, the Environment (Protection) Act, 1986, and the Air(Prevention and Control of Pollution)Act, 1981. It has warned that it will approach the Bombay high court and the NGT’s western zone bench if its demands are not met within 14 days, and may seek accountability under the Polluter Pays principle.