Winter rain causes leachate run-off from Bandhwari landfill

Gurugram Residents of villages around the Bandhwari landfill have reported leachate run-off from the landfill since the spells of rain that hit the city from January

Gurugram Residents of villages around the Bandhwari landfill have reported leachate run-off from the landfill since the spells of rain that hit the city from January 17. An HT team, on its visit to the spot on Tuesday evening, found large pools of black liquid collected just outside the boundary of the landfill, which is spread over 27 acres and located 20 kilometres from the city.

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Sunil Harsana, an activist from Mangar village, which is located adjacent to the landfill, said that these pools formed immediately after last week’s rains and the run-off was entering at least one surface water body located behind the landfill. HT also verified the claims by visiting the water body.

According to Ecogreen Energy, however, the pools are “not entirely leachate.” A spokesperson for the company, which is the MCG’s concessionaire for waste management, said, “This is largely rainwater that is flowing out of the landfill. We have lined the entire dump with SPV (high-grade plastic) to prevent rainwater mixing with leachate and the rainwater is channelled outside. Still, there might be some mixing of leachate and rainwater happening and we are taking steps to fix this.” Leachate refers to water that has percolated through a solid, through a process wherein it ‘leaches’ out some of its constituent elements. In the case of unsanitary landfills, such as the one in Bandhwari, leachate typically constitutes heavy metals and other bacteriological toxins present in mixed municipal waste.

The spokesperson said that Ecogreen is currently processing about 150KLD (kilolitres per day) of leachate, at its leachate treatment plant, inaugurated in August 2018. The recycled water is then sent to a plant in Behrampur for further treatment. “In addition to this, we have installed one 200KLD disc tube reverse osmosis (DTRO) unit, and are waiting for certification from a lab. That will be sent to the MCG and we will make the DTRO plant operational soon. A second DTRO plant has also been commissioned and should become operational by March.”

The spokesperson added that with the use of these DTRO units, the recycled water would conform to more rigorous quality standards and could be discharged into the surrounding forests without concern. “The water can also be used directly for agriculture. In any case, the quantum of leachate produced by the landfill at this time of the year would be much less than during monsoon, when there is a lot of atmospheric moisture content,” he said.

The “leachate problem” at Bandhwari is alleged to have degraded the water table in the region, thus, posing a health risk to locals who rely on it for drinking and other domestic purposes. The issue of landfill run-off in the region has persisted for close to a decade and routinely worsens every monsoon. However, with bouts of sporadic rain this winter, the issue has cropped up at an unlikely time, environmentalists pointed out.

It has also been alleged that leachate is polluting the groundwater as well as surface water bodies in the Aravallis. A 2015 survey by Rekha Singh, an approved environment expert from the Quality Council of India (ministry of environment, forest & climate change), highlighted this concern.

Singh had tested samples from a leachate pond inside the landfill and found that the count of total dissolved solids (TDS) in the water was 6,950 mg/l, which is much higher than the permissible limit of 2,100mg/l, according to the Municipal Waste Management Rules, 2000.

“The contamination from the leachate pond has started polluting the groundwater, causing serious fluoride, phenolic compound, cadmium and mercury poisoning,” Singh said in her report.

In 2017, an inspection by a team from the Central Pollution Control Board found that the groundwater in Bandhwari contained iron, manganese, boron, calcium, chlorides and nitrates in excess of India’s drinking water standards (IS 10500:2012).

Another report in August 2019, by the National Environmental Engineering Research Institute, suggested that contamination from the landfill has likely spread downstream via the underlying aquifer, to the neighbouring villages of Mangar, Baliawas and Gwal Pahari.

Groundwater samples from 14 locations within a five-kilometre radius of the landfill were found to be “highly contaminated”, with pathogenic bacteria and heavy metals in excess of India’s drinking water quality standards.

“This is a preliminary report and nowhere does it say that the contamination is due to the landfill,” MCG’s sanitation inspector, Saurabh Nain, had said last month.

However, Nain did not respond to messages and calls seeking comment on Tuesday. MCG commissioner, Vinay Pratap Singh, could not be reached despite multiple attempts, while Kuldeep Singh, the HSPCB’s regional officer in Gurugram, did not respond to messages and calls seeking comment.