Perched atop a truck under the bright afternoon sun, 50-year-old Pramod Mandal moves swiftly, stacking freshly harvested cauliflowers one over the other as workers below pass up basket after basket. The 20-acre field in southwest Delhi’s Dichaon Kalan operates with a quiet efficiency – a ladder propped against the truck, men climbing up and down in rapid succession, the vehicle gradually filling up with what will soon be nearly 30 quintals of produce bound for mandis in Keshopur or Azadpur.
Just beyond the field, the Mungeshpur drain – a supplementary channel of the Najafgarh drain snakes past in a near-pitch-black stream, its surface heavy with industrial effluents. While Mandal is reliant on groundwater, there are plenty of farms in the area which are using water directly from this drain to irrigate their fields.
Mandal, who has been cultivating cauliflower here for nearly three decades, says the crop has become the backbone of farming in the area. Paying ₹70,000 annually to lease the land, he earns around ₹15,000 per truck, managing profits of close to ₹5 lakh a year. “Cauliflower grows easily. It is hardy and can survive even in tough conditions. The yield is good too,” he said.
While borewells remain the primary source of irrigation, the proximity of the drain offers a fallback — albeit a troubling one. “The water in the drain is terrible, so we try not to use it. However, some farmers are forced to use it in areas where the groundwater is saline,” he said.
Across the drain, 40-year-old Meena Kumari tends to her patch of spinach and cauliflower, recounting how a breach in the drain during heavy rains in January inundated her fields. “The produce ended up growing in this water. We were able to salvage most of it, but the water is terrible, and it stinks,” she said.
Dichaon Kalan has, in the past 15 to 20 years, witnessed an agricultural push, emerging as a cauliflower hub supplying vegetables across Delhi. Krishan Kumar, who has run a dairy here for 11 years, describes the shift as organic but sweeping. “They used to be grown here even when I started my dairy, but it is like a domino effect. More and more farmers have seen and adopted the same crop. Truckloads of cauliflowers go from Dichaon Kalan to all parts of Delhi – Najafgarh, Okhla, Azadpur – you name it,” he said.
But the transformation carries an environmental cost that runs just alongside these fields. A short drive away in neighbouring Jharoda Kalan, the pattern repeats itself – stretches of cauliflower fields interrupted occasionally by cabbage, all lining the dark, sluggish drain. “There are parts of Jharoda Kalan, like across this road where salinity is so high, that farmers only use water from the drain,” Babloo Kumar, 25, said.
While the drain here is a darker shade of brown, sure enough, HT was able to spot multiple pipes entering the drain, with the sound of motor pumps running. In a small 50-metre stretch, over 10 pipes from different fields could be seen entering the drain, pumping out this highly polluted water into the fields.
These pipes pull up drain water at one end, run under the road and emerge again in the field located on both sides to feed with a constant supply of water. HT saw dozens of instances of fields being irrigated using the untreated drain water along this belt.
Scientific assessments, however, paint a stark picture of the risks involved.
Multiple studies conducted over the past decade by IIT-Delhi researchers across five locations along the Najafgarh drain have detected heavy metals – chromium (Cr), copper (Cu), cadmium (Cd), zinc (Zn), nickel (Ni) and lead (Pb) – in concentrations ranging up to 50 times the permissible limits set by the Food and Agriculture Organization (FAO), rendering the water unsuitable for irrigation.
A 2020 study titled “Assessment of Drain Water Used for Irrigation in the Delhi Region” in JH&P journal concluded that consumption of heavy metal-contaminated agricultural products can cause deleterious human health effects, leading to further health problems.
Experts said agriculture along the Najafgarh drain is being watered with untreated mix of industrial and domestic wastewater. “This is likely causing long-term accumulation of heavy metals and lead in soils and eventually the crops,” Priti Mahesh, an independent environment and public health researcher, said.
Farmers have demanded an alternative clean sources of water, either through canals or other outlets.
Experts point to a structural gap driving this dependence. “There are several farmers that are using water from the drain, as unlike Haryana or Uttar Pradesh, we do not have proper irrigation channels or canals. If the farmer cannot use groundwater, he will end up using this highly polluted water,” said Paras Tyagi, an activist with NGO CYCLE India.
Bhim Singh Rawat, Yamuna activist and member of the South Asia Network on Dams, Rivers and People said if only sewage was used to irrigate fields, it does act as manure to an extent, however, Delhi’s drains, including the Najafgarh drain are carrying a mix of sewage and effluents.