TERI flags high surfactant levels, ammonia and microplastics in the Yamuna
Identify hotspots, prepare time-bound implementation plans: Environment minister
A view of the toxic foam in Yamuna river. (Express photo by Gajendra Yadav) As surfactants from detergents continue to enter the Yamuna unchecked in the absence of regulatory limits, a new study by The Energy and Resources Institute (TERI) has identified multiple hotspots along the Delhi stretch of the river where untreated sewage, industrial effluents and solid waste are contributing to frothing, chemical contamination and a rising microplastic load.
The study, presented to the Delhi government on Tuesday, is based on nearly 100 water samples collected from more than 50 critical locations, including major drains, industrial clusters and sewage treatment plant (STP) outlets, during pre- and post-monsoon seasons.
A copy of TERI’s department-wise action plans or recommendations, accessed by The Indian Express, calls for continuous monthly monitoring of the Najafgarh and Shahdara drains and all major STPs and common effluent treatment plants (CETPs) for microplastic contamination, strict penal action against non-compliant treatment plants, and the installation of real-time plastic-pollution dashboards to track waste flows across the city. It also urged the government to plug untreated sewage discharges by completing drain-tapping projects and to upgrade underperforming STPs with advanced oxidation processes and biological nutrient removal technologies, needed to tackle the rising load of detergent chemicals and ammonia that current treatment systems struggle to remove.
The findings were reviewed at a high-level meeting chaired by Environment Minister Manjinder Singh Sirsa, where elevated levels of surfactants, organic pollution, ammonia and microplastics at several discharge points along the river were flagged. As the winter sets in and the Yamuna’s flow naturally dips, pollutants in the river become more concentrated, making the annual frothing more visible. When untreated sewage carrying both industrial laundry effluents and household discharge — including detergent-rich wastewater with high levels of surfactants — enters the river, they get vigorously agitated as the water falls over barrages. The turbulence traps air and reduces the water’s surface tension, causing bubbles to form quickly and accumulate as thick, persistent foam.
Sirsa directed all departments to examine TERI’s recommendations, identify priority hotspots and prepare time-bound implementation plans, and announced that a specialised inter-departmental coordination cell will be set up “to ensure integrated planning, execution and monitoring of Yamuna cleaning measures”. His office quoted him as saying: “I have instructed the departments to work in close coordination and remove procedural bottlenecks so that the people of Delhi can see visible changes on the ground at the earliest.”
Senior Delhi Jal Board officials, meanwhile, said the city currently has “no facility to treat excess amounts of surfactants” and that detergent content remains a “significant issue” driving frothing. “It will take a long time to control surfactants unless there is a determined limit for surfactant levels,” an official said, adding that six-eight STPs have been upgraded in recent months and the remaining are expected to be strengthened by December 2027.
Delhi-based environmental activist Pankaj Kumar said the continued absence of any regulatory cap on surfactants is rendering even upgraded treatment plants ineffective in tackling foam formation. “There is no limit set for surfactants. There has to be a national-level policy to set a maximum limit, and the government must also intervene at the manufacturing stage to ensure detergent formulations reduce surfactant content,” he said.
Pointing to the Rithala 40 MGD Phase-II STP, which is one of the facilities upgraded to meet the latest Central Pollution Control Board norms, he said, “If frothing would have stopped just by upgrading, then the treated water coming out of Rithala STP would not have frothed. The plant shows compliance in DPCC reports, but the treated water coming out is still heavily frothed. This shows that the problem cannot be solved without regulating surfactants.”
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