By: Express News ServiceNew Delhi | December 25, 2025 05:46 AM IST 3 min readThe group has urged the DPCC to initiate proceedings against DJB and impose environmental compensation under the “polluter pays principle”, with the funds to be used for remediation and restoration of the Yamuna.Environmental activists have written to authorities flagging ecological risks stemming from what they alleged was ‘prolonged spraying of defoamers’ to rid Yamuna of its froth this season and sought action against officials.In the latest letter sent earlier this week to Lieutenant Governor (L-G) V K Saxena, Chief Minister Rekha Gupta, Delhi Pollution Control Committee (DPCC), Delhi-based environmental group Earth Warrior has urged DPCC to take action against the Delhi Jal Board (DJB) for carrying out “prolonged, excessive and unregulated” spraying of silicone-based defoamers downstream of the Okhla Barrage from mid-October 2025 for over two months.The group maintained that the prolonged spraying of defoamers in 2025 marked a departure from the shorter duration of spraying observed in the previous years. While highlighting that the use of defoamers in the last three years–between 2022 and 2024–was restricted to around 7-10 days during the Chhath Puja period, the group alleged that in 2025 the spraying began in the second week of October and continued well beyond November, including on days when little or no visible foam was present on the river surface.In its complaint to the DPCC, Earth Warrior claimed that large quantities of defoamers were sprayed without prior environmental clearance, scientific risk assessment, or publicly disclosed dosage protocols.The group cited international peer-reviewed studies suggesting that excessive use of polydimethylsiloxane (PDMS), a key component of many silicone-based defoamers, can form hydrophobic surface films that interfere with oxygen transfer and cause hypoxia – a condition marked by low levels of oxygen in body tissues – apart from acute and chronic toxicity to fish, invertebrates and benthic organisms.The letter also flagged the risk of sediment contamination, bioaccumulation and disruption of microbial processes, which, it said, could further compound the river’s existing pollution load.The group has urged the DPCC to initiate proceedings against DJB and impose environmental compensation under the “polluter pays principle”, with the funds to be used for remediation and restoration of the Yamuna.Story continues below this adIt has also sought an independent assessment of ecological damage, including water-quality monitoring before and after the spraying, sediment analysis, and evaluation of impacts on aquatic life.Last month,the group had written to L-G V K Saxena and Gupta, among others, raising concerns over the prolonged use of silicone-based defoamers to prevent frothing in the Yamuna. Following repeated representations, the DJB has now ceased the defoaming operations, the group claimed.Meanwhile, a senior DJB official said defoamer dosing is typically determined by factors such as foam thickness, bubble size and whether the foam is compact or loose. There was no immediate response from the agency on the specific ecological risks flagged by the activists. Stay updated with the latest - Click here to follow us on Instagram© The Indian Express Pvt Ltd