Microplastics (MPs) are plastic particles that have a size range from 100-5000 µm and originate from various sources, including synthetic textiles and the breakdown of larger plastic waste. Over the last decade, the occurrence of MPs in subsurface environments and different water bodies has received significant scientific attention. The Yamuna River stretch in Delhi is under an environmental threat due to discharged pollutants and these pollutants in terms of plastic waste make India a major global contributor in generating plastic waste of over 8-12 million tons per year.

In February 2023, the Department of Environment (DoE), Government of National Capital Tertiary of Delhi (GNCTD), awarded a project to The Energy and Resources Institute (TERI) to study MPs in the Yamuna River and Groundwater in Delhi. This report by TERI is amongst the first of its kind detailed scientific and geospatial analyses to identify and characterize MPs in the Yamuna River Water. This report aims to provide new information to decision-makers, government authorities, and stakeholders to help them to formulate policy measures to mitigate the MPs pollution in freshwater systems in Delhi.

The Yamuna River in urban Delhi for a span of approximately 22 kilometers, a mere 1.5% of its total length, flows from Wazirabad to Okhla and is one of the most severely polluted segments of River Yamuna. Along with other problems Yamuna River stretch in Delhi grappling with the persistent and concerning issue of foaming, drawing a lot of attention from authorities, researchers, and concerned citizens.

In this regard, the Department of Environment, Government of NCT, Delhi, awarded TERI the project "Study of Frothing in River Yamuna in Delhi" in February 2023. The Energy and Resources Institute (TERI) bagged the project, underscoring its expertise and commitment to environmental research and solutions. This study aims to identify the reasons behind the foaming/frothing in Yamuna River; identify froth sources in various drains including Najafgarh Drain (upstream Dhansa Regulator to Wazirabad) and supplementary drains; and find out parameters exceeding the standard permissible limits; identify areas sources such as colonies, industrial areas, etc., contributing to the pollution load responsible for frothing in Yamuna and finding out the relative quantification, nature, source and characteristic of the pollutants and identify hotspots, and to develop a short-term, medium-term and long-term action plan including clear enforcement strategies for minimizing frothing/foaming in river Yamuna. Thus, overall work involved sampling during pre-monsoon (May-June 2024) and post-monsoon (Nov-Jan 2025). This interim report presents work from the pre-monsoon sampling and analysis of data and results.