NEW DELHI — A latest assessment report by the Central Pollution Control Board (CPCB) shows that while the overall number of polluted river stretches in India has seen a slight dip, the stretch of the Yamuna river in Delhi remains among the most critically contaminated, with pollution levels up to 27 times higher than permitted.
The CPCB reviewed water quality data from 2022 and 2023, covering 2,116 locations across 32 states and Union Territories, to produce its latest report.
National Trends and Delhi’s Stagnation
The CPCB identifies a polluted river stretch based on its pollution load, specifically when the Biochemical Oxygen Demand (BOD) concentration continuously exceeds the acceptable limit of 3 \text{ mg/L} (the ideal value for outdoor bathing).
The total number of polluted river stretches across India has seen a consistent decline over the years, dropping from 351 in 2018 to 311 in 2022, and further to 296 in the current assessment.
Most Polluted Category (Priority I) Stretches where BOD exceeds 30 \text{ mg/L} classified as Priority 1 and requiring urgent remediation—have also reduced, from 46 in the 2022 report to 37 this year.
However, the report notes that the water quality status of the Yamuna in Delhi has shown no shift in its position despite the national trend of improvement in other stretches.
Yamuna BOD Levels Up to 27 Times the Limit
The stretch of the Yamuna river in Delhi, specifically from Palla to Asgarpur village, continues to be one of the most polluted in the country, categorized under Priority 1.
The maximum BOD value observed in the Delhi stretch between 2022 and 2023 was 83 \text{ mg/L}. This figure is approximately 27 times higher than the permitted level of 3 \text{ mg/L}.
The CPCB monitored water quality at seven locations in Delhi, including Palla, ISBT Bridge, and Okhla, and reported that the water quality criteria were not met at any of the monitoring locations.
Other river stretches classified as Priority 1 include the Amlakhadi river and Sabarmati in Gujarat, and the Chambal river stretch in Madhya Pradesh.