CPCB report: Marginal dip in polluted river stretches across India, most in Maharashtra

Key Highlights:

• CPCB report indicates a marginal decrease in polluted river stretches in India, from 311 to 296.
• The assessment reviewed water quality data from 2022 and 2023 across 2,116 locations.
• Maharashtra has the highest number of polluted river stretches at 54.
• 37 river stretches are classified as Priority I, the most polluted category.
• Tamil Nadu, UP, and Uttarakhand have the highest number of Priority I stretches with five each.

Detailed Insights:

• The CPCB assessment identified polluted stretches based on Biochemical Oxygen Demand (BOD) levels exceeding 3 mg/L.
• Priority I stretches have BOD concentrations exceeding 30 mg/L, indicating the highest pollution levels.
• Notable polluted stretches include the Yamuna in Delhi, Sabarmati in Ahmedabad, and stretches of Tungabhadra in Karnataka.
• Rivers showing deteriorated water quality include Ganga in Bihar, Hasdeo in Chhattisgarh, and Cauvery in Karnataka.
• A polluted river stretch is defined as two or more polluted locations on a river in a continuous sequence.

Key Concepts Involved:

• Biochemical Oxygen Demand (BOD): The amount of oxygen required by microorganisms to decompose organic matter in water.
• Polluted River Stretch: A continuous segment of a river with two or more locations exceeding acceptable pollution levels.
• Central Pollution Control Board (CPCB): A statutory organisation responsible for monitoring and regulating pollution in India.