Daijiworld Media Network - New Delhi
New Delhi, Aug 7: The Central Pollution Control Board (CPCB) has identified 311 polluted river stretches (PRS) across 279 rivers in India, the Lok Sabha was informed on Thursday. These stretches were marked based on Bio-Chemical Oxygen Demand (BOD) levels, a key indicator of organic pollution in water bodies.
In a written reply to questions raised by MPs Bhausaheb Rajaram Wakchaure and Bharti Pardhi, Minister of Jal Shakti C.R. Paatil said that while river pollution remains a concern, there has been a reduction in the number of polluted stretches — down from 351 in 2018 to 311 in 2022 across 30 States and Union Territories.
According to the minister, 106 stretches have been delisted, and 74 stretches showed improvement in water quality between 2018 and 2022.
The CPCB has been monitoring river pollution since 2009, and has published four reports based on assessments conducted in 2009, 2015, 2018, and 2022. The identification process is based on long-term monitoring and data analysis of river water quality.
Minister Paatil also detailed the mechanisms used to monitor water pollution, which include both manual sampling under the National Water Quality Monitoring Programme (NWMP) and Real-Time Water Quality Monitoring Stations (RTWQMS).
Currently, the CPCB monitors 4,736 water quality locations, including 2,155 locations across 645 rivers nationwide. These stations form the backbone of efforts to assess river pollution and guide the development of corrective action plans.
To ensure accuracy and transparency in data collection:
• Water samples are analysed using the 2017 Guidelines for Water Quality Monitoring, issued by the Ministry of Environment, Forest and Climate Change.
• Testing is conducted in NABL-accredited laboratories.
• The CPCB conducts annual audits of monitoring sites via its regional offices.
• State Pollution Control Boards participate in proficiency testing through Analytical Quality Control (AQC) exercises.
• All water quality data is made publicly available on the CPCB website.
The information comes amid increasing national focus on cleaning India's rivers and improving the quality of water in key aquatic ecosystems.