Rivers in Chennai and Salem have been identified as “priority stretches” by the Central Pollution Control Board (CPCB) based on water quality data, as per a response by Kirti Vardhan Singh, Minister of State for Environment, Forest and Climate Change, in response to a question posed by M. Thambidurai, Rajya Sabha MP, on February 6.
According to CPCB, Tamil Nadu has 10 severely polluted river stretches and have been categorised under Priority I to V. Of these, the Adyar and Cooum in Chennai, and Thirumanimuthar and Vasishta rivers near Salem are Priority I.
The Cooum river stretch from Avadi to Sathya Nagar is the most contaminated, with a biochemical oxygen demand of 345 mg/L, far exceeding the permissible limit of 3 mg/L for bathing waters. These rivers, already facing ecological degradation, are under severe threat from untreated industrial effluents, untreated sewage, and waste dumping, making them unfit for both human use and aquatic life.
In response to these pollution hotspots, the Tamil Nadu government has devised comprehensive action plans aimed at rejuvenating the affected river stretches, Mr. Singh said in the response. These plans prioritise improving municipal sewage management, controlling industrial effluents, enhancing waste management practices, and safeguarding river catchment areas. Several ecological initiatives, such as the establishment of biodiversity parks, removal of encroachments along riverbanks, and floodplain zone management, have also been proposed, he added.
A joint inspection by the Ministry of Environment and the Tamil Nadu Pollution Control Board revealed widespread non-compliance with wastewater treatment standards in several textile and dyeing units across the state. Following inspections in 2022, 25 non-complying units were issued closure orders by the TNPCB, and regular checks are now enforced to ensure proper wastewater treatment, the response said.
