Foamy water from Kelavarapalli reservoir choking farmlands along Thenpennai river.
| Photo Credit: File photo
The southern bench of the National Green Tribunal (NGT) has directed the Karnataka government to submit an action plan within a month to control the discharge of untreated sewage and industrial effluents into the Thenpennai river. This is pending the completion of new sewage treatment plants (STPs) scheduled for the end of December 2025.
The directive came during a hearing on July 15, based on a suo motu case initiated by the bench based on news reports. The bench expressed serious concern over the river’s condition, particularly in the stretch flowing from Karnataka into Tamil Nadu, where foaming, blackened water, and foul odour have been reported.
In its order, the bench, comprising Justice Pushpa Sathyanarayana and expert member Satyagopal Korlapati, noted that untreated domestic sewage and industrial waste from Bengaluru, especially from Bellandur and Varathur lakes, is being discharged into the river, causing significant pollution downstream in Tamil Nadu.
Karnataka’s report revealed that 531 industries are located in the river’s catchment area. Of these, 11 were found to be non-compliant with environmental rules. While plans for 10 new STPs with a capacity of 313 MLD are underway, only four have received administrative approval, and none are yet operational.
Tamil Nadu officials reported heavy pollution of the Thenpennai River as it enters the State. Frothing, hyacinth growth and contamination of irrigation tanks near the Kelavarapalli dam in Hosur were cited. Tamil Nadu has urged Karnataka to prevent untreated waste from entering the river and improve pollution monitoring.
A central Negotiation Committee, formed to address interstate water disputes inspected polluted sites in June 2024 and confirmed the presence of black, foamy water and a strong odour. the team also found untreated sewage from residential areas was polluting tanks and lakes around Bengaluru.
The bench stressed the urgency of interim pollution control measures, especially with the monsoon approaching Tamil Nadu, and warned that waiting until STPs are completed would worsen the situation. Karnataka’s legal counsel sought a month’s time to respond.
The bench has scheduled the next hearing for August 21, 2025, and instructed the Karnataka government to file a report outlining short-term measures to curb pollution of the Thenpennai river.
Published – July 19, 2025 01:06 am IST
