CHENNAI: Untreated sewage and industrial effluents from Karnataka continues to pollute the Thenpennai (South Pennar) river, causing ecological damage and health hazards in downstream Tamil Nadu, the Water Resources department (WRD) informed the Southern Bench of the National Green Tribunal (NGT) on Tuesday.
In a suo motu case registered based on media reports, the NGT had directed Tamil Nadu to submit a report on pollution levels in the river, which WRD secretary J Jayakanthan submitted before the Southern Bench. The report said polluted discharge from Bengaluru’s Bellandur, Agara, and Varthur lakes flows downstream through Sokkarasanapalli in Krishnagiri and accumulates in the Kelavarapalli reservoir.
“The water entering Tamil Nadu was blackish with a sewage-like odour. Foam and foul smell were observed at Kelavarapalli dam with no sign of aquatic life,” the report stated.
The 432-km-long river, with 320 km flowing through Tamil Nadu, supports irrigation, drinking water and industries across five districts. The pollution has affected farming on 9,000 acres and impacted water supply to Hosur and surrounding areas, the report said. It blamed Karnataka for failing to upgrade sewage treatment plants and regulate polluting industries. “Unless industrial discharge is curbed, Tamil Nadu cannot undertake effective bioremediation,” the WRD said in its report.
A central negotiation committee has conducted nine meetings and site visits, observing black, foamy, odorous water in tanks and river stretches across both states. Despite repeated requests, Karnataka is yet to act on recommendations. When the matter came up for hearing, Karnataka’s counsel said 12 new STPs would be ready by December and 10 more were planned, but did not specify interim measures.
D Shanmuganathan, standing counsel for Tamil Nadu government, said chief secretary had written to Karnataka counterpart way back in April 2023, but no action had been taken. In 2019, Karnataka said it was building STPs with a cumulative capacity of 630 MLD. “The slow progress is impacting downstream Tamil Nadu.” The case has been adjourned to August 21.