Central Pollution Control Body Says Cauvery Water Let By Karnataka Into Tamil Nadu Is Polluted

A new controversy has broken out between Karnataka and Tamil Nadu over Cauvery. However, this time the controversy is over the quality of water.

The Central Pollution Control Board (CPCB) has submitted a report to the Supreme Court that Cauvery water from Thenpennaiyar and Arkavathi flowing into Tamil Nadu is polluted. Times of India has reported that CPCB submitted its report to the apex court on Friday after Tamil Nadu filed a case in 2015 to stop Karnataka from letting untreated sewage and industrial effluents into these rivers. Tamil Nadu meets at least one-third of the drinking water needs of its population from the Cauvery water with 127 drinking water schemes being fed by the river.

CPCB tested waters from Cauvery as well as the two tributaries from September to December 2017. The board took water from Cauvery at Ajjibore, from Thenpennnaiyar at Chokkarasanapalli and from Arkavathi at Sangama.

“River Thenpennaiyar is polluted and comprehensive plan of action is required for restoration of its water quality. The Arkavathi and Cauvery rivers were found to be polluted due to higher count of faecal coliform, attributed to open defecation and requires vigilance from the concerned organisations in the state to prevent further pollution,” CPCB has said in its report, according to Times of India.

CPCB’s analysis of the samples showed that Arkavathi and Cauvery met the stipulated quality before Sangama and Ajjibore between September and November as far as the presence of organic pollution was concerned. Organic pollution is measured as biochemical oxygen demand. But the level exceeded limits in December. Bacterial pollution, through the presence of coliform and faecal coliform, was above prescribed limits in September and October in Arkavathi. In Cauvery and Thenpennaiyar, the samples didn’t meet the specifications all four months.

CPCB had identified the spots for drawing the samples after discussions with both states. Tamil Nadu insisted that Arkavathi, which joins Cauvery some 50 km from Bengaluru and passes through Mekedatu before entering Tamil Nadu, is one of the main sources of pollution, but Karnataka objected to the monitoring. Tamil Nadu contends that untreated sewage and industrial effluents are let into the river in and around Bengaluru. It argued that the river received untreated sewage and industrial effluents from Belandur Lake and Vardhur Lake in Karnataka.

Thenpennaiyar originates from Nandidurg Hills in Karnataka and enters Chokkarasanapalli village in Tamil Nadu, 25 km from Hosur, and passes through Krishnagiri, Dharmapuri, Tiruvannamalai, Villupuram and Cuddalore districts. Tamil Nadu officials allege that Karnataka is not taking adequate efforts to treat the sewage in and around Bengaluru properly.