Result of analysis by Central Pollution Control Board for the years 2013-17

More than half of the country’s critically-polluted waterbodies, in terms of chemical pollution, are found in Karnataka, with its capital itself accounting for 17 lakes and tanks with the highest chemical pollution.

From Bellandur to Hebbal, 17 lakes and tanks in the city have been categorised as critically-polluted with Chemical Oxygen Demand (COD) levels, which indicate chemical pollution, topping 250 microgrammes per litre, shows data that was submitted to the Lok Sabha recently.

The Minister of Environment, Forest and Climate Change, Mahesh Sharma, provided a list of 38 rivers and 48 lakes, tanks and ponds in the country that have been categorised as critically-polluted in his response recently to a question on chemical contamination by two MPs from Bengal.

The analysis was done by Central Pollution Control Board (CPCB), in association with the State Pollution Control Boards, for the years 2013-17. Over 253 rivers and 259 waterbodies are being monitored under the National Water Quality Monitoring Programme.

Water bodies

Karnataka tops the list in critically-polluted water bodies, followed by Telangana with 12 and Kerala with 6. “While lakes in and around Bengaluru are polluted, it is hard to believe that lakes in other States are not as polluted or worse off. This is perhaps because other State Pollution Control Boards do not monitor or give reliable data,” said an official of the Karnataka State Pollution Control Board, which is monitoring 120 lakes and tanks in the State.

Even according to KSPCB’s monitoring, all 51 lakes in the city or immediate outskirts are in the ‘D’ or ‘E’ category — that is, ‘unsatisfactory water’ that can be used only for wildlife propagation or industrial cooling purposes.

Bhima most polluted

Interestingly, in the list of 38 rivers, only Bhima from the State finds mention.

“This is surprising as Arkavathy and Vrishabhavathy carry the sewage and industrial effluents from industries in and around Bengaluru,” said Sharachchandra Lele, researcher from Ashoka Trust for Research in Ecology and the Environment (ATREE).

Research from the organisation had shown that Peenya’s effluents had seen COD in Vrishabhavathy exceed 800 mg/l while Arkavathy often exceeded 500 mg/l. Even KSPCB’s monitoring data shows that Arkavathy, followed by Bhadra river, is in the lowest category of water quality.

However, for Panchappa Kalaburagi, president of the Bhima River Farmers' Committee, the listing of the 86-km-long river which passes through Vijayapura, Kalaburagi and Yadgir districts, the extreme chemical pollution in the river is not a surprise. “Sugar factories and cement factories along the stretch dump effluents directly into the river, while rampant sand mining in both Karnataka and Maharashtra has resulted in the disappearance of sand, which can naturally filter pollutants,” he said, adding: “Where is the river now? It is only stagnant pools of effluents.”