Untreated municipal effluents let into river
Picture used for representational purpose. (Photo: DC/File)
Chennai: The disposal of untreated and partially treated municipal and domestic waste into the Cauvery river has resulted in faecal contamination of its surface water, says the Tamil Nadu Pollution Control Board (TNPCB) in a report on inland water quality.
The quality of Cauvery river water is being monitored at 33 places along its course under two programmes, ‘Monitoring of Indian National Aquatic Resources’ (MINARS) and ‘Global Environmental Monitoring System’ (GEMS), to study how the various activities of the domestic and industrial sectors have an impact on pollution.
The overall analysis of data reveals that the faecal contamination of the surface water of the river is a common phenomenon due to the unhygienic anthropogenic activities and disposal of either untreated or partially treated municipal waste into the river systems directly or indirectly, says the report.
Out of the 33 places where water quality was tested, samples taken from Thirumanimuthar, Vasista and Sarabanga tributaries do not even meet the water quality criteria, Designated Best Use (DBU) class and this was due to disposal of municipal and domestic waste into the river systems directly at that particular sampling point.
At 25 of those locations, the water could at best be used for ‘outdoor bathing’. In five places, the river could be a drinking water source only after conventional treatment followed by disinfection, the report, which was part of the latest annual report of the TNPCB for 2012-13, tabled in the Assembly recently, said.
The water quality in the Thamiraparani river was not better than the Cauvery river. The biochemical oxygen demand (BOD) level, monitored at 12 stations, varied from two to 16 milligrams per litre as against the norm of 3 mg/litre. The level of pH value varied from 6.82 to 7.74, against the prescribed norm of 6.5 to 8.5.
The water from the river could at best be used for outdoor bathing except at Authoor and Srivaikuntam where BOD values were found to be high, the report revealed.
( Source : dc )
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