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Kerala rivers polluted by faecal contamination: PCB study

Coliform count in most of the Kerala rivers and ground water is far above the permissible limits. Photo: Leju Kamal

Coliform count in most of the Kerala rivers and ground water is far above the permissible limits. Photo: Leju Kamal  

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Air heavy with RSPM, says report

Coliform count in most of the Kerala rivers and ground water is far above the permissible limits whereas air in most cities was thick with Respirable Suspended Particulate Matter (RSPM), warned the Kerala State Pollution Control Board.

The findings are part of the Water and Air Quality Directory-2013, to be released by the Kerala State Pollution Control Board (KSPCB) on June 5, World Environment Day.

The Ambient Air Quality was assessed between 2009 and 2013 after collecting data from 30 stations under the National Ambient Air Quality Monitoring Programme and the State Ambient Air Quality Monitoring Programme.

Though the annual “average sulphur dioxide and Oxides of Nitrogen (NOX) were never found exceeding the limit values during the assessment period, the RSPM values exceeded the limit value many times.

The RSPM values exceed the limit at seven stations during 2012 and in nine stations during 2013. In Ernakulam, the values exceeded the limit at five stations during 2012 and 2013,” the report said.

The Board came out with water data after monitoring water samples from 128 stations covering 42 rivers, seven rivulets/tributaries and six reservoirs. Three fresh water lakes, eight estuarine lakes, three canals, two ponds and 34 stations in groundwater too were covered under the mammoth monitoring programme.

High levels of coliform in drinking water indicate “contamination from surface or hallow sub-surface sources such as soil, septic or cesspool leakage, animal feedlot runoff and treatment failures.” Ideally, water supplied to the consumer should be free of coliform bacteria. However, “practically this may not be always attainable,” the report conceded.

Water quality of Kerala rivers mostly conforms to the category A, which is defined as “drinking water source without conventional treatment but after disinfection under the Best Designated Use classification of Central Pollution Control Board.”

Water samples collected from Moonnattumukku sampling station in Karamana River shocked researchers as faecal Coliform count was found to be 14,000 colonies per 100 ml water.

The Total Coliform in the water sample was 54,000 colonies.

Contaminated water brought to the stream by tidal action from Parvathyputhanar might be contributing to the high Total Coliform and Faecal Coliform count, researchers said.

The study indicated an increasing trend in Coliform count and the Biochemical Oxygen Demand (BOD) in the rivers across the State. The BOD, indicator of water pollution, is defined as the “amount of oxygen required by aerobic microorganisms to decompose the organic matter in water,” it warned.

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Printable version | Jul 20, 2018 1:08:31 AM | https://www.thehindu.com/news/national/kerala/kerala-rivers-polluted-by-faecal-contamination-pcb-study/article6083312.ece