Water quality poor in Ramnagaram: report

More than 90% of drinking water samples collected from houses in a cluster of villages in Ramnagaram district near Bengaluru are unfit for human consumption, according to a new study.

When researchers tested the source of water, they found that in 80% of cases the water sources were also contaminated. Moreover, the poor quality remains unchanged throughout the year, suggesting contamination of the groundwater.

The samples were screened for Escherichia coli (E.coil) bacteria that can trigger diarrhoea. Its presence also indicates faecal and sewage contamination.

Water was collected from eight villages in Byramangala panchayat area of Ramnagaram district. The samples were tested for microbial contamination as well as chemical impurities.

Only 7% of household drinking water samples complied with the WHO permissible limits, said the study published in the November 10 issue of the journal 'Current Science'.

The three-member team that conducted the study comprised researchers from Trans-Disciplinary University, Bengaluru and Manipal University.

While 20% of drinking water samples at source complied with the WHO standards for E.coli (no risk category), the percentage of samples complying with the household level was only 7%, indicating further contamination of water at the household level.

Around 58% of samples were found to be under low risk and 35% were under moderate risk category for diarrhoea, based on the E.coli count.

All of these villages are located within 5 km of Vrishabhavathi river, which is known to be contaminated with sewage and industrial wastes mainly from Bengaluru and Bidadi industrial areas.

Samples analysed

To check how the water quality varies with season, the scientists also analysed 45 drinking water samples collected from public taps from each of the eight villages in five different months between December 2014 and September 2015.

"Only 17.78% of samples at all five-time points complied with the WHO permissible limits, while 29% of the samples put people under high to very high risk for diarrhoea," the researchers reported.

Besides the E.coli, the samples were also screened for total dissolved solids, calcium, magnesium, alkalinity and hardness. The levels of all of these materials were beyond acceptable limits. The nitrate levels too were consistently high and beyond the WHO permissible levels.

"Alarming levels of microbial and chemical contamination of drinking water press
for appropriate remedial measures to reduce health threats, particularly among vulnerable population," the scientists said.

DH News Service