Article courtesy of Dinesh Kallungal | June 25, 2015 | The New Indian Express | Shared as educational material
KOCHI: The drinking water supply to lakhs of Kochiites from the Periyar is likely to be affected if the heavy discharge of water from Bhoothathankettu barrage and Peringalkuthu dam which triggers a colour change in the river and makes the water muddier continues in the coming days, coupled with heavy rain in the catchment areas.
Though the water has got muddier and the turbidity downstream as well as upstream has been rising over the last few days following heavy discharge of water into the river, the supply of potable water to Kochi has not been affected so far. However, if the rain continues in the coming days, the supply may not be normal as the authorities will have to scale down the production as more time will have to be spent for treating the water, said Babu Thomas, superintending engineer, Kerala Water Authority, Kochi.
Speaking to Express, Anil, assistant engineer at pumping station, Aluva, said the turbidity level in the river has not reached an alarming rate.
The maximum level was only 40 ntu (nephelometric turbidity units) on Monday and it dipped to 25 ntu on Tuesday.
However, the level of turbidity in drinking water is being brought down to the prescribed limit of 0.8 ntu by adding treatment chemicals in the water supply system as part of improving the quality of water, he said.
Besides, the officials have been monitoring the level of turbidity in river water and alum and lime are being added to the water based on the level of turbidity in order to bring the water quality level within acceptable limits, he added.
Apart from the sudden discharge of water from the Bhoothathankettu barrage and Peringalkuthu reservoir, if the authorities engage in the removal of silt at the Kallarkutty and Bhoothathankettu dams in the coming days, it would result in the discolouration of the Periyar, the officials said. Meanwhile, the Kerala State Pollution Control Board is all set to open its second water quality monitoring station at Eroor along the Periyar following reports of the presence of highly toxic substances in the river water.