Come summer, the Vijayawada Municipal Corporation (VMC) is flooded with complaints of drinking water emanating gammexane smell. Last year, there was a huge hue and cry over the water odour. To tide over the problem, the Corporation is contemplating changing the filter medium shortly.

The VMC will replace some portion of sand medium with bituminous coal at one of the filtration plants at K. L. Rao Head Water Works here. The project is estimated to cost Rs.21 lakh. The State government has sanctioned the requisite amount under ‘adverse seasonal conditions grant’ for the project to the city.

As it is a capital intensive work, the VMC is unable to replace all the four filtration plants at the Head Water Works. The VMC would require nearly Rs.1 crore if filter medium at all the plants are to be changed. The proposed technology will help in minimising the bad odour, say officials.

The water emanates gammexane smell due to algae present in the river and is a common thing during summer season. The algal blooms give off a few substances like cyanobacteria, Sinura and valvax that cause odour. They react with chlorine and emanate odour. The problem crops up as the canals are closed during summer. The scorching heat aggravates the problem. The filamentous algae grow in the river water if the day temperature exceeds 35ºC.

As the canals are also closed, the problem is aggravated. As long as the water flows, the scope for algae growth would be less.

There were apprehensions over quality of water as it emanated foul smell last year. A team from the Institute of Preventive Medicine (IPM) tested water at K. L. Rao Head Water Works here in April last.

The IPM team had conducted trial tests, which were encouraging. Subsequently, the VMC then treated the raw water with carbon to reduce the pollution levels.