The fluoride content of the groundwater in these regions varied from 1.5 to 12.4 milligram per litre against the permitted limit of 1.5mg/l. Due to consuming water with high fluoride content, a large part of the population was impacted by dental, skeletal, non-skeletal fluorosis.

The TN government had come up with the project in 2010 to give potable drinking water to 17 town panchayats, three municipalities, 7,639 rural habitations in the two districts by tapping the surface water from the Cauvery.

The short and irregular supply of water, thus, pushed many local bodies to mix the high fluoride content groundwater with the Hogenakkal water to fulfil the demand. The CAG report presented in the TN assembly recently highlighted that an inadequate supply of potable water defeated the scheme's aim.

K N Nehru, Minister for municipal administration and water supply, carried out inspections last week and urged officials to take appropriate steps to execute the scheme efficiently.

Shiv Das Meena, Additional principal secretary of municipal administration and water supply, told the media that they increased the water supply from 128 million litre per day (MLD) to 140-145 MLD to fix the inadequate supply.

Meena said they have made 70 squads to carry field inspections to recognise the issues in the water supply under the project. Each squad would involve engineers from the Tamil Nadu water supply and drainage board (TWAD) and officials from the local organisations. District collectors and authorities have been urged to communicate to the public about the scheduled days of the supply of potable water and build awareness to use only the protected water for cooking and drinking.

A senior official in TWAD said the squads have been ordered to conduct field inspections and present a comprehensive report on the difficulties in the distribution system. The official said that they began the inspection three days ago.