Suitability of Fluoride-Contaminated Groundwater for Various Purposes in a Part of Vaniyar River Basin, Dharmapuri District, Tamil Nadu

Abstract

Groundwater has become a vital source of water for domestic and agricultural activities all over the world. The objective of this study is to investigate the fluoride-rich groundwater for assessing its suitability for drinking and irrigational purposes in Vaniyar River basin, Dharmapuri district, Tamil Nadu. About 650 groundwater samples were collected and analysed. Na–Cl and Ca–Mg–Cl–SO4 are the major hydrochemical types of groundwater present in this area. The concentrations of major ions are within the permissible limits of Bureau of Indian Standards in most of the area. Fluoride concentration exceeded the maximum permissible limit of the drinking water standards of 1.5 mg/l in 446 samples. The use of this groundwater for drinking purpose has caused dental and skeletal fluorosis to many of the residents of the area. The major source for fluoride in groundwater is due to the leaching of fluoride-bearing minerals in the rocks of this area. Fluoride ions from biotite and hornblende minerals leach into the groundwater and contribute to high fluoride concentration in this region. The groundwater of this area is characterised by high salinity and low sodium. Even though groundwater in the area is suitable for irrigation, it is not suitable for domestic purpose in most of the region.