Assessment of Groundwater Quality with Special Reference to Fluoride Concentration in Parts of Kandukuruvagu Basin in Nalgonda District, Telangana State, India

Fluoride-enriched water has become a major public health issue in India. The present study tries to evaluate the geochemical mechanism of fluoride enrichment in groundwater of kandukuruvagu basin in nalgonda District, Telangana State, India. Total 50 groundwater samples were collected for the study spreading across the entire study area. The results of the analyzed parameters formed the attribute database for geographical information system (GIS) and Microsoft office excel analysis and final output maps. The fluoride concentration ranges from 0.44 to 5.4 mg/L (mean 2.85 mg/L), with 59 % of the samples containing fluoride concentrations that exceed the World Health Organization (WHO) drinking water guideline value of 1.5 mg/L and 81 % samples exceeding the Bureau of Indian Standards (BIS) guidelines of 1 mg/L. Presence of fluoride bearing minerals in the host rock, the chemical properties like decomposition, dissociation and dissolution and their interaction with water is considered to be the main cause for fluoride in groundwater. Chemical weathering under arid to semi-arid conditions with relatively high alkalinity favours high concentration of fluoride in groundwater. Dental and skeletal fluorosis are prevalent in the study area which can be related to the usage of high fluoride groundwater for drinking. The suggested remedial measures to reduce fluoride pollution in groundwater include dilution by blending, artificial recharge, efficient irrigation practices and well construction.