Hydrogeochemical Evolution of Groundwater and Aquifer Studies in Nellikal Watershed Nalgonda District Telangana State India

Abstract

ABSTRACT People rely on groundwater for drinking purposes in many rural regions of India, newlinebelieving much cleaner resource than surface water. On the other hand, scarcity of rain in the many areas use of groundwater utilisation in the irrigation sector has increased. newlineCorrespondingly groundwater has been recognised and has become the world s most newlineextracted raw material. However, the interaction of host rock with water and various other anthropogenic activities leads to the development of secondary mineral phases. Therefore, understanding hydrogeochemical and aquifer studies in an intensive agricultural region i.e., Nellikal watershed, Nalgonda district, Telangana, has greater significance. newline Groundwater samples were collected in both seasons from a confined Nellikal watershed to evaluate groundwater quality assessment, seasonal variations in hydrogeochemical processes of dissolved ions. Some of the physicochemical parameters are analysed on-site during water sample collection. The samples were processed to analyse significant ions and trace elements using Ion chromatography and ICP-MS, respectively. The integration of WQI and GIS were used to evaluate the water quality based on recommended WHO permissible limits for various parameters. newline newline The major ions and their presence following the order, anions: HCO 3 - newlinegtSO 4 2- newline- newlinegt F newline and cations: Na newline+ newline+2 newlinegt Ca newline+2 newlinegt Mg newlinegt K newlinexi newline+ newlinegtCl newline- newlinegtNO 3 - newline respectively. Nitrate concentrations in 44% of the samples, 11% of samples found fluoride concentration is beyond the permissible limits for drinking purposes. The elevated nitrate concentration during pre- monsoon in groundwater might be due to agricultural practices in the region. newline Seasonal variations in groundwater quality revealed the extent of the spread of dissolved ions due to the input of rain during the monsoon through spatial distribution maps. Major ions such as Na newline+ newline+2 newline, Ca newline+ newline, K newline+2 newline, Mg newline- newline, F newline, Cl newline- newline, SO 4 2- newline, NO 3 - newline, HCO 3 newline are the controlling factors in natural groundwater.