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The quality of the groundwater in the study area was evaluated through various water quality indexes for drinking and irrigation purposes. To evaluate the water quality index, 186 groundwater samples were sampled during 2 different seasons, likely pre-monsoon (PRM) and post-monsoon (POM). The collected samples were measured for physical-chemical parameters like pH, EC, TDS, Na, K, Ca, Mg, Cl, HCO3, PO4, SO4, NO3 and H4SiO4. The research findings indicated that groundwater of the study area is approaching an alarming stage of its suitability for drinking purpose because a major percentage (i. e. 56%: PRM, 46%: POM) of samples are within poor category. Thus, the proper management strategy for water resources must be developed and a preventive management practice to address this issue must be implemented. Various water quality parameters such as electrical conductivity (EC), pH, salinity hazard, sodium hazard and permeability indexes (PI) were considered for irrigation water quality evaluation and it is inferred that the groundwater of the study area is suitable for irrigation. The PRM and POM samples with higher Na + and Cl concentrations were identified. The primary source of groundwater contamination is anthropogenic factors like domestic, agriculture effluents and mining activities. However, the groundwater of these regions is also greatly influenced by geogenic factors like weathering, rock-water interaction and precipitation which results in groundwater water level fluctuation. The research findings suggest the groundwater quality of this region is approaching an alarming stage for drinking purposes. Thus, developing a management strategy for drinking water sources and implementing preventive management practices to address this issue becomes imperative.

Uranium (U) in groundwater is hazardous to human health, especially if it is present in drinking water. The semiarid regions of southern India chiefly depend on groundwater for drinking purposes. In this regard, a comprehensive sampling strategy was adopted to collect groundwater representing different lithologies of the region. The samples were collected in two different seasons and analysed for major and minor ions along with total U in the groundwater. Two samples during pre monsoon (PRM) and seven samples during post monsoon (POM) had U > 30 μgL−1, which is above the World Health Organization's provisional guideline value. The high concentration of U (188 μgL−1) was observed in the alluvial formation though a few samples showed the release of U near the pink granite (39 μgL−1) and the concentration was low in the lateritic formation (10 μgL−1). The uranyl carbonato complexes UO2(CO3)22− and UO2(CO3)34− were associated with high pH which facilitated the transport of U into groundwater especially during POM. U3O8 is the major form observed in groundwater compared to either UO2 or UO3 in the both seasons. The uranium oxides were observed to be more prevalent at the neutral pH. Though U concentration increases with pH, it is mainly governed by the redox conditions. The principal component analysis (PCA) analysis also suggested redox conditions in groundwater to be the major process facilitating the U release mechanism regardless of the season. The POM season has an additional source of U in groundwater due to the application of nitrogenous fertilizers in the alluvium region. Furthermore, redox mobilization factor was predominantly observed near the coastal region and in the agricultural regions. The process of infiltration of the fertilizer-induced U was enhanced by the agricultural runoff into the surface water bodies in the region. Health risk assessment was also carried out by determining annual effective dose rate, cancer mortality risk, lifetime average daily dose and hazard quotient to assess the portability of groundwater in the study area. Artificial recharge technique and reducing the usage of chemical based fertilizers for irrigation are suggested as sustainable plans to safeguard the vulnerable water resource in this region.