Assessment of surface and groundwater quality in the Ctalamochita river basin, Argentina: Hydrogeochemical characteristics and exploratory data analysis.

Abstract

Surface and groundwater are important resources for the drinking water supply and the development of agricultural and livestock activities in the Córdoba province, Argentina. The objective of this study was to assess the physicochemical and microbiological quality of surface (n = 14) and groundwater (n = 17) sites in the middle-lower basin of the Ctalamochita river (Córdoba, Argentina) for human and animal consumption. A total of 18 physicochemical and five microbiological parameters were evaluated to determine the hydrogeological characteristics of both water resources and their suitability for human and animal consumption using the Water Quality Index (WQI). The results indicated that Na⁺ and HCO₃^‒ were the dominant cation and anion, respectively, both in surface water and groundwater. Physicochemical and microbiological parameters values were compared with limits recommended by national and international guidelines. The WQI showed that groundwater samples exhibited poor quality compared to surface waters for human consumption, due to high concentrations of major ions and the presence of total coliforms and Pseudomonas aeruginosa. Meanwhile, the WQI for animal consumption indicated that both surface and groundwater samples were suitable for this purpose. Piper diagram showed that most of the surface and groundwater samples were classified as Na⁺-Cl^‒-HCO₃^‒ and Na⁺-HCO₃^‒, respectively, showing the hydrogeochemical difference between the two water resources. Gibbs diagram indicates the processes of rock-water interaction and evaporation control the chemical composition of surface and groundwater sources. The findings of this study would enable the development of a proactive plan aimed at preserving safe and sustainable water resources in the middle-lower basin of the Ctalamochita river. This could be achieved through the implementation of preventive strategies and the introduction of innovative policies.