Re-evaluating hydrochemical data from aquifers occurring in the rio claro city region, sÃo paulo state, Brazil

Abstract

Groundwater use increases every year in different sectors of the society, therefore, hydrochemical studies of aquifers and their relations with the anthropic environment are crucial. With an area of approximately 1,880 km2 comprising Rio Claro city and near districts, the study assembles a series of groundwater data from previous assessments and aims using available tools to reach a new approach regarding the data in the literature. The database comprised a total of 41 groundwater samples from regional wells exploiting the aquifer systems Rio Claro, Serra Geral, Guarani, and Tubarão, as well the Passa Dois aquiclude, all them situated in the Paraná basin geological context. Locally, the study area is associated with a sedimentary deposit of sandstones, shales, limestones and unconsolidated sediments. The data of the chemical analyses of major ions and main physical parameters of the water samples were re-evaluated through The Geochemist's Workbench 11.0.5 software and compared with three water potability standards: São Paulo State Environmental Agency, Brazil Health Ministry, and World Health Organization. Moreover, a series of hydrochemical diagrams and graphs (Piper, Schoeller, Stiff and Durov) were generated in order to classify the samples and evaluate their local behavior in comparison with the data of other aquifers in São Paulo State.