Evaluating the sustainability of mineral water consumption using multi‐scale hydrogeophysics in Caxambu, Brazil

Abstract A better understanding of the near‐surface aquifer system of the Caxambu Water Park, located in the Minas Gerais State, Brazil, has been achieved. The study aimed to identify groundwater reservoirs and flow patterns and contribute to the hydrogeological conceptual model using a multi‐scale geophysical approach. Audiomagnetotellurics and electrical resistivity tomography methods were employed, in addition to surface and structural geology. Structural contrasts at different depths were identified, allowing the characterization of the key geometric parameters of the aquifer system. The obtained geophysical models satisfactorily mapped the resistivity of the alluvial deposits, the crystalline basement and the base of the Caxambu Hill at depths of up to 200 m. The results revealed a distinctive brecciated groundwater reservoir containing conductive mineralized water beneath the mineral water springs of the Caxambu Water Park and the adjacent hill. Furthermore, it was possible to identify a deformation domain of the Caxambu Shear Zone that transports mineral water from depths greater than 190 m to the near‐surface fractured and porous aquifers. The presence of a conductor in the alluvial sedimentary layer indicates that the porous aquifer connects with the fractured aquifer and contains mineralized water. According to previous chemical and isotopic studies in the Caxambu Water Park, the original construction method of the water fountains prevents the external contamination. These results contribute to the sustainable exploitation of the resource and provide essential information for the effective management of regional water systems, ensuring the preservation of the therapeutic characteristics of the Caxambu water.