This paper presents the hydro-geological and hydro-chemical study of fractured aquifers that form the Serra Geral Aquifer System (SASG) associated with acid volcanic rocks. The study area comprises part of the city of Carlos Barbosa, located in the northeast region of Rio Grande do Sul State. The study was developed based on the inventory and registration of existing wells in the region, the survey and interpretation of geological and hydro-geological data, in addition to the collection and analysis of samples from wells that are in operation and used by the CORSAN water supply company. The results highlighted that most wells have depth up to 150 meters with flow rates average ranging from 5 to 20 m³ h-1, located in areas with medium and high density of fractures, which have preferential orientation to the northwest. As for hydro-chemistry, water circulating through these aquifers is the calcic or magnesium bicarbonate type, predominantly mixed and calcic bicarbonate waters, with minor variations in the concentration of ions and their ionic reasons. These hydro-chemical characteristics are typical of waters that circulate within structures and acid volcanic rocks indicate a low residence, with concentrations varying with water input depths.
hydro-geochemical characterization; Serra Geral aquifer system; groundwater