Geometry and water quality of the unconfined aquifer near the Piracicaba river, Ipatinga/MG, Brazil

Abstract

Groundwater is the main source of drinking water for the city of Ipatinga/MG, Brazil. However, there is a lack of study about hydrogeology in the region, as well as indications of quality alterations of water resources. The goal is to understand the hydrogeology surrounding the COPASA's Water Treatment Plant and the Piracicaba river areas, where the main water supply wells are located. Maps of potentiometric surface, isobaths and isopachs, hydrogeological cross-section, aquifer pumping tests, and physicochemical analysis interpretations were performed. Results indicate the aquifer is unconfined, with high transmissivity and hydraulic conductivity values, which explain the high values of discharge in the wells. The Piracicaba river can be considered as influent, with its water flow converging to the aquifer. Groundwater shows chemical parameters at low levels, according to Brazilian drinking-water quality guidelines, with local presence of aluminum, iron, and manganese, requiring only conventional treatment processes before distribution.