Hydrogeochemical and isotopic studies of the Bauru Aquifer System in São Paulo State

Abstract

Groundwater use for public supply is present in 55% of the Brazilian cities. In São Paulo state 72% of the cities are total or partially supplied by groundwater, providing water to a population of about 5,5 million people. Understanding chemical composition is essential to evaluate the quality of the water, to establish the adequate uses of water resources and to identify the causes for hydrochemical differences. The purpose of the present work is to characterize chemical and isotopic compositions of the aquifer units of the Bauru Aquifer System in the state of São Paulo. Previons works involving hydrogeochemical studies of groundwater of the Bauru Group have been performed. In the present study chemical and isotopic characterization of the aquifers will be executed separately for each aquifer unit. For this, wells with lithologic and casing/filter profiles will be selected for sampling, considering recently proposed lithostratigraphic subdivision based on subsurface data. The studies will be carried out mainly in the northern portion of the Bauru Group occurrence in the state of São Paulo, with groundwater sampling to occur in selected wells. Chemical and isotopic data collected from previous works will be added to those of the present study in order to develop an integrated hydrogeochemical model for the Bauru Aquifer System in the state of São Paulo. (AU)