<span class="fontstyle0">Groundwater consumption is increasing in Brazil. However, the disordered urban expansion of Brazilian cities has provoked significant impacts on the water sources that supply these localities. The analysis of the water quality used for human consumption from public artesian wells is very important. Chemical analyses of the underground water were performed from march to July 2018. Nitrate, ammonia and pH were analyzed and compared with data obtained from the last 15 years. It was possible to observe a high acidity in all studied locations. 33% of the water samples presented high levels of nitrate and ammonia. The temporal analysis showed a deterioration of water quality in the studied. These results indicated that the water quality is decreasing, and this degradation process has been going for a long time.</span><br /><br />