Avaliação da potabilidade das águas subterrâneas do Sistema Aquífero Bauru provenientes de poços de soluções alternativas coletivas do município de Tupã - SP

Abstract

Water quality, as well as quantity, is of vital importance to all living organisms and the proper functioning of ecosystems, communities and economies. Groundwater is intensively used for a variety of purposes, such as human supplies, irrigation, industry and leisure. However, some activities developed by man have significantly compromised the quality of these waters. The objective of the present study was to analyze microbiological and physicochemical parameters of potable water abstraction in 25 wells registered as collective alternative solutions in the city of Tupã-SP, to evaluate the causes of contamination detected in the wells studied and to monitor representative wells for twelve months. Microbiological analyzes and physico-chemical analyzes of apparent color and ammonia were performed according to American Public Health Association (2012) and of turbidity, total hardness, total dissolved solids, iron, chloride, fluoride, nitrite and nitrate, according to physico-chemical methods of the Adolfo Lutz Institute (2008). Regarding the microbiological analyzes, 11 (44%) of the 25 raw water samples analyzed had total coliforms and 3 (12%) had E. coli. In the monitoring of the five selected wells, the microbiological analyzes showed contamination by total Coliforms in at least one of the samples of each well monitored in the period of 12 months and E. coli was identified in only one well evaluated in the period. The results of apparent color, turbidity, total dissolved solids, total hardness, iron, chlorides and fluorides of the 25 wells evaluated and the 5 wells monitored in the twelve month period showed that all analyzed samples presented values according to the current legislation. Analyzes of the nitrogen compounds showed that the ammonia and nitrite results of the 25 wells and later performed in the monitoring were in accordance with the standards established by the legislation. The nitrate concentrations of the 25 wells evaluated ranged from 1.9 to 23.2 mg /L-NO3-N. Of the 25 samples analyzed, 8 (32%) were in disagreement with the legislation in force because they presented concentration above the maximum allowed value. Regarding the results of the nitrate analysis of the 5 wells monitored, with the exception of well nº. 20 (Hotel) that showed variations in the concentrations, all results from the other wells monitored were in accordance with the legislation and did not show large variations between the months evaluation. This study showed the importance of microbiological and physicochemical analyzes of the groundwater of the city of Tupã-SP, knowledge of the causes of contamination and provides subsidy for the establishment of a correct management of water resources and, consequently, the reduction of related risks waterborne diseases, protection of consumer health and the environment.