Potabilidade da água disponível para consumo nos ambientes de ensino da Cidade de Cruz das Almas - Bahia

Abstract

Water is an essential element for life and careless management compromises its quality and endangers human health due to diseases. Current analysis assesses the drinkability of water available in schools in the municipality of Cruz das Almas BA Brazil, during the dry and rainy periods, with regard to its physical, chemical and microbiological parameters based on Ordinance 2914/2011 of the Ministry of Health and on the Resolution of CONAMA 357/2005 and 396/2008. The latter are a helpful subsidy for the health authorities of the municipality with regard to water quality in the school milieu. Twenty-five government-run school institutions participated in current study. Water was collected at four different sites: first tap of the water supply network or of the collective alternative supply (1st site); main reservoir (2nd site), kitchen water (3rd site) and the main water drinkers (4th site), coupled to information retrieval on the city´s main water supply source. The parameters for the evaluation of water quality comprised physical (color; turbidity), chemical (pH, free residual chlorine, dissolved oxygen, Biochemical Oxygen Demand) and microbiological (total coliforms, Escherichia coli, Enterococcus, Mesophylls, Psycrotrophic) parameters. Of the 25 participatory educational institutions of the study, 14 of these samples were from a water supply system, 9 a collective alternative solution and 2 involves the two forms of supply Considering the two evaluation periods, for total coliforms, there was contamination in about 65.31% of the samples. In 9 samples we verified the presence of E. coli. For microorganisms enterococcus Positive values were seen in 36.73% of the samples. In the dry period it was possible to visualize higher counts of mesophilic, when compared to the rainy season in 34.69% of the samples the counts were higher than ideal via legislation. Apparent variation for color of samples was not identified. For the turbidity and the pH only in institutions 2 values were irregular with the active legislation. The DO only two institutions in the dry period showed values improper while for BOD were in an ideal range. Although some samples lacked coliforms, other reported bacterial contamination, with the requirement of efficacious practices for improvement of quality. It was concluded that the risk to health in educational institutions in the city of Cruz das Almas (BA) can be solved with proper treatment of water, regular cleaning the tanks, proper maintenance of taps and filters.