Qualidade da água de abastecimento da Comunidade dos Pimentas, Lavras–MG

Abstract

Water quality is a factor of major importance for the society, given that physical, chemical and microbiological traits should be kept within certain limits. In this work, we aimed at evaluating the physical, chemical and microbiological aspects of underground wells and springs, and relate the water quality with soil use and occupation, as well as characterizing the soil regarding its acidity, at the Comunidade dos Pimentas, in the municipality of Lavras, MG, Brazil. The residents of this community use water from natural sources, which are never subjected to laboratory tests to evaluate the quality for use. The samples were collected in the second semester of 2013 and first semester of 2014, at several points. The variables evaluated were turbidity, pH, acidity, hardness, iron, color, dissolved solids and total and thermal-tolerant coliforms for the wells, and variables pH, BOD, nitrate, phosphate, turbidity, total solids, dissolved oxygen, temperature and total and thermal-tolerant coliforms for the lagoon and its vicinity. For the water from the wells, microbiological contamination was the main polluting factor, while physical and chemical variables satisfy the VMP of decree No. 2914/2011. The factors contributing to fecal contamination may be associated with the closeness of household sepitc tanks, in addition to the reuse of residues from swine culture in agriculture. Soil acidity analysis resulted in a high acidity, which interfered with the acidification of the water. The Water Quality Index (WQI), based on the data collected, presented values above the rates established by the CONAMA Resolution 357/2011, and is not suitable for the development of primary contact recreational activities, for the irrigation of vegetables, fruit plants and parks, gardens, sports and leisure fields, with the possibility of use for human consumption after treatment. Thus, we conclude that the values are not within the standards established by COPAM/CERH 01/2008, with the exception of section 2, which showed satisfactory values. Therefore, a frequent monitoring of the water quality from the wells and surface water of the lagoon and its downstream is necessary. In addition, this study aids the community on preventive actions.