Análise da qualidade da água e avaliação de impactos ambientais em um trecho urbano do Rio Vacacaí Mirim, Bairro Camobi, Santa Maria, RS

Abstract

The various uses of water make this natural resource essential for living beings. Therefore, it is essential to guarantee its quality and quantity. The main goal of this work was to carry out water monitoring, analyzing the physical-chemical and biological parameters, in the urban area under study of the Vacacaí-Mirim river, located in the Camobi neighborhood, in the municipality of Santa Maria, Rio Grande do Sul. Sampling was carried out every two weeks, at three different points, from May to July 2022. The parameters turbidity, pH, color, total solids, total fixed solids, total volatile solids, electrical conductivity, BOD, hardness, dissolved oxygen, total and thermotolerant coliforms were analyzed in the laboratory. These parameters show values within the quality standard, for less demanding uses, established by Regulations CONAMA 357/2005, CONAMA 430/2011 and ordinance 888/2021. However, it was possible to notice that the sampling point 3 is the section with the worst qualitative conditions of the river, in the parameters color (118.1 uC), turbidity (24 NTU), dissolved oxygen (7.24 mg/L), electrical conductivity (213.40 uS/cm at 25ºC), total solids (273.7 mg/L), fixed solids (65.33 mg CaCO3/L) and BOD (22 mg/L). However, only the color, electrical conductivity and BOD parameters exceeded the values established by legislation, probably due to the discharge of sewage in the river close to the third sampling point. All sampling points had the presence of thermotolerant coliforms, which we can conclude that the region is affected by lack of basic sanitation.