Effects of the installation and operation of the Minas-Rio system mining com-plex on surface water quality

Abstract

Iron ore mining and beneficiation cause many environmental impacts. In the specific case of the mining site called Minas-Rio System, located at Conceição do Mato Dentro city, Minas Gerais, there is a lack of publications related to the influence of these activities in the superficial water quality of the region. At the same  time,  nearby  communities  are  concerned  about  the  implications  to  the

various uses of water. This article aimed to analyze the effect of the installation and operation of this mining complex on the superficial water quality from the surrounding hydrographic sub-basin, as well as the compliance of water quality parameters with environmental legal standards. It was analyzed monitoring data (monthly average) of the previous (2006, 2007) and posterior (2010 to 2016) periods to the installation and operation of the enterprise  to   the   following   parameters:  pH,  total  dissolved

solids, total suspended solids, turbidity, total iron, total manganese, BOD, total lead, total mercury and thermotolerant coliforms. The effect of the  location   (sub-basin  of   Passa   Sete   Creek,   of  Folheta

Riverside and of Santo Antônio River) and of the period of sampling (previous x posterior) were tested (Kruskal-Wallis and Mann-Whitney Tests). Relationship among the variables were tested through Spearman correlation. The conclusion is that the activities of installation and operation of the mining complex contributed to increase the levels of pH,   total   dissolved   solids,   total   suspended   solids,

turbidity, total iron and total manganese at the nearby water bodies (sub-basin of Passa Sete Creek). The parameters turbidity, total manganese, BOD and thermotolerant coliforms showed results above the legal limits, indicating that the water quality of the region is not suitable to several uses.