Figure 2

Box-and-whisker plots of physico-chemical parameters (i.e. pH, specific conductivity (SC), oxidation–reduction potential (ORP) and dissolved oxygen (DO)) in pit lake surface water samples. The height of the box shows the interquartile range, which contains 50% of the values, while the horizontal line inside the box shows the median value and the red cross denotes the mean value. The whiskers are lines that extend from the box to the highest and lowest values excluding outliers (o) and extremes (*). In this sense, outliers represent those values being between 1.5 and 3 times larger than the length of the box from its upper or lower border while extreme are those greater than 3 times such value.