According to Kruskal]Wallis proof see Table 4 there are no statistical differences in the concentration of chromium, iron and cadmium among the different sampling zones, suggesting a uniform distribution of those heavy metals in sediments and a
similar precipitation behaviour Tipping et al., 1993; Droppo and Stone, 1994; Stone and Walling,Fig. 4. Variation of Cr and Pb contents in surface water and column water of the J. A. Alzate Reservoir. Lead and chromium show similar reduction in water concentration to iron and zinc.