Study on water and bottom sediment quality of the Kozłowa Góra drinking water reservoir in Silesian province was carried out. Heavy metal concentrations in water body and bottom sediment of the reservoir were determined. Water quality assessment was perform by comparing concentration of heavy metals to standards for I class water quality. The degree of sediment contamination was carried out by calculating cumulation coefficient: sediment/water and sediment/ geochemical background. Present water and sediment contamination in the reservoir was compared with the state 20 years ago, which was a period of intensive metallurgical industry development in this region. At the same time, heavy metals speciation in sediment for those of high rate accumulation: Zn, Pb and Cd was determined. The results of heavy metal speciation in sediment provided a basis to secondary water pollution assessment, due to migration of these metals to water body.