The remains of human activities may be seen in several places of the landscape in positive or negative form. Probably the most common phenomenon that fundamentally impacts the country is mining activity. The environmental problems caused by mining have attracted a great deal of research attention and led to development of numerous sediment heavy metal contamination assessment methods, including the index method, the dynamic method, the synthesis methods in chemistry, ecology and toxicology, etc. This research was undertaken in order to determine and analyze selected heavy metals present in sediment samples collected from different sampling localities inside and around water reservoir Ruzin, Slovakia. Reservoir and its inflows are located in the vicinity of region with historical Cu, Fe, Ag, Au-deposit, which was exploited from the 14th century to 1990 and currently causing environmental burden. For the determination of sediments quality different methods (XRD and XRF analysis) have been used. Based on the obtained data of analysis, potential ecological risk indices were used to study the pollution status of heavy metals in sediments and assess their potential ecological risk to environment. The calculated potential ecological risk indicates the level of water environment pollution by heavy metals in the sampling localities in the studied area.