Summary:

Determined were the volume of river sediment captured in a water reservoir at Wilcza Wola on the Łęg river. The water reservoir with 3.86 mln m3 capacity was put into operation in 1989. Silting measurements were performed after 10, 13 and 14 years of operation. Computed reservoir silting ratio were respectively: 13.08%, 15.79% and 16.20%. Samples of bottom deposits were collected to determine their physical and chemical properties. Determining of heavy metal concentrations may provide a basis for the sediment quality assessment and their potential applications in the environment after extracting from the reservoir bottom. Contents of harmful substances assessed in the sediments were compared with limit values permissible by the decrees of the Minister of Natural Environment Protection, Natural Resources and Forestry guidelines and criteria suggested in the foreign literature of the subject. The sediments from the water reservoir at Wilcza Wola are characterized by a low content of heavy metals. According to the Decree on soil quality standards [Joural of Laws, No.65, item 1359] none of the values established for the studied elements were exceeded. According to German guidelines threshold values of heavy metal concentrations in bottom deposits are between twice and thrice higher than those obtained in the studies on silt deposits from the Wilcza Wola reservoir. Limit values of heavy metal concentrations in variously polluted soils, according to IUNG [Kabata-Pendias 1993], revealed that Cd and Ni values are on the 1st level of pollution. The first level of pollution points to elevated heavy metal concentrations, but the soil material may be used for all field crops, excluding crops for production of food with especially low contents of harmful elements and substances. The deposits from the reservoir at Wilcza Wola are characterized by low content of harmful substances, particularly heavy metals. The sediments extracted from the bottom of the reservoir will not pose any hazard for either water or soil environment.