LAUSR

The study was conducted on the Słup reservoir and the Nysa Szalona river (Poland). The material was benthic water and sediments. The aim of the study was to evaluate accumulation of Ca, Mg, Na and K in the sediments. The assessment of studied elements accumulation was based on calculations of the cumulation factor in the sediment. On this basis, an attempt was made to assess the possible impact of the compounds deposited in the sediment on the organisms living in the reservoir and on the change in the composition of water which constitutes the basis for drinking water. It was found that the studied sediments are rich in Ca, Mg and K compounds but relatively poor in sodium compounds. The level of the studied elements in the sediment and water in the annual cycle does not show strong changes and in the relatively stable conditions existing in the reservoir it does not pose a threat to organisms living there. Moreover, it does not adversely affect the composition of water which is obtained for water supply purposes.