The dependence of the chemical composition of near-bottom waters and bottom sediments on the character of the immediate catchment basin and the morphology of the bottom of the lake basin is shown. Differentiation of the content of such microelements as Ba, Sr, Pb, Mn, and Cr was observed in the sediments. The content levels of lead and chromium were higher than the accepted toxic levels for macrophytes. The different chemical composition of the supersediment waters at a depth of 7.5 m on the side of arable land and forest indicates increased ground feeding of the lake from this section of the catchment basin.