EN
Lake and ground water in the catchment areas of Piaseczno (mesotrophic), Łukie (eutrophic) and Moszne (dystrophic) lakes located in the Polesie Region (South-Eastern Poland) were studied in 1996–1997. Ground water were sampled from the wells installed on the lake shores (several metres from the shoreline) and lake water from the littoral zone next to the wells. EC, pH, concentration of Ca, Mg, K, Na, N-NH₄, N-NO₃, P-PO₄ as well as DOC and its fractions were determined. Mineralisation of ground water was higher and pH lower than that of the littoral lake water. The amount of fulvic acids both in lake and ground water was higher than the amount of humic acids.