Chemical investigation of water from a 21 ha lake with a maximum depth of 32 m formed in a former limestone quarry south of Kraków, Poland was carried out. The lake is meromictic, with maximum values of O2 in mixolimnion, and water homothermy noted in December. The important influence of the polluted Vistula River, flowing only in 600m distance that mainly infiltrates the quarry, resulted in high chloride content and conductivity value. Low chlorophyll a concentration and TSISD value show that the lake is oli-gotrophic, whereas the nutrient concentrations indicate slightly higher trophy.