In the submitted study the authors focused attention on the elaboration and testing of a new methodological procedure in the preparation of samples and detection of mutagenicity of drinking water. As compared with the hitherto used procedures, the volume of the sample was markedly reduced (from 50 - 200 l to 1 l), a higher yield of organic contaminants was proved when using columns filled with C18, the amount of acetone used for extraction was reduced and a higher sensitivity of bacterial indicator strains YG1041 and YG1042 for detection of the mutagenic potency of the organic extract of drinking waters was observed. This method can be recommended as a suitable indicator of the quality of drinking water in case emergencies or when testing the quality of unknown water sources.

        Key words: mutagenicity - drinking water - Ames test