Summary. The paper provides comparative characteristics of water quality in the assessment of a risk for intestinal infections in drinking water use. It has shown that of the greatest predictive value is direct detection of potentially pathogenic microorganisms, as well as the integral indicator determined by glucose fermentation, such as glucose-positive coliform bacteria. Estimation of the per cent of nonstandard samples of water before its entering the distribution network and in the latter, including glucose-positive Escherichia coli GPEC, is recommended. The samples containing GPEC in a quantity of more than 2 CFU/100 ml should be singly taken into account.