The maintenance and development of the centralized household underground water supply system in the closed administrative-territorial entity Seversk, Tomsk Region, when the aquifers are inadequately protected and there is a hydrological association of individual aquifers with polluted surface waters require a hygienic estimation based on the use of a risk methodology, including that considering the regional feature of sanitary situation establishment. No risk realization has been ascertained for damage to critical organs and systems in pediatric and adult populations under the population influence of the chemical substances available in drinking water.