The paper gives hygienic characteristics of water supplying conditions in the oil-producing areas of the Republic of Tatarstan. A long-term intensive oil-field development, without taking into account its environmental influence, is shown to have resulted in the pollution of water resources and broken the conditions of water consumption by the population. There has been a considerable increase in the total mineralization (1.8-2.3 g/l) of rivers, the levels of chlorides (300-1200 mg/l) and sulfates (300-1800 mg/l), and the salinity of springs. The implementation of nature-conserving and sanitary-and-hygienic measures have stabilized and improved the qualitative composition of water sources used for drinking water supply in the oil-producing areas of the Republic of Tatarstan, leading to a marked trend for improving water supplying conditions and accordingly the quality of the population's life.