[Significance of underground waters for population water supply of oil- producing regions in the Republic of Tatarstan].

The paper provides the hygienic characteristics of the underground waters used for water supply of the population of oil-producing regions in the Republic of Tatarstan (RT). The most common indicators of poor-quality drinking water of centralized water-supply systems from underground sources are shown to be its high mineralization, hardness, and higher than normal hygiene levels of chlorides, sulfates, and iron. The primary reason for drinking water quality deterioration is a high (as high as 70%) wear of water mains. It is noted that industrially based sanitary-and-hygienic and nature-conservative measures to improve water supply conditions for the population are being implemented under the financial backing of OAO "Tatneft" in the oil-producing regions. Considerable development-and-survey work is under way to detect and approve underground water reserves; underground reserves of fresh water have been today industrially introduced for the water supply of the towns of Zainsk, Bugulma, Nurlat, and the industrial community of Urussu. More than 400 springs and sources have been constructed, by meeting all the sanitary-and-hygienic requirements.