The control at water supply on criteria of quantitative and qualitative adequacy--one the major sections of sanitary-and-epidemiologic supervision. To radical improvement of water supply of the population of the country, army and fleet are called to serve entered in action since July 1, 1997 Sanitary rules and norms 2.1.4.559-96 "Drinking water. The hygienic requirement to quality of water of centralized systems of drinking water supply. Quality surveillance". In the interest of increase of epidemiologic safety of drinking water in comparison with GOST 2874-82 specifications of microbiological parameters are severed and a parasitologic parameter is entered. The new document changes accepted early classification of chemical structure of water.