Drinking water is first of all a health of the man. As " water is a life ", it is clear, that natural waters are inhabited by various living creatures, which are quite often dangerous to health of the man. In reality, the relentless statistics testifies that 80 % of all diseases in the world is connected to unsatisfactory quality of drinking water and breaking the sanitary - hygienic norms of water supply. The diseases are subdivided into five types: the diseases, caused by infected water (a typhus, cholera, dysentery); diseases of skin and mucous, arising at usage of the polluted water for washing (from trachoma to a leprosy); diseases, caused by mollusks, living in water; and at last, diseases, caused by insects, living and propagating in water - by carriers of an infection (malaria, yellow fever and so on).All in all, a half of mankind suffers from illnesses, connected to water - about 2 mlrd of people. It approximately meets that part of the population of globe, which to 1985 still lacked pure drinking water - 2,5mlrd of the people. The worst situation is in village, where only third of inhabitants has access to safe systems of water supply and only 13 % is supplied with the water drain. The greatest amount of water per person is given by drinking waterpipes of USA - 405 l per day (to 1975), but the part of this water is consumed by the industrial and economic enterprises, therefore the real consumption makes on the average 330 l, and in village district - 250l per day. The systems of water supply more than 90 % of the population of the country. The centralized water supply in the world covers, on average, the urban population with numeration of 1,1mlrd of people with the charge of 280 l per day and 0,8 mlrd of people is supplied with water from columns with the charge 110 l per day on a person. Other part of mankind consumes 50-60 l of water per day.

The standards for systems of water supply, determining safety and quality of drinking water, are created now, the special stations of preparation of water process natural water before its submission in distributive networks. The man has not come to such system at once. Millions of people have paid their lifes for this experience. For example, the history of a waterpipe of Paris knows many cases of mass diseases, connected to water. Cases of appearing of the cholera became more frequent in the beginning of the XIX century. And because of it J.Osman - mayor of Paris -who carried a radical re-planning of city, has charged the engineer E.Balgran to reconstruct system of urban water supply. Instead of the polluted river water, clean water from underground sources was provided. However even the modern systems of water supply give failures, that results the flares of diseases, connected to water. So, the country, most favorable on water supply in the world - USA has registered for the period within 1971- 1978 202 epidemics, which have captured up to 50 thousand of people. The American researchers consider, that no more than 10-30 % of similar flares is registered. Their reason is insufficient clearing and disinfecting of water.