Hygiene of water and water supply. Drinking water quality

Hygiene of water, maintaining its quality at the proper level, is one of the most important tasks facing humanity. On how we cope with it, the life and health of the inhabitants of the Earth directly depends.

Water is the most common natural compound on our planet. Its specific heat varies nonlinearly: it reaches its lowest values at a temperature of 37 ° C. Water conducts electricity poorly. With the presence of dissolved salts in it, its electrical conductivity rises.

Features of the chemical composition

The molecules of the H ₂ O compound are sufficiently stable, which, in combination with special electrical characteristics, turns it into a universal solvent. That is why there are always a lot of chemical compounds in the water. The main part of the elements presented in the table of DI Mendeleyev is present in natural water. More and more active industrial activity of mankind leads to the emergence of a number of inorganic and organic compounds in it, because of which it is necessary to constantly monitor their quantity. As a result, water hygiene is becoming particularly relevant. The structure of the molecule (of the triatomic it is the smallest) explains many features of such an important compound as H ₂ O.

Amount of water in organisms

In the adult body, the volume of water is approximately 65-70% of its total mass. Its content is very high in food. In fish, for example, it reaches 85%, in meat - 79%, in fruits and vegetable oils it reaches 78-97%. Speaking about the total amount of water in organisms, it should be noted that they account for only half of its volume in comparison with that containing all the rivers of the Earth. A person is able to live without food for 65-70 days, but without water it can last only a few days. If its loss occurs, equal to 6-8% of the total body weight, a strong dehydration of the body begins. If its loss is 10-20% of the total body weight, there is a threat to life.

Indicators of water quality assessment

Water hygiene is assessed by certain indicators. According to the accepted norms, it should be harmless in its chemical composition and in epidemic proportions. Water hygiene is assessed by the following indicators: the presence in it of pathogens of parasitic diseases and pathogenic microorganisms; Concentration in water of chemicals, including radioactive; A change in properties called organoleptic (the presence of color, taste, odor, the appearance of turbidity, film or foam).

Water quality and morbidity

If the quality of drinking water is unsatisfactory, the health of those who use it, significantly worsens. According to WHO, every year in developing countries, several hundred thousand people die as a result of its unacceptable properties. The spread of intestinal infections (500 million cases a year, of which developing countries account for about 80% of the diseases) are attributed either to poor quality of drinking water, or to its shortage.

It should be noted that not only when ingestion of inferior water can cause various diseases, but also when using unwashed vegetables that have been grown in fields subjected to irrigation. Scientists found that the number of people not provided with benign water is 1100 million. It is no accident that WHO put forward a 10-year program aimed at improving water supply, as a global social and medical task for all states.

Sources of water supply

It is very important that in the sources used for water supply, for medicinal purposes, for recreation and sports, for bathing, and also in water bodies located within the boundaries of settlements, the quality of water corresponds to sanitary standards. If the natural composition of the water is unsatisfactory or if the source is characterized by significant anthropogenic pollution, even the most modern cleaning methods can not guarantee satisfactory quality.

Water sources are estimated for various hygienic characteristics, the most important of which are: water quality, its exposure to man-made (social) and natural factors, as well as the sanitary reliability of the source, that is, its resistance to the effects of anthropogenic and natural factors. If we talk about centralized drinking water supply, the sanitary reliability of its source is determined by its ability to maintain water quality at a high level, as well as the sufficiency of the flow necessary for the operation of the operated and projected water supply system.

Sources of water are both underground and atmospheric waters, as well as open water bodies. If there is a choice, preference is usually given to the underground, it is best to use deep-lying ones. Waterproof ground layers reliably protect them from surface contamination. If these waters can not be used or if they are not available, the water supply is based on other sources. In this case, the priority is the following (from lower to higher):

• Atmospheric water;
• Rivers that have dams (with regulated drainage);
• Lakes;
• Rivers that do not have a dam (with unregulated drainage);
• Groundwater aquifers surface horizons;
• Springs and keys (the best option).

Assessment of drinking water quality

Among the main documents on the basis of which the analysis of water is carried out, it is necessary to note the following:

• GOST 2761-84.
• SanPiN 2.1.4.1074-01.
• SanPiN 2.1.4.1175-02.
• SanPiN 2.1.4.1110-02.

In brief, we will talk about each of them.

GOST 2761-84

The first document from our list, GOST 2761-84, establishes the principles that need to be guided by selecting water sources (surface or underground) for centralized water supply. Also in this document principles of rationing of bacteriological, chemical, organoleptic and physical indicators of water are specified. In addition, it describes the ways of processing it depending on the quality of a particular source. The analysis of water should show the absence of such properties and composition that can not be brought to an acceptable level by existing treatment methods.

Chemical substances contained in water should not give it an off-tasted and smell, cause the presence of foam, change the color of water. In other words, they should not degrade its consumer qualities and organoleptic properties. It is the task of quality control that is pursued by this GOST. The sampling of water must be carried out carefully in order to avoid distortion of the indicators. In accordance with GOST, water should not have a negative effect on the sanitary regime (the processes of self-purification) of water bodies and on the human body.

The normalization of the content of radioactive and chemical substances in the environment, including water, is based on the principle of threshold. This means that within the limits of allowable concentrations (doses), the presence of certain substances is harmless (safe) for the organism. It is necessary to take into account possible long-term consequences.

SanPiN 2.1.4.1074-01

Today, the main among the normative acts that establish the rules of water hygiene in our country is the second of the above documents, SanPiN 2.1.4.1074-01. The norms of the composition of drinking water indicated in it, it should be noted, take into account substances whose content is undesirable in it and can be tolerated only within certain limits. Ingredients that must be present in water are not included in this document. It must be said that the hygienic standards contained in it, in their entirety, represent not the standard of quality of water used for drinking, but a federal data bank. It is addressed when it becomes necessary to create a water quality control program for a certain (specific) water pipe. To regulate the composition, the principle of a regional approach is applied.

SanPiN 2.1.4.1175-02

Another important document, according to which hygiene of water and water supply is assessed, is SanPiN 2.1.4.1175-02. According to him, in its properties and composition, it must comply with certain standards, which are given in the table of this document. Much attention is paid in SanPiNe to those properties of water that are organoleptic. The document outlines the following chemical indicators: dry residue, hydrogen index, permanganate oxidability, nitrate, chloride and sulfate content. In addition, there is an indication of the permissible content of certain chemicals at a certain level, not exceeding the MPC (the maximum allowable concentration for hygiene standards). In accordance with these indicators, water samples are evaluated. For each source, the list of substances to be monitored must be installed separately. This should be based on local conditions, as well as the results obtained during the sanitary examination.

SanPiN 2.1.4.1116-02

SanPiN 2.1.4.1116-02 is designed to regulate the quality of potable water packaged in a container. The sanitary norms and rules presented in it do not apply to dining rooms, medical-dining rooms and medicinal mineral waters. The main purpose of these standards is to provide residents of the country with high-quality prepackaged water, the content of biogenic elements in which is optimal. It is important to note that when it is produced, the use of chlorine preparations is unacceptable. Ozonization, as well as various physical methods of treatment (for example, treatment with UV radiation) are the most acceptable methods of decontamination. The study of water intended for sale is the responsibility of each manufacturer.

Will there be enough water for mankind?

The norms for water used for drinking are constantly being reviewed in connection with the deterioration of the ecology, observed as a result of human activity, and also due to the growth of scientific knowledge. To meet these changes, the equipment and technologies used for water purification are being improved. The task of man, each of us, is to use it for our own good, without destroying the water ecosystem.

It should be remembered that the connection with the formula H2O is one of the main riches on our planet. It is difficult to imagine what would become of her if fresh water disappeared or her hygiene was not carried out. Drinking water is vital for man. It should be drunk a day in an amount of about 1.7 liters. For cooking, washing and other needs, every day we need 20 times more of it each. The threat of the disappearance of vital drinking water is currently being preserved. All living things suffer from water pollution. It becomes harmful to the health of organisms. It is necessary not to allow catastrophic pollution of natural water, reduction of its volumes on our planet.