Everyone certainly wondered if the tap water, the popular “tap” is really suitable for drinking. Theoretically suitable. Municipal waterworks, after all, they treat it, filter it, etc. However, as we know the theory sometimes does not go hand in hand with practice …
1. General messages
Water commonly referred to as “drinking by law” is called “water intended for human consumption. It must meet strict bacteriological and physico-chemical requirements. All processes to which water is subjected on the road – the recipient is used to obtain and maintain its quality. Tap water is created from the so-called “raw water”. “Raw water consists of 2/3 of ground water and 1/3 of subsurface water. This is primarily about lakes, dams and coastal water filtration. “Raw water is created in waterworks. At least 50 chemicals are used to make it. In drinking water, certain limited amounts of other additives are allowed
Requirements for water are specified in the Regulation of the Minister of Health of November 19, 2002 on the requirements for the quality of water intended for human consumption (Journal of Laws No. 203, item 1718). It should be emphasized here that the requirements of the Polish regulation are at least as detailed and strict as the EU requirements. Some indicators must meet even stricter standards than is expected in other EU countries.
The microbiological (sanitary) and physicochemical indicators determine the quality of water.
Microbiological indicators speak about sanitary security. Many of the pathogenic bacteria are growing in the gut, hence the possibility of contaminating water with faeces. Bacteria whose presence is determined in standard tests are indicator organisms. This means that they are not pathogenic bacteria, but only bacteria that occur naturally in the human and animal gut. If their presence is confirmed, it may be evidence of water contamination by faeces. Then, detailed research is conducted on the source of water pollution and the presence of pathogenic bacteria. Three groups of faecal bacteria are routinely tested. Each species has a different biology. Faecal coliforms, including Escherichia coli, survive briefly in water – their appearance may be associated with fresh contamination.
Fecal streptococcus live longer in water – their presence testifies to old (lasting) pollution.
Clostridia bacteria produce spores, so they survive in water for the longest time. Due to their biology, they can only occur in surface water (and only in the surface water samples are tested). If they are in the water, this proves the possibility of contamination.
Because water contamination with fecal bacteria creates a real danger for recipients, sanitary requirements are very strict. In a standard sample of this type, 100 ml of drinking water can not contain a single bacterial cell.
In addition to faecal bacteria testing, the total number of bacteria is also determined. This allows you to assess the possible risk of bacteria other than fecal origin. The methods of conducting research, i.e. the cultivation of bacteria for a suitable time at a suitable temperature, refer to the biology of known pathogenic bacteria. As a result, certain amounts of bacteria are allowed in the water sample – they are harmless bacteria that accompany people in everyday life.
Physicochemical indicators speak primarily about the content of chemicals in water. It is not only about substances harmful to health (metals, especially lead, cadmium, mercury, chromium, organic substances or THM THM), but also substances that may affect the installation (iron, fluoride, pH, hardness).
Water that comes from well-known and working shots has a stable and stable composition. In practice, pollution of such water with particularly dangerous substances does not happen. They do not occur in water or in the environment. There would have to be external serious pollution (factory failure, intentional contamination). Therefore, in standard water tests, the presence of selected components is checked, including those whose presence is evidence of contamination. If their standards are exceeded, detailed tests are carried out.
Under certain circumstances, however, violations of iron, taste and smell may occur.
Iron and manganese
If the water is to come from a deep water well, the study of this water very often shows an elevated content of iron and manganese, while the remaining indicators are within the norm.
This is a natural phenomenon for underground groundwater and is associated with the type of substrate on which these waters occur. Removal of iron and manganese is very simple (carried out on appropriate filters) and effective.
On the other hand, periodic ironing of water, which manifests itself with a yellow color of water and a metallic taste and smell, does not prove deterioration of water quality from the intake. It is associated with the rinsing of steel pipes, especially in old installations. Steel pipes overgrow for years of use – they form a sediment consisting of a biological membrane and iron compounds. This reduces their diameter and the quality of the water that flows through them may deteriorate. Periodic rinsing, eluting compounds from pipes, causes temporary inconvenience for the user – rinsing impurities must flow through his taps. However, long-term benefits (better water quality, proper pressure in pipes) are clear.
Some users complain about the strong smell of chlorine in the water. Chlorine disinfects water and prevents so-called secondary pollution. Secondary pollution can occur in old pipes. Through the formation of sediment, the conditions for bacterial growth arise in them. They can reach the taps of recipients together with the water that raises them. Therefore, the water leaving the treatment station as clean must be protected against the loss of its properties by re-chlorination
2. Water cleaning
More and more often we can meet a place where drinking water will not endanger our health or life. However, all living organisms need clean water. We need people responsible for water management to not only provide water for flats, but also to ensure that this water has the right quality to ensure that we can drink clean water. The quality of water is assessed on the basis of its physical properties (color, temperature and taste), biological (here the most important thing is that it does not contain bacteria) and chemical (degree of hardness and content of mineral compounds). For example, water from limestone deposits with a high content of magnesium oxides is usually very hard. Bathing in such water, it is extremely difficult to soak, and it can not be used in the textile industry.
Different composition and properties of water coming from natural sources and unequal requirements as to their quality on the part of users cause that many methods of treatment are applied. Drinking water must meet stricter conditions than those used for irrigating fields. There are strict regulations defining the quality of water and the manner of its use, taking into account criteria such as color, turbidity, reaction, hardness, concentration of chemical elements and the amount of bacteria and microorganisms. Removal of harmful components from the water, as well as the change of its composition and properties by means of physical and chemical processes, are dealt with by water treatment stations. Groundwater and surface waters differ in their degree of pollution and therefore their treatment methods are not identical. In the first case, purification takes place in two stages.
In the first one, metals are removed by aerating water (iron and manganese ions are first oxidized, which in turn precipitate in the form of hydroxides and the remaining sediments are filtered.) The second (and generally the last stage) is disinfection, i.e. removing unnecessary and dangerous water The desired effect is achieved by chlorinating the water, that is by acting on it with chlorine gas, less common methods of combating microorganisms are ozone, ultraviolet radiation and the use of ultrasounds. Treatment of surface waters, more exposed to pollution, begins from the removal of suspended solids in a process called coagulation, consisting in the assembly of particles, the precipitate settling on the bottom of the settler is removed and its remains are separated by filtration of water through sand or – in case of larger impurities – by activated carbon.
Additional processes are used to achieve the right water quality. From the sanitary point of view, the most important is purification of drinking water and economic needs. Taste and smell can be changed in the process of desalination and degassing (venting) of water. It is quite difficult to remove specific smells and flavors from the water, which are caused by the abundant presence of microorganisms or small aquatic organisms. If the usual methods of drinking water treatment do not reduce the intensity of smells to such limits that users do not feel, you have to resort to special methods, for example chlorine oxidation or activated charcoal.
One of the most important methods of water treatment is clarification. Its aim is to remove mechanical impurities that are found in lakes and rivers. Mechanical impurities can be divided into the following groups
1. light thick suspensions (plant debris, leaves, algae, etc.) floating on the surface of the water, which is removed by means of bars
2. smaller suspensions removed by means of metal sieves
3. fine suspensions (microsuspensions) removed by means of microsites and in settling tanks
The mentioned methods clarify water, but do not remove bacteria and microorganisms from it. A necessary step in improving the quality of water is its disinfection (decontamination), which usually takes place after the previous filtration
3. Poles and drinking water
Poles drink too little water, and their knowledge about it is unsatisfactory. 41% of Poles regularly drink tap water, although it often does not meet drinking water requirements (NIK audit). Most of the respondents have problems with “tap water, but hardly anyone chooses to put a filter in order to solve them … Poles still drink the water most straight from the tap (41% does it regularly) and prepare most of the meals on it. “Even people (29%) who describe it as unhealthy and 38% of those who assess its taste as average drink regularly. More often, people aged 25-34 (48%) drink tap water; people over 65 (46%); people with primary and lower secondary education (52%) and those living in cities up to 100,000 (47%) or in the countryside (46%). She is avoided by people with higher education (53%) and those who live in the largest Polish cities (53%). The popularity of “tap water may be worrying, given the results of the NIK audit carried out in March 2002. This inspection showed that in 2/3 of cities the quality of tap water supplied to the population and water drawn from generally available public wells did not correspond to drinking water requirements.
Poles do not drink the recommended 6-7 glasses of water a day. Compared to 1999, when we drank 3.2 glasses a day, water consumption increased slightly (currently 4 glasses a day), but it is still not enough.
In the last 5 years, the consumption of bottled water has almost doubled, which indicates that Poles are looking for an alternative to tap water. However, they rarely decide to filter water, despite the fact that it is the cheapest method to improve its quality. * Only 7% of respondents declared regular or frequent use of filtered water for the preparation of cold drinks; more often they filter water for tea (10% of Poles do it regularly or often). The water is especially filtered by people with BA and higher education and from larger cities. This is due, among other things, to the availability of knowledge about healthy eating. Higher education affects consumer awareness, who wants to consume safe food and drink safe, clean water. Such people also more often and more willingly search for information on tap water treatment techniques. The decision to filter water for tea or coffee also influences how we assess its hardness. Definitely more often such water is filtered by people assessing their “tap water as hard.
Water, in a household, is not only for consumption. It is also used for cleaning, washing and washing. Poles most often use tap water for this purpose – generally, you do not have to filter it. It is worth knowing, however, that the use of softened water (and this can be obtained by filtering “tap water with home appliances) helps to avoid limescale embedded in appliances such as kettle, iron, curling iron, humidifier, washing machine or dishwasher. The use of filtered water can therefore prolong the life of these devices.
We assimilate water not only in pure form or in the form of beverages. It is also a component of various foods and dishes. In general, we use unfiltered tap water (83%) for the soup. Only 8% of people use filtered water for this purpose (mainly people with higher education) and 8% use bottled water or from Oligocene intakes. When preparing compotes and preparations, we also use filtered (6%) or bottled water (8%). However, 76% of people use regular tap water for this purpose.
Our attitude towards “tap water” changes when we prepare a meal for babies or small children.
Only 24% of people decide to use unfiltered tap water for this purpose. 57% avoid using tap water for this purpose. It must be assumed that this is due to a lack of trust in this type of water.
Limited knowledge of Poles about drinking water leads to numerous wrong judgments. Among them, we can find, among others the belief that it is not enough to filter water to make it drinkable – you have to boil it. Mineral water can be used for everything (including cooking).
Water taken from Oligocene intakes can be stored “on stock.
Water will always be available, its resources are inexhaustible.
To avoid limescale deposits in the iron, humidifier, only distilled water must be used.
“Not long ago, nutritionists recommended frequent drinking 100% of fruit juices. In the face of the growing problem of overweight and obesity, which affects more than half of Polish society, now people are encouraged to resort to clean water and low-calorie drinks, such as vegetable juices – says Dr. Lucjan Szponar. “Initiatives that encourage Poles to drink water more often are very much needed, especially because it is the best quenching drink and completely devoid of calories – he adds.
As shown, tap water should meet all requirements of cleanliness and be as safe as possible for humans. Is it and should it be taken care of by its purity? If I’m tasting someone, I do not mind, the law is supposed to be clean, but as shown by stumbling, it happens often. We have to take into account that even if the number of components negatively affecting our health is low in tap water, we drink it every day which may result in an increase in the concentration of dangerous compounds in our body.
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