Save waterUseful Information - Water Supply

Rational management of water resources and water savings, as well as the need to cultivate a new water management culture, are vital in order safeguard the needs of modern society and our ecosystems.

Research conducted by prestigious international organisations has ranked Greece high in the list of countries with unwarranted water consumption and unreasonable degradation of ecosystems. The way in which we manage critical sectors such as crops, planning, fisheries, use of fossil fuels is anything but ‘green’, meaning that every year many hectares of ‘living space’ per resident are ‘sacrificed’.

Consumption of massive quantities of water to irrigate water-thirsty crops and the dramatic decline in reserves because of climate change, among other things are major ‘concerns’ for modern societies. However, in order to adopt a comprehensive, uniform policy to manage and protect water resources it’s essential to provide citizens with information and raise their awareness, and also to get them involved in taking decisions and implementing them.

Water savings at home could be as high as 50% if only we adopted some of the practical tips below.

Tips for rational use – saving water at home

  • Turn off taps when not in use, as while brushing teeth, shaving, soaping your hands/face or the dishes. By letting the tap run for five minutes, water wastage can reach up to 20 litres. For one million people, that means wasting 20,000 m3 of water a day!
  • Flushing the toiler accounts for 1/3 of all water used in the home. Replace old cisterns with new, double flow ones, or fix the floater.
  • Showers/bathing use up around 1/5 of all water used at home. Prefer a quick shower with moderate water pressure instead of filling your bathtub.
  • Use your washing machine and dishwasher when relatively full and choose eco programs.
  • Don’t neglect any leaks in the house’s plumbing. Immediately repair leaky taps, cisterns or plumbing.
  • Make sure everyone in the family knows where the main water supply stopcock is in the event of leaks or flooding.

Use the suggestions below to change your everyday kitchen habits.

  • Reduce the household utensils that require washing (use one glass for drinking water per day and appropriately sized cooking utensils).
  • Keep cold water in bottles in the fridge instead of letting the tap run.
  • Recycle suitable water from household uses, such from washing fruit and vegetables, for watering your plants.
  • Do not use running water to defrost food; defrost gradually by moving to the fridge and then to room temperature.

Tips for rational use – saving water outdoors

  • Wash your car with a bucket rather than with a hosepipe, as this reduces water wastage.
  • Clean the open spaces of our house like balconies & terraces by sweeping/mopping and not with a hosepipe.
  • Avoid washing your balconies, the pavement and your car during a drought or when there are water supply problems.
  • Do not overwater your garden. Water early in the morning or in the evening, as this reduces evaporation losses. Set the automatic watering system so that all water can be used.
  • Choose plants suitable for the climatic conditions of your area. Avoid planting grass as it requires excessive watering.

Frost protectionUseful Information - Water Supply

Tips for avoiding problems due to frost.

  • Check private water networks for leaks and damage or lack of insulation. Thoroughly check water meters (counters), outdoor taps (on balconies), solar water heaters, outdoor gas burners and outdoor piping.
  • Have qualified craftsmen restore or install insulations at vulnerable points of the external network.
  • Make sure that the internal water supply switches (valves) function properly.
  • Keep leaves and debris out of gutters on balconies and terraces.
  • If the house is to stay shut during the winter, isolate or empty the solar water heater network and the central water supply of your home. Make sure the installer/maintainer has put antifreeze in the solar water heater.

My tap water is turbid or white. Is there a problem or is it just air?

Water with bubbles has trapped air in it and appears turbid. Another cause of water discolouration is the build-up of limescale deposits. Healthy drinking water contains dissolved natural salts that add taste and nutritional value to the water. Dissolved salts existing in natural waters undergo sedimentation and pass through to tap water, giving it a white, milky colour. Such problems in the appearance of water can result from maintenance work carried out on the distribution network and do not in any way pose a risk to consumer health.

You can determine whether the water discolouration is due to trapped air or limescale deposits by performing the following simple test.

Fill a glass with tap water and let it settle. If the water contains trapped air, in approximately 10 minutes it will clear up and you will notice the air bubbles moving upwards until the water becomes completely transparent. If the water contains limescale deposits, it will need approximately one hour to become transparent and the limescale deposits will sink to the bottom of the glass. In other words, the water will start to become transparent from the top to the bottom.

In each of the above two cases, there should be no water discolouration after three hours, when the flow of the water through the pipes is restored to normal levels. If the problem persists, please contact us for more information.

My water seems to have some colour, what should I do?

In order to determine whether the water discolouration is due to the network or your house’s piping, compare your tap water to that of a neighbouring house. If the problem is found only in your tap, then it is likely that there is a problem with your house’s piping. However, if the problem arises from the network, then the water from the neighbouring house’s tap will have the same discolouration. In such case, contact us for more information.

How "Hard" is the water in our city?

Hardness represents the concentration of dissolved calcium and magnesium salts, and depends on the rocks the water has passed through. The term ‘hardness’ is used to define water that does not foam well when used for washing with soap, and forms limescale on the inner surfaces of domestic appliances. High hardness values are not harmful to one’s health. On the contrary, a correlation has been found between high hardness levels and a reduction in cardiovascular diseases.

There are no specifications regarding the hardness value of drinking water in the health regulation.

The hardness of water is measured in mg CaCO3/l, in German and in French degrees. The following factors can be used to convert from one unit of measurement to another:

1 French degree = 0.56 German degrees

1 German degree = 1.79 French degrees

1 French degree = 10 mg CaCO3/l

1 German degree = 17.9 mg CaCO3/l


Classification of water depending on the level of hardness

VERY SOFT0 – 7,160 – 40 – 71,6
SOFT7,16 – 14,324 – 871,6 – 143,2
SEMI-HARD14,32 – 21,488 – 12143,2 – 214,8
SEMI-HARD21,48 – 32,2212 – 18214,8 – 322,2
HARD32,22 – 53,7018 – 30322,2 – 537,0
VERY HARD> 53,70> 30> 537,0


Consult the below table for information on the hardness value of the water in your area. Based on the below values, you can adjust your washing machine to the hardness of the water in your area. Washing machine manufacturers often require this adjustment in order to ensure the proper operation of the appliance.


Hardness values by area

AreaHardness Values (German degrees)
EVOSMOS12 – 17
METEORA12 – 13
NEAPOLI12 – 17
SYKIES13 – 15
PEFKA14 – 15
ΚΕΝΤΡΟ16 – 17
NEA KRINI13 – 14
ARETSOU14 – 15
NTEPO14 – 16
DELFON14 – 16
KIFISIA12 – 13


Is chlorine necessary in our network? Do we have a lot of it in our water supply network?

Chlorine is used as a disinfectant during the distribution and treatment of water. By disinfection we mean the destruction of pathogenic microorganisms contained in water.

Chlorination takes place on a 24-hour basis with modern technology at the central water treatment plants and at the points where water is made available to consumers from the central pumping stations.
The main form of chlorine used is anhydrous liquid chlorine (chlorine gas).

According to the legislation, water chlorination is carried out in such a way that a minimal amount of residual chlorine remains in order to deal with infections when distributing water to consumers. This small amount of residual chlorine is completely harmless to human health, since it is neutralised by saliva and gastric acid.

The disinfection of the distribution network of the Thessaloniki Urban Area is checked daily by the Drinking Water Laboratory Testing Department by measuring the free residual chlorine in the distribution network. The presence of residual chlorine is constant and is detected throughout the distribution network all the way to its endmost points, in accordance with the provisions of the health regulation.

The legislation also makes provision for the monitoring and measurement of chlorination by-products, which is carried out at the Water Treatment Plant Laboratory for the entire EYATH S.A. network, as frequently as is required by current legislation.
These are known as trihalomethanes and consist of the following four compounds: chloroform, bromoform, dibromochloromethane and bromodichloromethane. They are produced due to the reaction of the free chlorine in drinking water with the organic carbon that may be contained in it.

In accordance with current legislation, namely Joint Ministerial Decision No. Γ1(δ)/ΓΠ οικ. 67322/Government Gazette B 3282/19.09.2017, in compliance with Directive 98/83/EC on the quality of water intended for human consumption, as amended, trihalomethanes are measured 16 times a year and the total maximum parametric value should not be higher than 100 μg/l.

Based on the measurements carried out by the Water Treatment Plant laboratory, the concentrations of trihalomethanes in drinking water are far lower than the applicable statutory limit of 100 μg/l.

What can I do if the water smells like chlorine?

Consumers often complain that their tap water smells like chlorine.

In order to reduce the smell of chlorine, you can fill a glass bottle with water and leave it in the refrigerator overnight. The smell will have disappeared the next morning.
Caution! Refrigerated water in any container must be consumed within 24 hours.

Can I use a water tank or pressure booster pump?

If the water reaches your household through a water tank or pressure booster pump, there is a risk that the water may become infected due to stagnation and higher temperatures, and this water usually has fewer organoleptic properties compared to running water reaching your household directly from the water supply network. It should be noted that under the EYATH S.A. Water Intake Regulation, water tanks are prohibited for reasons of health protection of the water supply network (possible suction into the water supply system). For this reason, any connection to the water supply network (water meter column: meters) must have a check valve.

Home owners must ensure that any existing pressure booster pumps are regularly maintained and cleaned, as are any water tanks until their permanent removal, in order to avoid the degradation of the quality of the water they consume.

Should I install a filter at home?

We do not want anything to come between us!

  • The water meets all applicable national and European requirements in all respects (including heavy metals, pesticides, pathogenic organisms, etc.).
  • Any further treatment with the use of filters or any other means is therefore not necessary. It is redundant and adds unnecessary costs to consumers.
  • EYATH S.A. has processed, cleaned and disinfected the water, were and however necessary. In other words, EYATH S.A. has already done for us what any filter would.
  • When the Drinking Water Laboratory Testing Department gets to the consumer’s tap in order to collect a sample, it either requires that any filter or treatment unit installed by the consumer be bypassed or that samples be taken from taps that are not affected by it.
  • Sometimes filters, especially those that are not properly maintained but also those that are, can harm instead of improve the quality of the water both from a chemical and microbiological aspect.
  • “Desalination” filters that de-ionise water can even prove to be harmful to one’s health. A certain number of minerals is necessary for the proper function of one’s body. De-ionised water is non-drinkable!
  • Filters that consume residual chlorine long before the water reaches your glass can prove to be even more harmful to one’s health considering that, by “neutralising” the residual disinfectant effect of chlorine, it may render the water vulnerable to microbiological infection.

The Ministry of Health has pointed out that if a consumer chooses to add materials such as water filter appliances after the water outlet and on the tap, which is also the point of final control of water quality, in accordance with current legislation, then it shall no longer fall within the scope of competence of the bodies responsible for the quality of water following the interference of the filter.

Can I drink from the hot water line? The water is very cold in the winter.

  • Never drink water from the hot water or mixer tap. Drink only from the cold water tap!
  • The hot water line, even when mixed with cold water, does not provide drinking water. It may be chemically or microbiologically degraded!
  • If you need to use the hot water, once you are finished using the hot water turn it back to the cold water line and wait for it to regain its regular cool temperature before drinking.
  • You can check the water’s temperature with the tip of your finger whenever you turn on the tap to drink water.
  • When a household functions under normal conditions, it becomes immediately clear when standing water has been cleared from the internal piping and when the water running from one’s tap is the fresh, cool water from the network, which we can consume without hesitation.
  • The improvement of taste and odour following this simple test is truly impressive!

One does not need any filters, cotton wool and plastic bottles. EYATH S.A. Provides top quality water!

Does asbestos in the networks affect the quality of drinking water?

Asbestos is a fibrous silicate mineral that contains iron, magnesium, calcium and sodium. None of the elements it contains are harmful to one’s health when they are found in water in concentrations permitted by the regulations. However, its use in the construction of water pipes and the possible suspension of asbestos fibres in drinking water have sparked the interest of the public and have concerned various organisations. This interest and relative concern have been caused by the fact that inhaled asbestos fibres are carcinogenic.

The World Health Organisation claims that although the carcinogenicity of inhaled asbestos is well established, there is no conclusive evidence that asbestos ingested with drinking water has negative effects. This is the latest response to recent concerns arising from the use of asbestos cement in water pipes.

Circular No. ΔΥΓ2/19028 on “asbestos pipes in the water supply network” does not include asbestos fibres in the parameters that must be controlled in drinking water, and it further states: “As regards the health effects of swallowing asbestos fibres with drinking water, the conclusions of studies in the international literature have not established a direct correlation between the potential presence of asbestos fibres and health effects from swallowing such fibres”.

To date, asbestos fibres have not been detected in the drinking water of the Thessaloniki Urban Area. Analyses for the detection of asbestos fibres in drinking water are carried out on behalf of EYATH S.A. at specialised third-party laboratories. It should be noted that for this parameter there is no limit to.

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