Frequently asked questions

Water quality

Does tap water contain lead?

Particular attention is paid to the presence of lead in drinking water. At the end of 2013, the European Union set a maximum lead content in tap water of 10 µg/l.

We are doing our utmost to meet this standard. 

To find out more, visit the page “Lead in tap water? ”

Can I drink tap water?

The water we distribute meets all European and Walloon health standards. It can therefore be drunk without restriction.

What do I do if my water is red or brown?

The natural composition of metal-laden water can, in rare cases, give it a brown or red colour. The metal content of the water can also be influenced by travelling through the pipes when the flow rate is increased, for example.   

This water is not harmful to your health, but, if you notice that the phenomenon is frequent and that the water is also coloured at the tap just after your meter, contact us.  

What can be done to get rid of this colouring? 

Let the water run for a few moments. 

After a long absence, drain the water that has been left to stagnate in the indoor pipes. 

If you notice any stains on your clothes, wash the dirty clothes again immediately.  

More information:

The water in your municipality

Water analysis

Is it necessary to install filters to improve the quality of tap water?

The water supplied by SWDE is perfectly drinkable. However, the taste of the water can vary depending on the region and the treatment it has undergone. It is not necessary to filter the water to improve its quality. However, if you do not like the taste of your tap water, you can, of course, use these systems. 

You can consult the Blue Book published by Belgaqua to find out all about drinking water and wastewater treatment.  

More information:

Contact us

The water in your municipality

 

Where does tap water come from?

A distinction is made between groundwater and surface water, depending on its origin. 

Groundwater is water from precipitation that has seeped into the ground. It is collected in different ways: 

from springs; 

  • via draining galleries; 
  • by drilling a well down to the water table; 
  • by pumping from old mines where water has accumulated. 
  • Surface water is drawn from rivers, canals, streams, lakes and reservoirs. 

You will find the exact source of the water you consume on the fourth page of your adjustment bill.  

More information:

Where does your water come from?

Treatment plants

What quality parameters must drinking water meet? Who sets these criteria?

Tap water must meet a large number of quality parameters. These are set by the standards of the Walloon Water Code. The water from our network is analysed daily to ensure that it complies with the standards.

How can I effectively flush the pipes in my home?
  1. Flush the toilets. 
  2. Draw three litres of water from each tap (if possible simultaneously). 
  3. Clean your tap filters. 
  4. Let the water run from each tap until it is clear. 

Be careful, after a water cut, the pipes may contain a lot of air. Opening a tap can cause so-called “water hammer”. To avoid damage, we recommend that you first carefully open the cold water tap located just after the meter. 

Legionellosis: what are the risks?

Legionellosis is a potentially fatal disease caused by a bacterium, Legionella, which is quite common in nature. It is found in small quantities in most surface waters. It thrives best in warm stagnant water (± 40°C). It cannot survive temperatures above 60°C and dies relatively quickly.

Read more:

Legionellosis: what are the risks?

Why does tap water sometimes smell and taste like chlorine?

Effective disinfection of tap water is absolutely necessary to prevent the recurrence of potentially fatal infectious diseases. Chlorine is injected into the water at very low levels (safe for your health) to prevent it being contaminated by pathogenic viruses or bacteria between the production site and your tap. 

A litre of tap water can contain a maximum of a quarter of a milligram of chlorine. 

As chlorine evaporates in the open air (and not in the pipes), its taste disappears very quickly if the water is left to stand in an open jug.

Why is water from the hot water circuit not drinkable?

Hot water refers to water from a boiler or from a combined central heating hot water tank. This water is no longer classed as drinking water, even if it is cooled afterwards, because the warming causes many changes: 

  • some bacteria take advantage of the favourable temperature to multiply, especially in parts of the circuit where the water is warm rather than really hot; 
  • hot water accelerates corrosion, dissolves certain substances in the pipes more easily and can therefore contain significantly more copper, iron, nickel, zinc or lead than cold water. 

So always use the cold water tap for drinking, cooking and even making hot drinks. If you have a mixer tap in your kitchen, make sure it is in the "cold water" position and let some water run out before you use it. 

More information:  

The benefits of tap water

Is SWDE water suitable for filling my aquarium?

Yes, tap water is suitable for most aquarium fish. However, care must be taken with species that require water with specific characteristics. It is advisable to seek specialist advice when buying your fish.

 

The water in your municipality

Does tap water contain pesticides?

The European standards governing the level of pesticides in tap water (and applied in Belgium) are much stricter than the recommendations of the World Health Organization. In Wallonia, only 1/10 of a thousandth of a milligram per litre of water (0.1 µg/l) is allowed per substance and just 1/2 of a thousandth of a milligram per litre of water (0.5 µg/l). 

Compared to the consumption of many other everyday foods, the proportion of pesticides in tap water is very small.
 

In your municipality

 

Tap water contains limescale; is it bad for my health?

Generally speaking, tap water of underground origin naturally contains limescale. When water filters down, it passes through several types of soil with different geological characteristics. It then becomes loaded with minerals and trace elements, including calcium carbonate. 

The limescale dissolved in the water is not bad for your health. On the contrary, it provides the calcium essential for growth and necessary to prevent decalcification. 

More information: Installing a water softener

 

Is rainwater suitable for some domestic uses?

You can use rainwater for flushing toilets and watering your garden. Some urban planning regulations require the installation of rainwater tanks in new buildings. 

However, it is not drinkable and its quality is not reliable enough for regular personal hygiene (bathing, showering, brushing teeth, etc.). 

If you install a rainwater system in your home, it is essential that it is completely and permanently separated from the drinking water system to avoid contaminating the latter. 

More information:  

Non-return valve 

CertiIBEeau 

 

My water sometimes has a temporary milky appearance. Why is that?

The milky appearance is due to the appearance of fine air bubbles in the water and not to limescale. The play of light on the water gives it that characteristic milky appearance. 

Within a minute, the air bubbles rise to the surface and disappear. The water then becomes perfectly clear again. This phenomenon has no effect on water quality. 

More information:

The water in your municipality 

Is water from the natural environment safe to drink in its raw state?

Regardless of its source (underground or surface), water drawn or harvested from the natural environment must undergo treatment. It is therefore not recommended to drink it in its raw state. 

More information:  

Where does your water come from?  

Treatment plants

 

Is tap water healthy?

Tap water is healthy ir. However, if you are going to be away for a long time, let your water run for a while (and keep it for other uses, such as watering) before drinking the water from the tap. Stagnant water can dissolve certain substances in the pipes.If your home still has lead pipes, these can be harmful to your health.  

If the water smells of chlorine, fill a jug and wait a few minutes. The chlorine will evaporate. 

More information:  

Tap water is drinking water 

Water is good for your health

 

What is the composition of my tap water?

The composition of the water varies depending on when and where it is collected. Your tap water may be the product of a mixture of water from different sources. Its composition may also depend on the flow rate of each catchment. Regardless of these variations, the drinking water in our network always meets the legal standards. 

 

See the water quality for my address

 

When is water said to be aggressive? Does it cause rusting and accelerate pipe corrosion?

The higher a water’s calcium and magnesium content, the “harder” it is. Conversely, water with a low limestone content is said to be “soft”.  

Aggressive water is soft water with an acidic pH.  

It degrades the pipes, removing the thin protective layer that may have formed over the years on the inside of them. The metal is then exposed and corrosion can occur. If the pipes are made of iron or steel, rust may form. Alteration of lead piping carries health risks. 

We take care to provide non-aggressive water, the composition of which favours the formation of a thin protective layer of limestone in the pipes. 

The most common causes of corrosion in an indoor facility are: 

  • the use of poor quality materials; 
  • poor thermal balance of domestic hot water recirculation circuits; 
  • the use of improperly adjusted water softeners; 
  • the presence of deposits or incrustations in the pipes; 
  • the presence of air in the pipes; 
  • incorrect placement or use of pipes of insufficient diameter (corrosion by erosion); 
  • stray electrical currents. 

All these problems can be prevented during installation. For this reason, it is best to call in a professional. 

More information: How to deal with leaks

What to do if your tap water tastes "musty"?

First of all, it is important to identify the origin of this "musty" or mouldy taste. It can come from the public supply network or from the pipes inside the house. To find out, draw water immediately after the meter at the stopcock. If this bad taste is present at the meter, contact us

If the water does not have a taste or odour problem at the point where it comes into the building, the problem is in the internal installation. In this case, a purging of the internal pipes should help return it to a normal situation.

Water and asbestos, what do you need to know?

Can I inhale asbestos from tap water?  

Under certain conditions, water intended for human consumption can be aerosolised (air from showers, etc.) and inhaled in very small quantities. As the asbestos fibre content in the tap water is zero or particularly low, the amount of asbestos fibre inhaled would be minuscule. 

Am I taking a risk by ingesting asbestos? Do we risk the same effects as when we inhale asbestos?  

While the risk of asbestos inhalation has been clearly identified for decades, the same cannot be said for asbestos ingestion, for which the risk is not yet known. To date, there are no European standards or Walloon legislation on the subject, which is explained by the reassuring conclusions of scientific studies and the World Health Organization (WHO). 

Do asbestos cement pipes pose a health risk?  

According to current scientific knowledge, the levels of asbestos fibres found in water do not constitute a health hazard. In Europe and in Wallonia, there is no health standard for asbestos fibres. The US has set a health standard of 7,000,000 fibres per litre. This content has never been found in our analyses. 

Can roof, cistern or well water contain asbestos?  

Water that comes into direct contact with asbestos cement materials could, under certain conditions, contain asbestos fibres. For example, if the asbestos cement material is friable (degraded by temperature variations between winter and summer) and the water that comes into contact with it has aggressive properties (which is characteristic of rainwater), then it is possible for the water collected to contain asbestos fibres. 
The risk of harvested rainwater containing asbestos is therefore much higher than that for tap water. 

Can tap water contain asbestos?  

Rarely and in very small quantities. 

90% of the pipes in our network are not made of asbestos cement but of other materials (steel, ductile iron, grey iron, PVC, polyethylene, etc.). 
When water flows through an asbestos cement pipe, it is possible, under very specific conditions, for asbestos fibres to be released into the water, but these are minute quantities. 

Does SWDE test for asbestos in all municipalities?  

There are municipalities where there are no asbestos cement pipes. It is therefore unnecessary to carry out special tests. We carry out water quality control in municipalities with asbestos cement in the network. 

Are customers in the vicinity of an asbestos site warned?  

The measures taken on the sites to avoid the projection of asbestos fibres into the surrounding air, such as the use of slow saws and spraying continuously with water during cutting, as well as the location in a trench, sheltered from the wind, do not require the local residents to be informed.  

On the other hand, sites of this type must be notified to the Regional Directorate for Workplace Welfare Control (FPS Employment, Labour and Social Dialogue) in order to check that the legislation and, in particular, the worker protection measures are respected and correctly implemented. 

Does SWDE take the opportunity to replace asbestos cement pipes on roadworks carried out by other road or network managers?  

Yes, we systematically review every appropriate opportunity that arises to renew our pipes. The choice is made on the basis of a multi-criteria tool that allows the decision to be made objectively, regardless of the pipe material. Particular attention is paid to construction sites where the nature of the work could weaken the asbestos cement pipes. 

Won't the wear and tear of the asbestos cement pipes cause even more asbestos to be released into the water?  

With our analysis campaigns, we monitor changes to our asbestos cement pipe network. If abnormal wear and tear of our pipes were to endanger the health safety of our customers, we would make every effort to renew them as a matter of priority. 

Where are asbestos cement pipes laid?  

The distribution of this type of pipeline in Wallonia is not consistent. Some municipalities have a network composed of a double-digit percentage asbestos cement pipes, others have none at all. We know the location, nature (material) and other characteristics such as diameter, date of laying, etc. of all the pipes in our networks, including those made of asbestos cement. 

Where does asbestos waste from asbestos cement pipe replacement sites go?  

The disposal of waste materials containing asbestos is subject to legislation that is reflected in the operating procedures applied within SWDE. From the start of the work, the waste is packaged in specific containers with the personal protective equipment used by the personnel. They are collected by an approved firm for disposal in centres that are themselves approved for this type of waste. 

Why have all these pipes not already been systematically replaced? Why not draw up a specific plan for the urgent replacement of asbestos cement pipes? What is your plan to replace these pipes in the coming years? 

There is no need to plan a systematic replacement of asbestos cement pipes as no scientific study has been able to demonstrate that oral ingestion of asbestos fibres in drinking water would have an impact on health, a conclusion which is confirmed by the World Health Organization (WHO). 
In general, asbestos cement is insensitive to internal corrosion and stray current corrosion.  
Our pipe replacement strategy incorporates the asbestos parameter. We use a multi-criteria tool to define renewal priorities, taking into account the nature of the pipes and their age. We invest €100 million each year in the renewal of our infrastructure, of which more than €60 million is spent on pipes. 

Why not disclose the streets where these pipes are located?  

The exact mapping of the pipelines is not provided for reasons of network integrity and public safety. Neither a diagram nor a list of streets is representative of a risk related to water quality as it flows through the pipes, since, for example, there may be pipes constructed of different materials in the same street. 

Why not have more regular analyses of the presence or absence of asbestos?  

Asbestos in water is not a standard parameter. There is therefore no defined testing frequency. However, we do carry out our own analysis campaigns at relevant points in our network to monitor changes to our network. 

Why is it that asbestos fibres can sometimes be detected when sampling fire hydrants, but not at customers' taps?  

Hydrants are special elements of the network. Their location in the branch of the pipe and their configuration mean that they are like small "dead ends" of stagnant water where fibres can become trapped and be released when the network is purged. 

Why are there asbestos cement pipes?  

In the aftermath of the Second World War, the demand for building materials was enormous and many small and medium-sized municipalities were equipped with a drinking water network. Asbestos cement pipes produced in Belgium were an innovative alternative to the much sought-after materials steel and grey cast iron. In addition to being lighter than metal pipes, asbestos cement pipes had useful characteristics in terms of compressive strength, tensile strength and bending strength, as well as an absence of internal corrosion which, with metal pipes, can cause coloured water over time. 
No more asbestos cement pipes have been laid since the late 1970s. 

What is the treatment to remove asbestos from water?  

The asbestos fibre content in the water supply is zero or very low. It is therefore not necessary to treat the water to remove the asbestos. 

What information will you be providing? Will you publish your new analyses?  

In December 2022, SWDE took tap samples from residents in Frasnes-Lez-Anvaing and Wanze. The analyzes did not reveal the presence of any trace of asbestos fibers.

In March 2022, SWDE conducted an asbestos analysis campaign on its distribution network. Sampling was carried out at residents' taps, at the same locations as the previous campaign in 2018, and where the greatest number of asbestos cement pipes remain. The municipalities concerned are: 
 
Bernissart - Bertogne - Brunehaut - Braine-l'Alleud - Burdinne - Couvin - Doische - Ecaussinnes - Ellezelles - Estinnes - Frasnes-lez-Anvaing - Les Bons Villers - Mons - Namur - Péruwelz - Ramillies - Seneffe - Soignies - Viroinval - Wanze - Waremme 
The municipal authorities are informed of the results as they are received. 

With three exceptions, no traces of asbestos fibres were detected in the 70 samples taken and analysed by an independent laboratory. Micro-traces were detected in Couvin and Doische. New analyses carried out after a purge of the network gave, in turn, 100% negative results. Several of these municipalities wished to carry out additional analyses. None of them revealed the presence of any asbestos.

What measures does SWDE take to deal with asbestos work sites?  

We have an aggressive and consistent policy to protect our workers when working with asbestos. We have strict and safe working practices in place when cutting asbestos cement pipes.  

Based on internal procedures and operating methods, we provide annual training on asbestos-related risks to our field staff. They all have a manual reminding them of the precautions to be taken with regard to the workers and people living in the immediate vicinity of the site during interventions, as well as a kit of single-use personal protective equipment. 

 
In addition, we also inform our subcontractors through the Health and Safety Prevention Plan (HSPP) attached to the specifications governing the contracts. We also provide training sessions on asbestos risks and precautions.  

Finally, our safety department (SIPPT) and our managers carry out site visits throughout the year, during which a predefined list of safety points are checked. The use of the "asbestos kit" is a recurring point in the rating, which is followed as an objective for our intervention teams. 

How can it be said that asbestos cement pipes do not cause the presence of asbestos in tap water?  

The various analyses that we carry out via an independent laboratory on our customers' taps show that no asbestos fibres have been detected.

In December 2022, SWDE took tap samples from residents in Frasnes-Lez-Anvaing and Wanze. The analyzes did not reveal the presence of any trace of asbestos fibers.

In March 2022, SWDE conducted an asbestos analysis campaign on its distribution network. Sampling was carried out at residents' taps, at the same locations as the previous campaign in 2018, and where the greatest number of asbestos cement pipes remain. The municipalities concerned are: 
 
Bernissart - Bertogne - Brunehaut - Braine-l'Alleud - Burdinne - Couvin - Doische - Ecaussinnes - Ellezelles - Estinnes - Frasnes-lez-Anvaing - Les Bons Villers - Mons - Namur - Péruwelz - Ramillies - Seneffe - Soignies - Viroinval - Wanze - Waremme 
The municipal authorities are informed of the results as they are received. 

With three exceptions, no traces of asbestos fibres were detected in the 70 samples taken and analysed by an independent laboratory. Micro-traces were detected in Couvin and Doische. New analyses carried out after a purge of the network gave, in turn, 100% negative results. Several of these municipalities wished to carry out additional analyses. None of them revealed the presence of any asbestos.

Are asbestos cement pipes dangerous to health?

Asbestos is dangerous by inhalation, not because it is toxic, but because some fibres can settle in the lungs and damage the tissue there. This also poses a risk for our workers, who must take appropriate protective measures when working on asbestos cement pipes.

Can I drink water drawn from my well?

It’s best not to! Water from a private well may look or even taste good but still be unsuitable for food consumption because it is contaminated. The risk of water pollution is even greater if the well is shallow. We sometimes draw our water from a depth of more than 200m.  

At shallow depths, pesticides, nitrates and bacteria can easily penetrate and these harmful substances have no taste, colour or smell.  

We therefore advise you to have your well water tested regularly. In addition, be aware that water from a well must be piped completely separately from tap water to avoid any contamination. 

More information:

Have your water analysed 

CertIBEau

Are there any constraints on installing a rainwater tank?

If you wish to equip your home with a rainwater tank, there are mandatory measures to follow. For example, you must create a complete separation between the drinking water network and your cistern network. Your health and the health of other customers depend on it.

More information:

CertIBEau

What should I do if I have doubts about the quality of my water?

Water quality must meet the legal standards applicable to drinking water. This quality is strictly controlled, but a problem cannot be ruled out completely. 

If in doubt, contact us. We will always look into your query carefully.If necessary, we will send a technician on site for further investigation. They may take water samples. The laboratory analysis will determine any corrective measures to be taken to bring the situation into compliance. 

More information:

In your municipality

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