Lead in your tap water?


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.


SWDE and lead

We have invested and continue to invest in replacing all remaining lead connections in the network. Only a small proportion of our connections are still made of lead. Our aim is to replace them all by 2024 at the latest. For these investments to be fully effective, it is also essential to remove lead from private systems. Most buildings/housing built before the 1960s still have lead indoor pipes. 

We therefore encourage you to replace lead pipes in your private system as soon as possible.   



Samples are regularly analysed to ensure that the water supplied by our network meets drinking water standards.  

What does the current legislation say? 

" Tap water must satisfy 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.  If an analysis at a customer's home shows a lead content at the meter of more than 10 micrograms per litre or if a lead connection is newly identified, we will arrange for it to be replaced within 60 days. For this measure to be fully effective, building owners must also replace or treat any lead pipes in their installations located in their property after the water meter. ”

Why is there lead in tap water? 

Water leaving the catchment or treatment plant does not contain any lead.

Underground transfer pipes are also lead-free. 

The connection, in the section of pipe between the main transport pipe running in the street and your meter in the building and/or the private property, is likely to be made of lead.

The presence of lead in tap water is mainly due to lead dissolving in pipes containing this metal (e.g. lead, galvanised steel and some brass pipes).

The extent of this dissolution varies according to several criteria:  

  • the length of stagnation of water in the pipes;  
  • the length and diameter of the pipes;  
  • the composition of the water. Acidic and/or low mineral water accelerates the dissolution of lead in water;  
  • the temperature of the water. Lead is twice as soluble in water at 25°C as at 15°C;  
  • the phenomenon of electrolysis (if the pipes are used as an earth connection, for example).  

What are the dangers and consequences of lead in tap water? 

Lead is dangerous to health when it accumulates in the body in excessive quantities. It can then cause the disease known as lead poisoning.  

In Wallonia, there are no known cases of lead poisoning related to the ingestion of lead via drinking water.  

How do you recognise lead? 

Lead is a dull (non-shiny), silver-grey metal. It is not magnetic (you can test this with a magnet) and is also very malleable and not very straight. At one time, lead was a popular metal for small-diameter water pipes precisely because of its malleability. 


It should not be confused with galvanised steel, which is rigid, generally grey (see photo below) and emits a clear sound when tapped lightly. When you place a magnet on the pipe, it stays attached. It is perfectly straight. It is impossible to leave a trace on it with your fingernail. 

Acier galva

Polyethylene ("plastic" material often called "Socarex") pipes are black and/or blue in colour (see photo below). These pipes are relatively flexible and make a hollow sound when tapped lightly. 


Copper is generally smaller in diameter than galvanised steel, and has the characteristic colour of metallic copper. 

What do you do if you have lead pipes in your private system?

While waiting for your lead pipes to be replaced, you can take some preventive measures:  

  • do not drink your tap water in the morning or when you are away for a long time. Let the water run for a short time first and reserve the initial water for other uses such as cleaning, flushing the toilet, watering, etc. Water that has been sitting in a lead pipe may contain high levels of lead. What is the ideal solution? Flush the toilet before making coffee in the morning;  
  • never use hot tap water for food;  
  • maintain the fittings regularly. Dismantle and clean the jet breakers (fine screens) of the taps to remove accumulated dirt;  
  • do not turn on your tap too suddenly when you want to take water for food. A sudden change in the flow rate can cause lead particles to be released and end up in the water being consumed;  
  • avoid using a water softener as softened water allows the solubilisation (dissolving) of lead in the pipes.   

Short summary

  • We are doing everything possible to replace the lead pipes that are still in our network. 

  • The water supplied by our distribution network complies with the standards established at the end of 2013 by the European Union. 

  • If there are lead pipes in your system, reduce the risk of ingestion by following the advice given above. 

Frequently asked questions

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.

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:

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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.