Chemical parameters

Copper in piplelines means that the use of copper pipes is therefore limited to certain potable waters. With certain, mostly hard, acidic potable waters with a high content of natural organic compounds, increased copper solubility can sometimes be observed. In conjunction with longer periods of downtime, this can lead to risky concentrations of copper significantly above 2 mg/l in the water.

Increased copper solubility is generally observed in new potable water installations made of bare copper. Depending on the water quality, it may last for a few weeks to months after commissioning. Exposure to more than two milligrams of copper per litre for several weeks to several months may be detrimental to the health of newborns and infants. There is no risk to children and adults, but potable water with more than three milligrams of copper per litre is often rejected for taste reasons. If the content is more than three milligrams of copper per litre, gastric and intestinal complaints may also be expected in the short term. (Always specify as mg/l).

Exceeding the parameter value for nickel is to be expected, above all, where nickel-plated components were used or chrome-plated end fittings are present where some of the surfaces in contact with the water have nickel layers which are not covered by the chrome layer. The resulting concentrations are harmless to people of normal health of any age. However, people who are pre-sensitised to the allergenic effects of nickel – equivalent to around one-sixth of the population – may be more sensitive.

Lead is a nerve and blood toxin that can accumulate in the body and may have an detrimental effect on the development of a child's nervous system. Therefore, pregnant women, unborn babies, infants and toddlers are particularly at risk and should be protected against the ingestion of lead. Other installation materials, such as galvanised steel or copper alloys, may also release lead into potable water. The German Environmental Agency (UBA)  specifies in a recommendation the materials suitable for potable water hygiene, for which it has been proven that they do not exceed the new lead limit value.

Since December 2013, a maximum limit value of 0.010 mg/l of lead in potable water has been in force in Germany. As a rule, this value cannot be met by potable water flowing through lead pipes. In combination with other metal materials, even smaller sections of lead pipes can result in high lead contents in the water. Therefore, when lead pipes are being replaced, it should be ensured that they are replaced in full. However, if lead pipes still exist, they should be replaced as soon as possible. Shut-off valves and domestic water meters made of copper alloys can also easily result in increased concentrations of lead. The zinc layer on hot-dip galvanised steel pipes is contaminated with lead during manufacturing. This can cause the potable water to be contaminated with lead, even if the potable water installation itself contains no lead pipes.

In contrast to Europe, no lead is permitted to be present in alloys in the USA.

‘Brown’ – rusty – water can be produced from older pipelines with galvanised steel after a longer period of downtime. Due to turbidity and a high iron content, such coloured water is not of a quality required by the regulations on potable water; however, it does not pose an acute health risk. However, this technical abnormality may soon pose a problem from a hygiene viewpoint and could be an indicator of a possible microbial contamination. Current pipelines made of stainless steel are suitable for all potable waters and are hygienically safe.