| Consumption of domestic water in Europe | |||
| Nb litres / inhabitant / day | |||
| Belgium | 120 | ||
| Germany | 127 | ||
| Denmark | 145 | ||
| France | 156 | ||
| Austria | 162 | ||
| Luxembourg | 169 | ||
| Netherlands | 175 | ||
| Sweden | 191 | ||
| Switzerland | 237 | ||
| Italy | 249 | ||
| Norway | 260 | ||
| Source: BGW-Wasserstatistik 2002 | |||
THE SOURCE OF LIFE
Odourless, neutral in taste, colourless. Comparatively inconspicuous by itself, but present everywhere: water is there all the time – and indispensable! The first living being appeared some three billion years ago in the water, and the human body is made of roughly 70% water. Yearly individual consumption of the precious liquid is about 900 litres, because without drinking water we couldn’t exist.The paramount importance of water is to be traced to its property as a solvent and vehicle for many substances and gases. In nature water practically never appears in pure form, but is enriched in minerals such as sodium, potassium, magnesium and calcium.
Drinking water as delivered by water supply companies is subjected to the strictest regulatory controls, and is in perfect chemical and well as hygienic condition. However within legal limits one may find a wide spectrum of water qualities. These may be more precisely defined through water hardness, which is measured in od, of or mol/m3.Water hardness
Water hardness is necessary for mankind’s health, but from a technical point of view lime dissolved in water has its disadvantages. For while the body may thrive, lime may heavily clog pipes and domestic appliances. Lime spots on fittings and tiles, as well as higher energy costs due to lime deposits on heating elements must be mentioned here; not to forget the cost of pipe clogging through lime deposits.Soft water
On the other hand soft water favours corrosion symptoms. These range from reduced water pressure due to incrustations, to red-brown colouring of the water in steel pipes, and to leakage of water pipes due to corrosion.| Hardness range | Water hardness | German hardness | French hardness | Mol/m3 |
|---|---|---|---|---|
| I | Soft water |
< 8,4 od
|
< 15 of
|
< 1,5 |
| II | Mid-hard water | 8,4 bis 14 od | 15 bis 25 of | 1,5 - 2,5 |
| III | Hard water | > 14od | > 25 of | > 2,5 |