Where our drinking water comes from

Water is the main component of everything we eat. A human being - comprising more than 60% water - uses two and a half litres of this precious liquid during everyday activities, water that is absorbed by the body from both food and drink. A human being can live for several weeks without food, but cannot survive for much more than three days without water.

The daily consumption of drinking water in the Grand Duchy is about 115,000 cubic metres. Two-thirds of this water come from underground resources (groundwater), and the remaining third from treated surface water. All the water thus collected or treated is distributed by the municipal authorities to their residents.

The municipalities are divided into three categories according to where their drinking water supply comes from:

• autonomous municipalities providing their supply of drinking water exclusively from their own springs and wells;
• municipalities affiliated to a water syndicate that provides them with drinking water, which they then distribute to consumers;
• semi-autonomous municipalities having their own sources but also receive water from a syndicate to meet their requirements.

The following syndicates supply water to municipalities:

• Esch-sur-Sûre water syndicate (Syndicat des Eaux du Barrage d’Esch-sur-Sûre - SEBES);
• Ardennes water distribution syndicate (Syndicat Distribution d’Eau des Ardennes - DEA);
• South Koerich water syndicate (Syndicat des Eaux du Sud Koerich - SES);
• inter-municipal syndicate for the distribution of water in the eastern region (Syndicat Intercommunal pour la Distribution d’Eau de la Région de l'Est - SIDERE);
• water syndicate for the centre (Syndicat des Eaux du Centre - SEC);
• water syndicate for the south-east (Syndicat des Eaux du Sud-Est - SESE).

These syndicates produce drinking water from their own resources and also receive supplies from the SEBES.

Drinking water from groundwater

Groundwater circulates through gaps in permeable rocks. Because groundwater is out of sight, its importance and its volume are often under-estimated. As is passes through the rock, groundwater is filtered. Groundwater must be tapped in such a way that it does not enter into contact with surface water, which always contains germs and micro-organisms.

There are two main ways of tapping groundwater:

• using a spring-box, which is a structure placed around a natural upwelling of groundwater (a spring);
• using a bore-hole, which may be of variable depth.

The water is pumped up to the surface.

Drinking water produced from surface water

Drinking water from surface water is produced at the Esch-sur-Sûre reservoir. Production of this kind involves complex treatment, carried out by the SEBES. Its processing plant currently has a capacity of 70,000 cubic metres per day.

Whenever demand for drinking water exceeds this capacity, the SEBES tops up its production by using groundwater from bore-holes.