The natural water cycle consists of water passing from the sea to the atmosphere by evaporation (cloud formation), from the atmosphere to the earth by precipitation (river formation...) and then from the earth back to the sea, repeating itself indefinitely. However, to meet human needs, installations and a circuit have been set up. This makes the water drinkable and treats wastewater before reintroducing it into the environment. The "small water cycle" describes the path taken by water from its extraction from a river or groundwater to its return to nature, after having passed through the drinking water and wastewater treatment circuits for human consumption.
In France, tap water is one of the most closely monitored foodstuffs. It is subject to ongoing sanitary monitoring, designed to guarantee its safety. However, the presence of micro-organisms and other chemical components can sometimes be detected. Despite this, the risks to the consumer are low, and sanitary measures are rapidly taken by the authorities. In exceptional circumstances, with indications from official local authorities (such as groundwater contamination in some areas after heavy rainfall), tap water may lose its potability. Full details are available from the Direction Départementale des Affaires Sanitaires et Sociales (DDASS) in the region concerned.

You can access the results of sanitary control of drinking water quality commune by commune here: sante.gouv.fr

For further information, we recommend that you consult :

- OFB : The small water cycle