On a daily basis, what uses the most drinking water are flushing toilets at the rate of one third of the total consumption of a household, or more or less 30 liters per day. In second place is personal hygiene. Finally, the remaining third is consumed for cooking, washing machines and dishes.
However, alternatives to drinking water exist, such as rainwater for toilet flushing. However, it is still necessary to have enough space to be able to harvest it and the financial means “because you need the tank, you need the earthworks, you need the connections, you need the protections, you need the filters and a whole series of other things. Rainwater is therefore not free rainwater, it is still necessary to invest fairly large amounts. For example, typically, for a rainwater cistern which is connected to the WC and which is sufficient, it is necessary to count on the order of 2000 to 3000 euros“, emphasizes Cédric Prevedello.
[…] we have a screening that is in progress, […] which shows that the levels in groundwater are lower than those that can be found in rainwater thanks to this soil filtration mechanism
Another solution, in the medium term, would lie in the natural filtration of groundwater, particularly in Wallonia. “That is to say that when the water percolates towards the aquifers, it is filtered by the different layers of soil, which gives water of fairly good quality, with the exception of the exploitation of nitrates or pesticides that are found regularly. These are qualitative problems on which we are working with the sectors concerned. But at the level of perfluorinated substances, for example, we have a screening which is in progress, which has already been done in Flanders for example, and which shows that the levels in groundwater are lower than those which can be found in water of rain thanks to this soil filtration mechanism“, concludes the scientific adviser.