What is REUT?
Reuse of Treated Wastewater (RTWW) Reuse of Treated Wastewater (RTW) refers to the practice of giving water a second life after treatment by reinjecting it into non-potable uses such as irrigation, cleaning, or industrial cooling. This approach is part of a strategy of water conservation, in response to growing pressure on water resources.
In France, REUT remains marginal:less than 1%of wastewater is reused, compared to 8% in Italyand14% in Spain . However, globally,80% of wastewateris still discharged without being reused. This observation highlights the urgent need for a paradigm shift in industrial water management.
Understanding the water cycle as altered by human activity
The work of INRAEhighlights highlights three major disruptions to the water cycle caused by human activity:
- The direct use of water for agriculture, livestock farming, or industrial processes.
- Soil modification through urbanization, deforestation, or intensive agriculture, which alters evapotranspiration, groundwater recharge, and river flow.
- Climate change, which alters water flows and storage at all scales.
Contrary to popular belief, two-thirds of precipitation does not come from marine evaporation, but from evapotranspirationevapotranspiration from soil and plants . The water absorbed by plants is largely redistributed into watersheds, contributing to the regeneration of local rainfall. Preserving this water cycle is therefore essential to prevent aridification of territories.
Why increase the share of REUT?
In a context of increasing water stress, REUT appears to be a strategic solution for manufacturers:
- It allows for reduce withdrawals from groundwater and waterways.
- It helps to preserving the habitability of territories, particularly during periods of drought.
- By limiting direct discharges into the sea and promoting local infiltration or reuse, eit avoids disruption of the small water cycle.
The drought decrees, such as the one of June 30, 2023, impose up to 20% reduction in water withdrawals during periods of crisis. Manufacturers who implement a austerity plan or who reuse at least 20% of their water may be exempted from these restrictions, thereby ensuring continuity of their activity.
