In France, the law is evolving to facilitate the reuse of wastewater
With the One Water Summit taking place this December 3, alongside the COP16 meeting on desertification in Riyadh, the question of water governance is becoming increasingly relevant in the context of the fight against climate change. Although promoted some fifteen years ago, the large-scale reuse of treated wastewater has long been held back by overly strict regulations. Recent regulatory developments in France, broadening the scope of its uses and relaxing the conditions under which it can be applied, offer hope for wider deployment of the practice.
Julie Mendret, University of Montpellier and Thomas Harmand, Aix-Marseille University (AMU)
This December 3, the One Water Summit is being held alongside the COP16 on desertification in Riyadh. It has to be said that the issue of water governance is becoming increasingly important in the context of the fight against climate change. The reuse of treated wastewater (known as "REUT"), for example, which consists of recovering and treating water from domestic, industrial or agricultural activities in order to reclaim it for various non-drinking uses, rather than discharging it into the environment as is usually the case.
This practice aims to preserve drinking water resources by substituting treated water for abstraction from groundwater or rivers. In France, it is increasingly seen as a solution to water shortages and recurring droughts.
Nevertheless, the current regulatory framework is regularly singled out as a brake on its development. Although a framework is necessary to guarantee the sanitary safety of this method, the regulations present a number of application constraints that slow down the large-scale adoption of LWR.
However, the legal framework surrounding the reuse of unconventional water has grown considerably over the past year and a half, with no fewer than eight new texts published between August 2023 and September 2024. The aim of these regulations is to simplify the implementation of UWWR and define a framework for all possible uses.
A far-reaching reform of the regulatory framework
Until recently, the regulatory framework for LWR in France dated back to a decree promulgated in 2010 and amended in 2014.
In 2020, the European authorities took up this issue by promulgating Regulation (EU) 2020/741 of the Parliament and of the Council of May 25, 2020 on minimum requirements for the reuse of water. This regulation is directly applicable on the territory of EU member states, and forms an integral part of French law from its entry into force, which was set for June 26, 2023.
It lays down minimum quality and monitoring requirements for treated wastewater (TWE) to be reused for agricultural purposes, adopting in particular a "multi-barrier" approach which is a method for better risk management.
The regulation also left it up to the Member States to adopt additional provisions. Following the adoption of this regulation, a decree dated March 10, 2022 was published in France, extending the possibilities for reusing TMEs to all uses other than food, hygiene or approval.
1,000 projects by 2027
The French government's Water Plan, announced in 2023, highlights the reuse of treated wastewater (REUT) as a flagship measure for tackling the challenges of water management.
This ambitious plan aims to develop 1,000 reuse projects by 2027 and achieve a rate of 10% of treated wastewater by 2030, compared with less than 1% today. The government hopes to increase tenfold the volume of wastewater reused for non-drinking purposes, such as agricultural irrigation, urban cleaning and fire-fighting.
This initiative is part of a wider strategy for the sustainable and resilient management of water resources, essential in the face of the impacts of climate change. The objective is very clear : to develop the use of unconventional water resources.
Still too much drinking water to clean the streets
The aforementioned decree of March 10, 2022 was repealed by the decree of August 29, 2023 on the use and conditions of use of rainwater and treated wastewater, which simplified the authorization procedure, notably through the introduction of a one-stop shop.
These include traditional uses such as agricultural irrigation and watering green spaces, as well as urban uses such as street cleaning, watering networks and fire-fighting. In France, many cities clean their streets with drinking water!
This decree of August 2023 was supplemented by two orders, published on December 14 and 18, 2023 respectively, setting out the conditions for the production and use of treated wastewater for watering green spaces and irrigating crops.
In line with the provisions of the 2020 European regulation, uses are strictly regulated, in particular by the quality levels to be achieved. The quality levels established are ranked from A to D, from best to worst, and the uses permitted depend on the quality of the TMEs available. A quality TME, for example, can be used to irrigate the edible part of food crops eaten raw.
Relaxed rules to promote practice
Lastly, certain uses of TMEs have been authorized in the food sector thanks to the recent decree of January 24, 2024, which sets out various provisions relating to the safety of water intended for human consumption.
The latter was amended and supplemented by a decree and order dated July 8, 2024. The permitted uses concern the preparation, processing and preservation of all foodstuffs and goods intended for human consumption.
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The use of TMEs as ingredients is not authorized, but the use of "recycled water from raw materials" and "recycled process water" as ingredients is. These texts define the conditions under which such water can be reused in food companies.
These recent regulatory developments in France, notably the 2023 decree, show an increased willingness to promote wider adoption of WASW in France, despite the continuing restrictions to ensure sanitary safety. Developing this practice appears crucial to preserving drinking water resources, meeting climate challenges and ensuring sustainable water management. By encouraging innovative projects and easing certain constraints, France can become a leader in the responsible management of this vital resource.
Julie Mendret, Senior Lecturer, HDR, University of Montpellier and Thomas Harmand, PhD student in water law, Aix-Marseille University (AMU)
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