The REUSE decree is a French regulatory framework designed to encourage the reuse of treated wastewater (REUT) for agricultural, industrial or urban uses. This regulation establishes the quality standards and procedures to be followed in order to protect health and the environment while optimizing water resources.
Essential for preserving fresh water, wastewater reuse contributes to industrial, agricultural and urban sustainability.
Find out in this article about the benefits, regulations, technologies and solutions surrounding this increasingly fundamental practice for the "recycling" of water resources and the "reuse" of treated wastewater, as well as the importance of the "Reuse" concept.
Industry is one of the world's biggest consumers of water, accounting for around 25% of global demand. The reuse of treated wastewater in this sector offers an opportunity to reduce freshwater consumption and improve the sustainability of industrial activities. In times of drought, this practice also helps to ensure the long-term viability of industrial operations.
The benefits of this approach are manifold, ranging from reduced water treatment costs to reduced pressure on natural resources. Water reuse can be optimized through advanced technologies and successful case studies, as we shall see in the following sections.
Wastewater treatment technologies for industrial applications are varied and sophisticated. Multi-barrier treatment systems make it possible to produce a new, virtually inexhaustible resource from wastewater. Treated wastewater can be disinfected by UV irradiation and/or chemical means, guaranteeing clean, safe water for industrial reuse.
Industrial water, often contaminated by chemicals, requires specialized technologies to treat it before reuse. These technologies not only purify the water but also recover valuable elements, thus contributing to a circular economy.
Industrial case studies show that controlling calcium, magnesium and silica concentrations is essential to limit the risks associated with using recycled water in industrial boilers. By controlling these parameters, industries can avoid corrosion and deposit problems, thus ensuring safe and efficient use of recycled water.
Agriculture is the world's largest consumer of water, accounting for around 70% of global demand. The reuse of treated wastewater for agricultural irrigation offers a sustainable solution to the growing scarcity of freshwater resources, exacerbated by drought and climate change. By using treated wastewater, farmers can not only conserve fresh water but also improve food security.
This practice offers significant economic and environmental benefits. Treated wastewater often contains nutrients beneficial to crops and biodiversity, reducing the need for chemical fertilizers. What's more, reusing this water limits the use of pesticides and other toxic inputs, thus protecting soil and crops.
The economic and environmental benefits of reusing wastewater in agriculture are numerous:
Treated wastewater contains organic matter that can limit the use of pesticides and other toxic inputs, with positive impacts on public health. What's more, implementing wastewater reuse can help reduce the costs associated with water treatment and distribution.
Real-life examples show that treated wastewater is richer in nutrients, reducing the need for crop fertilizers. This nutrient-richness not only improves crop yields but also reduces the costs associated with the purchase of chemical fertilizers, offering an economical and environmentally-friendly solution for agricultural irrigation.
In urban areas, the reuse of treated wastewater from rainwater, for example, can be applied to non-potable uses such as watering green spaces and cleaning streets. This practice reduces the consumption of drinking water, thus preserving freshwater resources for more critical uses. Treated wastewater can also be used for applications such as watering green spaces, cleaning sewage pipes, air conditioning buildings, leisure for golf courses, washing roads and vehicles.
Implementing this practice requires an adequate infrastructure, including a dual distribution network to avoid contamination. In addition, strict disinfection and quality control requirements are essential to guarantee the safety of these uses.
A network separate from the drinking water network is essential for the distribution of treated wastewater. This infrastructure includes specific distribution systems to prevent cross-contamination with drinking water.
Black water, containing faecal matter and urine, requires complex treatment before it can be reused for non-drinking purposes.
Safety and quality requirements for urban non-potable uses include additional filtration and disinfection treatment after biological treatment.
Strict, regular monitoring of distribution systems is recommended to guarantee the microbiological quality of the water. These measures ensure that reused wastewater is safe for urban applications, thus protecting public health.
Reusing wastewater for drinking water is a promising but technically complex practice. It requires advanced methods to remove contaminants and guarantee the safety of the water produced. Although this approach is being adopted in some regions, it faces psychological and cultural constraints, as wastewater is often perceived as unhealthy and irreversibly contaminated.
Some cities around the world are already served by unplanned wastewater reuse schemes, demonstrating the feasibility and safety of this practice. However, for wider adoption, it is essential to overcome regulatory hurdles and gain public acceptance, particularly with regard to project management of the water plan promulgated by the President of the French Republic.
Advanced treatment processes for drinking water include several fundamental steps:
These steps are essential to remove solid particles and organic matter. Next, ozonation or UV disinfection is used to neutralize viruses and pathogenic bacteria.
Technologies such as reverse osmosis and membrane filtration, like ultrafiltration and nanofiltration, are also commonly used to remove microbiological and chemical contaminants. These techniques ensure that the water produced is safe for human consumption, meeting the most stringent quality standards.
Regulatory frameworks for drinking water from treated wastewater must ensure levels of sanitary safety compatible with national and international standards. Public acceptance is often a major hurdle to overcome, requiring information and awareness campaigns to reassure consumers about the quality and safety of reused water.
Information panels in public spaces using treated wastewater can also help to inform the public.
REUT regulations and opportunities for treated wastewater aim to optimize wastewater management and encourage its reuse in various sectors.
TheAugust 2, 2010 REUTdecree lays down the basis for using water from urban wastewater treatment plants to irrigate crops or green spaces.
In 2014, thedecree of June 25, 2014 amended the decree of August 2, 2010 on the use of water from urban wastewater treatment for agriculture or green spaces.
Then decree no. 2022-336 of March 10, 2022 on the uses and conditions for reusing treated wastewater was issued.
The REUSE decree, in line with the Water Plan presented by the French President on March 30, 2023, aims to promote the reuse of water to meet the growing challenges linked to the management of water resources in France. The aim is to promote the use of treated wastewater, particularly for agricultural irrigation, industrial and urban uses, in order to meet the challenges posed by water shortages and climate change.
With a view to driving the transition to a circular water economy, while emphasizing the protection of public health, a significant legislative breakthrough has been initiated by influential members of the French government. Christophe Béchu, at the head of the Ministry of Ecological Transition and Territorial Cohesion, and his counterparts, Aurélien Rousseau in charge of Health and Prevention, Agnès Firmin Le Bodo, responsible for Territorial Organization and Health Professions, and Sarah El Haïry, dedicated to Biodiversity, have joined forces to promulgate Decree no. 2023-835 of August 29, 2023 on the uses and conditions of use of rainwater and treated wastewater. This evolution of the legislative text by government ministers aims to simplify the administrative procedures associated with the reuse of treated wastewater (REUT), a visionary measure for the environment and the well-being of citizens.
Thedecree of December 14, 2023 relates to the conditions for the production and use of treated wastewater for watering green spaces. A new decree dated December 28, 2023 specifies quality thresholds for treated wastewater reut according to use and crops, allowing the use of lower quality water with additional safety measures.
These regulations offer opportunities to improve water conservation efforts and help farmers access safe water sources for crop irrigation.
The publication of REUSE decree no. 2024-33 of January 24, 2024 establishes specific standards for the use of treated water in the food sector, thus guaranteeing public health.
The aim is to establish specific standards and practices for the use of treated water, allowing some recycled water to be used as an ingredient in food production. To obtain authorization for production and use, a dossier must be submitted to the prefect with detailed information and an assessment of health and environmental risks.
The quality of treated wastewater is monitored by both the production plant and the utilization plant, with reinforced monitoring during the first two years of authorization. These measures ensure that reused water complies with the most stringent health standards.
Reused water can be classified according to its quality and intended use, such as irrigation or industrial applications. The quality of reused water is classified into four categories according to the reut treated wastewater decree: A, B, C and D, based on analytical parameters.
Authorized uses exclude certain domestic and amenity uses, to guarantee health safety.
Filtration technologies are essential for treating wastewater prior to reuse. They remove impurities and contaminants, thus ensuring the quality of the reused water. Filtration systems include coarse, granular and membrane filtration, each designed to remove different types of contaminants.
These technologies play a decisive role in wastewater treatment, making water safe for a variety of uses.
Coarse filtration is used to remove large particles from wastewater prior to the finer treatment stages. This technology generally uses screens or sieves to remove suspended solids.
Coarse filtration systems are essential to prepare water for more advanced treatments.
Granular filtration uses sand filters for more advanced water clarification. Granular filters can be multi-layered, combining different materials for greater suspended matter retention capacity.
This type of filtration is particularly effective at removing small suspended solids and organic impurities.
Membrane filtration removes suspended solids without turbidity as well as some bacteria and viruses. This method can retain beneficial nutrients or eliminate microalgae depending on the specific needs of water reuse.
The membranes used are capable of filtering out micropollutants such as viruses and bacteria, ensuring high-quality water.
The reuse of wastewater helps to reduce groundwater abstraction, particularly in coastal areas. This practice helps to maintain satisfactory groundwater levels, thus avoiding the deterioration of groundwater. In times of drought, treated wastewater can be used to recharge groundwater, offering a sustainable solution for water management.
To integrate wastewater reuse into groundwater management, it is essential to improve water treatment at wastewater treatment plants (WWTPs). This strategy conserves water resources, reduces demand for fresh water and cuts the costs associated with treatment and distribution.
The reuse of treated wastewater helps reduce global water stress, which currently affects over 40% of the population. By maintaining a satisfactory level of groundwater, this practice protects groundwater. It contributes to the conservation of natural resources and adaptation to climate change.
Compared with seawater desalination, wastewater reuse is a greener, less polluting option.
To integrate wastewater reuse into groundwater management, effective implementation strategies are needed. This includes improving treatment processes at wastewater treatment plants and adopting sustainable practices.
Treated wastewater can also be discharged into coastal areas without risk to the environment, offering a more sustainable management method than seawater desalination.
In France, less than 1% of wastewater is recycled, but the situation is different in other countries such as Israel (90%) and Spain (14%). Climate change and population growth are forcing us to review water management models to ensure sustainable access. Reusing treated wastewater is part of the circular economy, optimizing water flows from design to end-of-life.
The challenges of wastewater reuse include managing public perceptions and implementing strict regulations. However, the outlook is promising, with initiatives aiming to increase the volume of recycled wastewater by a factor of six over the next few years.
Treated wastewater can contain pathogenic micro-organisms and potentially toxic organic and inorganic chemicals. Regular monitoring and control of treated wastewater is essential to ensure its safety.
Public health is therefore a major issue in wastewater reuse, requiring rigorous measures to protect consumers.
The outlook for wastewater reuse is encouraging. The European Commission is aiming for a six-fold increase in the volume of recycled wastewater to reduce pressure on water resources. This initiative is in line with the objectives of the European Green Deal, supporting more sustainable and efficient water management.
The REUSE decree imposes strict standards for monitoring and managing water flows to guarantee the safety and efficiency of reuse practices. Ultrasonic flowmeters are essential tools in this context. Thanks to their ability to accurately measure flow rates without direct contact with the liquid, they enable continuous, reliable monitoring of reused water volumes. Their easy installation and low maintenance requirements make them ideal for water treatment plants.
These flowmeters provide real-time data, facilitating informed decision-making and optimization of reuse systems. By integrating ultrasonic flowmeter technology into water management systems, companies can meet regulatory obligations while improving operational efficiency and environmental sustainability.
Non-intrusive ultrasonic flowmeters use transit time ultrasonic signal technology to measure industrial wastewater flow on any size of pipe. These water meters provide accurate flow measurement for real-time monitoring of water consumption. With IP64 protection, these devices are resistant to dust and splashing water, ensuring safe, reliable measurement of water flows.
Ultrasonic flowmeters can measure the flow of drinking water supplies, wastewater treatment plants, and irrigation systems. Clamp-on transducers offer easy installation and exceptional flexibility for a variety of agricultural applications.
Fixed-mount ultrasonic flowmeters, such as Fuji Electric's Time Delta-C flowmeter, offer exceptional adaptability to a variety of industrial systems, with pipe diameters ranging from 13 to 6000 mm. These devices are ideal for urban water resource management, enabling accurate and reliable flow measurement, essential for optimizing water use in urban environments.
Non-intrusive clamp-on ultrasonic flowmeters offer numerous advantages for measuring and monitoring the flow of drinking water. The benefits of ultrasonic flowmeters include the absence of pipe cutting and the absence of risk of fluid contamination.
Their use guarantees water quality and consumer safety.
Wastewater reuse is a promising solution to the world's water management challenges. From industrial uses to agricultural irrigation, urban applications and drinking water, this practice offers considerable economic, environmental and health benefits. The development of advanced treatment and filtration technologies, combined with stringent regulations and precise measuring devices such as ultrasonic flowmeters, ensure the safety of water quality and the efficiency of wastewater reuse.
By adopting these practices in France, we can reduce our dependence on fresh water, protect natural resources and guarantee a sustainable future. Wastewater recycling is not only a necessity, but also an opportunity to rethink our water management and build a more resilient, environmentally-friendly world.
