In France, many departments affected by drought are currently facing restrictions on water use. And tensions are increasing, as evidenced by the recent degradation of large reserves – “basins” – in the Vendée.
The situation is similar at European level. “It is our duty to stop wasting water and use this resource more efficiently,” warned EU Environment Commissioner Virginijus Sinkevicius on August 3, giving advice to member states on how to better reuse water in the agricultural sector. One of its priorities is the reuse of treated wastewater (Reut or Reuse in English).
1. What is this?
Wastewater is intended to be discharged after industrial or domestic use, which has caused it to lose its original purity. To eliminate unwanted chemical and biological contaminants, they are treated in a sewage treatment plant before typically being discharged into the natural environment.
However, they could be reused for four different purposes that would save drinking water, the Water Information Center notes: agricultural irrigation, community use, purification for industry, and groundwater recharge, which is the main reservoir of drinking water.
2. Which countries are at the top?
At present, the market for the reuse of treated wastewater worldwide is mainly driven by Asia – especially China – as well as the United States for industrial use and the Middle East for industrial use, according to Yvan Poussade, International Manager for this topic at Veolia , the French Giants in water and waste management. Israel already reuses 90% of it.
In Europe, it was the countries around the Mediterranean, facing situations of pronounced water scarcity and significant agricultural needs before France, that had taken the lead. Cyprus reinstates them at 20%, Spain at 14%, Italy at 8%.
In 2020, the European Union (EU) adopted a regulation, effective from June 2023, which aims to facilitate reuts, particularly for agricultural irrigation (excluding green areas), while harmonizing the rules applicable in all Member States. According to the European Commission, more than 40 billion m³ of waste water are treated in the EU every year, but only 964 million m³ are reused.
3. Where is France?
Since the initiative on the island of Noirmoutier (Vendée), several experimental projects have been launched across France. From irrigated green spaces in Sainte-Maxime (Var), to a drip fed by this treated wastewater, to their reuse to clean urban sewage pipes in Deauville (Calvados), via Disneyland Paris. Even with manufacturers like Cooperl, who recycle a large part of it in their Breton slaughterhouses.
But France is lagging behind: Less than 1% of the water coming out of its 22,000 treatment plants is reused, in initiatives that are still mostly for agricultural and golf course irrigation, and often for seasonal purposes. The regulations, in force since 2010 and revised in 2014, regulate reprocessing and reuse in order to protect public health and the environment. Even if the industrialists in the branch judge it “dramatic” compared to its European neighbors.
“For two years we have been seeing the arrival of many municipalities that want to set up Reut solutions on their territory, but they do not necessarily recognize the time required to compile this type of file for which permit requests take several months or even years to complete to be successful in France”, assures Yvan Poussade. The European framework should allow harmonization.
4. What do the regulations say?
French regulations define four levels of hygienic quality of treated water, depending on the intended use: A (for irrigating gardens, pastures, green spaces open to the public), B, C (for irrigating woody areas) and D. “Any coastal cities facing resource or drought problems should consider this solution for anything other than potable water. believes Yvan Poussade. But the projects should not be at the expense of the environment and waterways in summer. »
In 2019, the Assises de l’Eau aimed to triple the amount of unconventional water reused by 2025. In March 2022, as part of the Anti-Waste Law for a Circular Economy, the government approved “on an experimental basis new uses of treated wastewater previously banned, particularly for urban purposes” : street washing, hydro-cleaning of networks, but also groundwater recharge.
The Jourdain demonstration project could also play a role “a first in Europe”, according to its promoters: Inspired by countries with water shortages like Namibia, it will ensure the drinking water supply for the inhabitants of the Vendée in the coming years thanks to a refinery plant under construction in Les Sables-d ‘Olonne.
also read : Converting waste water into drinking water: a first in Europe in Les Sables-d’Olonne
5. What are the brakes?
The current brakes have several orders. Financially of course. Indeed, in order to be reused, the treated wastewater must undergo additional treatments and therefore becomes more expensive depending on the quality required for its end use. This requires dedicated infrastructure, not to mention the cost of new pipes. Much infrastructure funding can be supported by European or local grants. Operating costs remain high.
“Compared to abstraction from the natural environment, for which farmers and irrigation companies pay a fee in the range of 1 to 3 cents per m3 and then have transport and pumping costs to their irrigation system, we are potentially five times more expensive than a Reut- Solution “ , recognizes Yvan Poussade. He thinks he “We must not think of financial benefits, but of the sustainability of the activity”.
The key to success is collectively, if we are to believe a 2014 study by Onema and Irstea, which refers to French projects that generate strong economic returns for communities. They all have in common the physical proximity to the sewage treatment plant and potential major users, the existence of connections between the providers of the Reut services and the users, as well as long reflection beforehand.
The population’s concerns about these “grey waters” must also be addressed. French players in the sector have “technical mastery and sophisticated sanitary water management procedures and all that is necessary to ensure that this risk is controlled: it is no more risky on arrival than other types of water for the uses contemplated” , assures Yvan Poussade.
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