Will we be drinking recycled water in the future?

With the increased frequency of droughts and heightened water stress almost everywhere worldwide the reuse of processed wastewater would seem to be a way forward. From industries to the countryside and including tap water, the precious liquid is increasingly recycled.

For many people, the idea of drinking water that has been recycled from our toilets, showers and washing machines, among others, does not seem very appealing.

And yet, in certain parts of the world suffering from serious water stress, quality drinking water is already produced from filtered and treated wastewater. In Namibia for over 50 years, in Australia, California, Texas,  Singapore... And tomorrow in France? There is nothing extravagant about the concept when you learn that during the summer of 2020, drought broke a record in France and 86 departments experienced difficulties with the supply of drinking water or had to restrict the irrigation of farmlands. One year earlier, a tributary of the Dordogne river had dried up, forcing many villages in the Corrèze region to use tankers to bring in water.

With the rapid growth of the world’s population, the increase in urbanisation and climate change, the lack of what is known as “blue gold” has become a challenge worldwide. This is even more the case in a period of pandemic, when access to freshwater is vital to ensure the conditions of hygiene required to prevent the illness, but not always guaranteed for the most vulnerable.

How can we reduce the pressure on freshwater resources?

A solution that is underexploited in France

The situation explains why experiments linked to recycling water have blossomed in recent years. A golf course has been irrigated in Istres (Bouches-du-Rhône), green areas have been watered in Sainte-Maxime (Var), and urban purification pipes have been cleaned in Deauville (Calvados)... Reusing treated wastewater – or reuse – is complementary with optimising consumption and fighting waste and does not just concern drinking water.

Still in its infancy in France, reuse represents less than 1% of all forms of consumption of water (against 14% in Spain or as much as 80% in Israel). But things could change if droughts continue to become more frequent. “With the appearance of areas of water stress, certain municipal authorities are beginning to think about the resilience of their infrastructures and water supply. They say, justifiably, that wastewater is a resource that is currently underexploited,” remarks Arnaud Valleteau de Moulliac, Managing Director of OTV, Veolia’s French subsidiary specialising in the design and integration of water treatment technologies. In certain areas of the world affected by water stress, investing in this type of solution has even become a prerequisite for industrialists. “It’s also an acceptance issue for local populations, who are seeing their groundwater disappearing,” points out Arnaud Valleteau de Moulliac taking the case of Nestlé, who asked Veolia to set up a babies’ powdered milk production centre with “zero water consumption” in Mexico, in South Africa and China. This solution introduced by the Group enables factories to reuse the water contained in dairy cows’ milk, which is dehydrated to produce powdered milk.

 “With the appearance of areas of water stress, certain municipal authorities are beginning to think about the resilience of their infrastructures and water supply..."


Why take water from its natural environment to irrigate a field or cool industrial installations when we have wastewater nearby that can be purified? In the case of farming, which represents 70% of freshwater consumption across the planet, according to the OECD, the presence of certain elements in water, such as phosphorus and nitrogen which are widely used fertilisers, is even welcomed. “When we treat wastewater, we always ask what use it will be put to in order to increase the amount of such and such an element it contains, ” explains OTV’s Managing Director. In the Hautes-Pyrénées area, Veolia’s SmartFertiReuse project is experimenting with the irrigation of farmlands using treated wastewater enriched in nutrients. Its smart management system enables the production of controlled quality water that meets plants’ nutrition requirements.


Would you like another beer based on recycled water?

One thing is certain: that the techniques are ready. “Today, we are capable of producing drinking water in purification stations and we have all the tools to pilot and monitor its quality. We can even make ‘ultrapure’ water for the micro-electronics or pharmaceutical industries, solely with H2O molecules,” says Arnaud Valleteau de Moulliac. The Group has developed hundreds of proprietary technologies, from refining by filtration to the elimination of micropollutants including the microplastics found in drinking water. This is notably due to a membrane separation technique or an extremely fine synthetic membrane, which acts as a filter retaining particles and pollutants.

He adds: “The challenges involved with reuse are no longer technological but regulatory (in France, the reuse of treated wastewater to produce drinking water is not authorised and is also subject to various criteria for uses in farming [Ed.]) and social acceptance” – a psychological obstacle also known as “the yuck factor”. On this point, the concerns linked to the availability of freshwater could lead mentalities to evolve. According to an Elabe survey carried out for La Tribune newspaper in 2020, a majority of French people (83%) would be prepared to drink water produced from wastewater. To counter the stigmatisation of reuse, the Czechs, meanwhile, had the idea of beginning to produce brewed beer from recycled water (it takes some five litres of water to make one litre of beer).

Tripling volumes by 2025

Little by little, as experiments increase, so the idea is gaining ground. A pioneer in France, La Vendée, on the west coast, has launched a project to produce drinking water from the wastewater from the local purification station, near Sables-d’Olonne. As of 2022, instead of being thrown into the sea, the purified wastewater will be given a complementary treatment to feed a dam where a drinking water factory captures the resource. 

Another idea that could be explored in France in the future is to artificially replenish groundwater with treated wastewater (which could also produce drinking water, but indirectly). The latest Anses report to date in 2016, is in favour of this on condition that it is tightly controlled in order to control health risks.  Elsewhere in Europe, notably in Belgium (Wulpen) and Italy (Nardò), this is authorised as part of the experiments to allow for the study of health and environmental impacts over the longer term.

The wastewater issue is now being played out on the political stage. In 2019, a Water Conference (Les Assises de l’Eau) envisaged the tripling of so-called non-conventional water (including treated wastewater) by 2025. Similarly on a European level, new legislation adopted last May plans to encourage the reuse of wastewater while defining requirements for a minimum quality throughout the European Union.  The ambitions are substantial: “Potentially, we could reuse 6.6 billion m3 of water by 2025, as against 1.1 billion every year at the moment,” according to the European MP in charge, Simona Bonafè. “That would require an investment of under €700 million and would enable us to reuse more than half of the current volume in wastewater treatment stations theoretically available for irrigation.”


This will relieve some of the pressure on the resource and treat ‘blue gold’ at its true value.

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