Jourdain program

Securing the supply of drinking water

Even if the experiment is carried out at one quarter of the flow rate of the eventual full-scale solution, the program will already allow an additional supply of water into the Jaunay reservoir. When the refining unit is built, it will supply the reservoir with the equivalent of the drinking water consumption of 25,000 Vendéens per day and operating all year round, the volume reinjected will be 960,000 m3/year.

The full wastewater reuse solution, to be implemented thanks to the demonstrator, will provide drinking water for the equivalent of 75,000 people per day by recharging the Jaunay reservoir with 3.8 million m3 per year of water.

The treated wastewater introduced into the lake will only be used for drinking water purposes because no other withdrawals (e.g. for agricultural irrigation) are made from the resource

Preserving the natural environment ?

The water is not treated and reinjected in order to be able to increase withdrawals for drinking water but only to secure them, especially in times of drought. It will therefore make it possible to replace a share of the volumes withdrawn from the environment to preserve a greater quantity of water for the natural environment and participate in the support of the environmental water needs of the river.

The Jordan program will also promote biodiversity in the vegetated transition zone, which is designed to create a gentle connection between the discharge of treated water and the Jaunay reservoir. Through ponds and vegetated meanders, the area will contain a great diversity of habitats.

Improving the knowledge and state-of-the-art reuse practices

To be able to implement sustainable reuse projects, the benefits of the demonstrator are essential. Indeed, the Jourdain program is composed of several activities that generate concrete data from an innovative and unprecedented project in France and Europe. The studies carried out cover very broad areas for reuse applications, such as water treatment and analytical techniques, governance, communication, modelling, and social and economic aspects. The results of the in-situ experiment will contribute to advancing knowledge and state-of-the-art reuse practices.

Influence the regulatory framework and promote replication

The provision and sharing of the knowledge and feedback acquired during the program will help to influence the regulatory framework around this theme and to encourage other territories to replicate this solution. The Jourdain demonstrator is a model that highlights (and aims to validate) water reuse for drinking water. In France the development of this type of project is envisaged in many regions as one solution in the face of the current or impending water deficits.

For example, in the Vendée, the water reuse potential of coastal resorts represents a volume of 4 to 6 million m3 (the equivalent of the main reservoirs in the north-west such as the Jaunay or Apremont).

Supporting innovation

Beyond the benefits specifically related to state-of-the-art reuse practices and the replication of the project, the demonstrator aims to be a support for innovation. Complementary to the innovative nature of the reuse project itself, the Jourdain program allows, for different subjects, to design, adapt and optimize solutions within the framework of a reuse loop and to contribute to scientific and technological advances. This approach, called Open Demonstrator, can take different forms (partnerships, research projects, call for expressions of interest, etc.) and affects all the themes encountered.

Strengthening the acceptability of water reuse

As the demonstrator is in-situ and governed openly, it is subject to public opinion and reaction. Communication, pedagogical and social actions are therefore carried out to strengthen the acceptability of water reuse and to create a local and territorial dynamic. These actions will be undertaken at the level of citizens and water stakeholders, on the subjects of good practices in resource management and the circular water economy, with the aim of developing a sustainable solution beyond the demonstration phase.

The health authorities (Regional Health Agency of Pays de la Loire – Vendée delegation – ARS85) and environmental authorities (Departmental Directorate of Territories and the Sea of Vendée – DDTM 85) have been supporting Vendée Eau since 2014 in the regulatory framework, the preparation of authorization application files and the implementation of specific regulatory monitoring. In 2016, ANSES (Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail) produced a scoping note intended to provide the guidelines for such a project, particularly in terms of analytical monitoring to be implemented.

In the absence of a specific regulatory framework and in order to answer all health and environmental questions, the decision was taken in 2014 to create a demonstrator at a quarter of the available flow, before a potential transition to full scale. This demonstrator, called the Jordan program, will be strictly supervised. During the first year, the performance of the treatment unit will be evaluated with discharge into the ocean. Evaluation will continue throughout the demonstrator period to measure the in situ effects of treated water reinjection. The DDTM85 and ARS85 produced a regulatory framework note in 2017, updated in December 2020 and February 2023, which provides all the steps to be taken at different levels.