The SEDIF project is not viable from the point of view of European water policy either. On Tuesday 18 July, the European Parliament's Petitions Committee gave urgent consideration to a petition initiated by our association and took a series of measures to support it. This successful action concludes our campaign as part of the public debate which ends on 20 July, and opens up a new direction for our fight over the coming months. Update of 20 July: the Chair of the Petitions Committee, Ms Dolors Montserrat, has acknowledged the admissibility of the petition and the action taken (letter to be downloaded below).

Update of 20 July: Download the letter from the Chair of the Petitions Committee.

With several co-signatories, we filed a petition with the European Parliament's Committee on Petitions on 12 May 2023. It is registered under number 0478/2023 (it must appear on the European Parliament's website within four months of submission).

On Tuesday 18 July, the European Parliament's Committee on Petitions held an urgent examination of the petition concerning the Syndicat des Eaux d'Île-de-France's plan to use low-pressure reverse osmosis (LPRO) to treat drinking water.


Download the petition with the first signatories

The petition was presented by Jean-Claude Oliva (see his speech below). In his response, the European Commission representative requested that the French authorities carry out environmental assessments of the impact of the SEDIF project on water bodies and Natura 2000 areas downstream of the SEDIF plants; his detailed written opinion will be published in the next few days. The EPP (right), Socialist and Ecologist groups gave their support to the petition, asking that it remain open on the European Parliament website and that the matter be referred to the European Union's Environment Committee. Following the hearing, a letter from the Petitions Committee will be sent to the French authorities within two weeks.

Watch the video of the hearing (dubbed in English) from 10:10:30 onwards

Preliminary remarks by Jean-Claude Oliva

Members of Parliament, Ladies and Gentlemen,

First of all, I would like to thank you for putting our petition on your agenda.


The Syndicat des Eaux d'Ile-de-France (SEDIF) is a public body responsible for drinking water, which outsources this service to Véolia. Its network serves four million users out of the twelve million inhabitants of the Ile-de-France region.

SEDIF wants to introduce a new water treatment process at its three main drinking water production plants in response to the following problems: the presence of micropollutants in drinking water, the chlorination of water for transport and the presence of limescale.

The project involves extending membrane filtration based on Low Pressure Reverse Osmosis (LPRO), an equivalent process for freshwater, to the desalination of seawater. Desalination of seawater produces fresh water and brine; LPRO on fresh water produces demineralised water, which is not drinkable in its current state, and a concentrate of mineral salts and micropollutants. The osmosis water would be mixed with nanofiltered water (a membrane filtration process that allows mineral salts but also certain micropollutants to pass through) to become drinkable.

I'm not opposed to technological innovation in general, nor to this process in particular. It can be useful on a local scale or on a temporary basis, when there is no other option. But extending it to the SEDIF area initially, and then potentially to the whole of the Île-de-France and other regions, would have major drawbacks for the environment and harmful social impacts because of its disproportionate cost.

One of the main challenges of the project relates to the concentrate of mineral salts and micropollutants produced as a result of membrane filtration. More than 100,000 m3/day of concentrates (up to 140,000 m3/d) will be discharged directly into waterways (the Seine and its tributaries the Marne and the Oise). The SEDIF has acknowledged that such waste would be discharged into watercourses.

Locally, at the discharge points, significant direct impacts on flora and fauna are to be expected.

The same concentrates would then be discharged into the water catchments and alluvial aquifers that supply the inhabitants of western Paris, causing degradation of surface water bodies and ecological impacts on Natura 2000 classified areas downstream of the SEDIF plants.

This goes against the intention of the Water Framework Directive. In fact, the SEDIF's project is degrading the quality of water bodies by pushing the degree of water purification beyond accepted standards; it is forcing downstream drinking water treatment plants to step up their treatment as well, because the water withdrawn will be more polluted. It is this break with the principle of upstream-downstream solidarity that led my colleague Dan Lert, President of Eau de Paris, to co-sign this petition.

In addition to the direct consequences for the plants located downstream of those of the SEDIF, this project aims to build a technological showcase for the membrane filtration process on a Ile-de-France, national and European scale. Indeed, the arguments used to promote the project systematically devalue and disqualify other water treatment processes (such as activated carbon with continuous renewal), which are just as efficient and do not have the same environmental drawbacks. Its adoption by France's largest public water utility would give it a high profile, and could encourage many towns and cities to follow suit. It would be a major selling point for the companies that mastered it, to offer it everywhere. This danger of seeing membrane filtration imposed everywhere, indiscriminately, with a purely commercial aim, led my colleague Philippe Rio, chairman of the Grand Paris Sud public water company, to co-sign the petition.

Moreover, the SEDIF is delivering an alarmist message about the quality of the water currently being distributed, implying that it is undrinkable, that prevention is and always will be a failure and that the only solution is to increase treatment. An exclusively curative approach to drinking water quality is being promoted.

Priority is given to health issues over environmental issues, ignoring the fact that our health ultimately depends on the state of the environment.

This project therefore runs counter to the precautionary principle. Yet the SEDIF justifies the need for the LPRO by the application of the 2020/60 drinking water directive and even claims to anticipate future European standards. Yet the water currently distributed by SEDIF already complies with all the parameters of the Drinking Water Directive, without the use of LPRO!

Membrane filtration treatment is presented as a miracle recipe that would dispense with all efforts to limit environmental pollution by pesticides. It's a licence to pollute. Unlike other treatments, it retains micropollutants in the environment via the discharge of concentrates. Alternatives exist in the form of processes such as continuously renewed activated carbon, which removes micropollutants from the water and destroys them.

For all these reasons, we have referred this matter to your committee, and I would like to thank you for your attention.

Read the article originally published on the Eau Île-de-France website on 19.07.2023 here. (in French)