Will we soon learn more about the possible failures of the French authorities in the scandal of mineral waters illegally processed by Nestlé? This Tuesday, during a meeting of experts within the premises of the European Commission, representatives of the Ministry of Health presented an overview of the issue of these waters supposed to be “pure”. Contrary to what is required by the European directive on natural mineral waters, France did not warn Brussels of non-compliant practices by Nestlé even though it had been aware of it since 2020.
At the same time, the controversy continues to mount. Last week, Nestlé announced that it had destroyed two million bottles of one of its flagship brands, Perrier water. By means of a decree dated April 19, the multinational was in fact ordered by the prefect of Gard, the department where the sparkling water is pumped, to “suspend without delay” the exploitation of the Romaine VIII drilling, located in the commune of Uchaud – bottling takes place on the neighboring site of Vergèse. The cause is contamination of fecal origin probably caused by the heavy rains that occurred at the beginning of March. Sophie Ressouche, head of the groundwater division of the Vistre Vistrenque Territorial Public Basin Establishment (EPTB), responsible for managing the resource in the area where Perrier pumps, explains why the aquifer in question is vulnerable to bacterial pollution.
What are the characteristics of the water table into which Perrier water is pumped?
Nestlé exploits the limestone layers of the Nîmes scrublands, made up of hard rocks dating from the Cretaceous period and crossed by cracks filled with water. This fairly vast hydrogeological system extends along the Nîmes fault and even goes beyond the limits of the Gard department, as far as Hérault. These are compartmentalized tablecloths. In the Nîmes sector, the Nîmes fountain, a historic Source, constitutes the main outlet of the system. Part of this reservoir is located “undercover” : more recent deposits cover the deep limestone rock. We lack information on the age of the water that circulates, we just know that, in the deepest areas, it is very old. Nestlé has launched a study to improve knowledge of this reservoir and its supply method. This system communicates with the Vistrenque and Costière water tables, made up of sand, gravel and pebbles whose interstices fill with water.
What does a catchment on this aquifer operated by Perrier look like?
A borehole in a water table, much more impressive than a private well, is like a hole into which a metal tube is inserted and into which a pump slides. The diameter is sometimes such that we can penetrate certain catchments.
Is this tablecloth used for purposes other than those of Nestlé?
Yes, the limestone aquifer from the Nîmes scrublands is used to produce tap water but not necessarily in the same compartment as that operated by Nestlé. Two Gard communes are supplied by this same aquifer. Their water does not fizz because the gas is only present in the water at great depths along the Nîmes fault.
Was the contamination with fecal matter at the beginning of March spotted elsewhere on the water table than in the Nestlé drilling?
Not to my knowledge. But even in the event of occasional bacterial pollution, a community can treat drinking water before distributing it. A chlorine-based treatment eliminates bacteria and viruses. On the other hand, after the heavy rains in March, the water became much murkier in other areas than the limestone scrublands of Nîmes. However, suspended matter is conducive to the development of bacteria. In this case, the inhabitants can be supplied by means of other boreholes. On the other hand, for natural mineral waters, such as those produced by Nestlé, purification treatments are not authorized. Water must be naturally drinkable before being bottled.
The contaminated Perrier catchment plunges more than 100 meters into the basement. Is it surprising to find bacteria at such a depth?
No. Due to its configuration, the water table is vulnerable to this type of pollution. This is the case for all karst systems. [constitués de calcaire, ndlr]. In the event of heavy rains, there may be leaching of the soil and this could lead to fecal pollution from excrement and wastewater. In limestone systems, water penetrates and circulates very quickly; the environments crossed do not act as natural filters. In a system like the Vistrenque aquifer present in the plain, which is like a sponge made up of pebbles, sand and gravel, we have much fewer bacteriological problems because the material which constitutes the water reservoir plays the role of filter.
In collaboration with Nestlé, you are working with farmers so that they use fewer pesticides. Is the water table also vulnerable to chemical pollution?
Yes. We work to protect the quality of water around catchments which can be degraded, in particular because of problems of diffuse nitrate or pesticide pollution. We are implementing, with Nestlé, joint actions to preserve underground resources. The limestone aquifer, however, has fewer problems linked to this type of chemical pollution because the scrubland sector is a natural area of scrubland, oaks and pines, less cultivated than the plain.
Can climate change increase problems?
It especially has a quantitative impact on the water tables, which recharge less well due to the lack of rain in winter. In terms of quality, there may be an impact on diffuse pollution, particularly nitrates. If there is less water, these pollutants are less diluted.
A new Cévennes episode is expected in the area this week. Should we fear a new episode of leaching and contamination of the water table?
Not really because the precipitation expected this week has nothing to do with that of two months ago. Between 40 and 60 mm of rain are forecast, while in March we had more than 200 mm, which was exceptional. There is no necessarily reason to worry about the days to come.
