There are more than a hundred thermal establishments in France, distributed mainly in the South-West and the South-East. Together, they welcomed nearly 550,000 spa guests in 2021, according to the Ministry of Health. Many brands, like Avene Or Jonzac Water, also use these thermal waters in their sprays, creams, treatments, etc. So, fans of hot water cures with beneficial properties or addicts to thermal water-based creams, rest easy.
These resources, considered on the regulatory level as mineral waters, are far from being in danger, despite the drought that has been raging since this winter. For what ? Because, on the one hand, “thermal waters are collected from underground water tables, generally very deep, from 100 to several thousand meters deep depending on the case”, says Patrick Lachassagne, director of the HydroSciences research laboratory in Montpellier.
“Treatment to our curists for many more years”
And because, on the other hand, these waters are slow to show up. On the sampling site of Avène, in the Haut Languedoc, the infiltration of rainwater through the rocks takes, for example, fifty to 200 years before being transformed into thermal water. “To date, it is therefore difficult to see an impact of the drought of 2022 and 2023 because there is no immediacy effect. Also, we have no doubt that we will still be able to offer treatments to our spa guests for many more years,” admits Sophie Mery, director of the Avène thermal center. this without taking into account that the volumes sampled are low, according to the director of the HydroSciences laboratory: “natural mineral water is a very small sector. Production for hydrotherapy, which initially must be characterized as natural mineral water, has no negative impact (on the resource). »
“The volumes of thermal water used for thermal treatments and the manufacture of dermo-cosmetic products is well below the level of natural renewal of the thermal water resource by rainfall and, it should be added that our activity is seasonal, it stops for more than four months each year, which contributes to the refilling of the thermal reservoir”, abounds Sophie Mery.
Same story, on the side of Jonzac where the source is not about to dry up and drought is not even a subject. “According to the city of Jonzac, this aquifer is not influenced by the current climate”, soberly replied to 20 minutes the communications department of Léa Nature, owner of Eau Thermale Jonzac, located in Charente-Maritime.
Waters under “close surveillance”
Stable from the point of view of their physico-chemical characteristics, the thermal waters are nevertheless closely monitored. Both by the operators of the different brands and the regional health agency (ARS). “The mineral composition of thermal water is closely monitored with almost daily checks to guarantee the quality and regularity of its mineral composition”, explains the director of Avène. Temperature, pH, conductivity, bicarbonate, magnesium, calcium, nitrate and microbiological parameters are regularly scrutinized by the control authority. “In 2022, there were no quality or quantity problems with water bottling plants in New Aquitaine. And in 2023, we are still not aware of any problems, ”notes ARS Nouvelle-Aquitaine again.
Most thermal waters are drinkable but the establishments do not have to comply with any drinking water requirements, as is the case for mineral waters intended for consumption. “In theory, we could make the thermal water drinkable, but its supply would be very complicated because the springs are not necessarily located in areas with population pools”, analyzes Patrick Lachassagne. And the hydrogeologist to specify: “on the Mediterranean rim, where certain communes lack water, there are no thermal waters nearby. And these represent such small volumes that they could not meet the needs (in drinking water). »