Saint-Gervais Mont Blanc Thermal Water

Healing Properties & Our Commitment to Excellence

The Remarkable Origins of Our Thermal Water

A Millennia-Old Journey

In 2017, we received truly remarkable news… We were able to precisely determine the age of Saint-Gervais Mont Blanc thermal water. Thanks to carbon-14 dating, it was revealed that 6,500 years separate the rainfall that fell on the Alpine peaks from the moment the water springs forth at 39°C!

Naturally Enriched with Minerals and Trace Elements

As it travels through the rocks, the thermal water absorbs a wealth of minerals and trace elements: sulphur, boron, silicon, manganese, strontium, lithium… It is 30 times more mineralised than ordinary drinking water, containing around 4,000 mg of minerals per litre. Due to this high mineral content, the water is non-potable and can only be consumed under medical prescription.

Thermal Water with Multiple Benefits

Used since 1806 and officially recognised by the French Academy of Medicine since 1996, it offers proven benefits in dermatology, respiratory care, wellness, and cosmetic products. Children and adults alike—whether spa guests or visitors—can enjoy its restorative, healing, soothing, anti-inflammatory, and decongestant properties.

Our Dedication to Quality, Safety, and Excellence

Purity and Control of Our Thermal Water

Protected from any external infiltration, the thermal water of Saint-Gervais Mont Blanc is drawn from a depth of 101 metres, retaining all its exceptional properties.

To preserve its natural qualities, the extraction and use of this water within the Saint-Gervais Mont Blanc thermal centre are subject to rigorous controls. The Thermes strictly adhere to French standards for thermal spa care.

Certifications and Standards

The Thermes have been Aquacert certified since 2013, a mark of excellence, transparency, and quality of Mont Blanc thermal water.

This certification process ensures that the exploitation of the thermal water meets the highest standards of safety and optimal use. Aquacert is internationally recognised, developed and awarded by independent organisations and scientific experts.

The Thermes have implemented comprehensive monitoring procedures, from the source all the way to the spa facilities. The on-site control laboratory monitors the quality and stability of the water’s composition, as well as the bacteriological cleanliness of the establishment. Numerous tests are carried out throughout the year to guarantee safe and healthy water, including:

Water testing at the spring emergence
Water monitoring across the various spa services
Systematic disinfection of the thermal water distribution network using advanced technology adapted from the food industry, provided by Tetra Pak
Bacteriological testing of floors and surfaces
Monthly analyses by an accredited laboratory to ensure compliance and water quality tracking

The purity of thermal water is a crucial factor in the effectiveness of spa treatments. At the Thermes de Saint-Gervais, stringent processes ensure the water remains free from contamination, untreated in the medical section, with quality controlled at every stage of its utilisation.

In 2025, the Thermes de Saint-Gervais achieved an outstanding Aquacert rating of 98%. This demonstrates that, since initiating this project, the team has successfully guaranteed optimal quality by continuously enhancing the control processes of Mont Blanc thermal water.

Environmental Commitment

For several years, the Thermes de Saint-Gervais have invested in a geothermal system with centralised digital management. This system heats the entire building and maintains a constant temperature in indoor and outdoor pools.

It also provides spa guests with a comfortable and consistent temperature and humidity, while preventing the release of approximately 200 tonnes of CO₂ into the atmosphere.