Le Plongeoir Newsletter (Substack) — “Plongeon Portrait” sponsored content, paid partnership · June 20, 2025 · Article by Guillaume Fourdinier
In a “Portrait Dive” feature in his newsletter *Le Plongeoir*, Guillaume Fourdinier traces the journey of Castalie, a French pioneer in microfiltered water. The article places the company within the context of a bottled water model that is running out of steam—poorly recycled plastic, emerging pollutants, and consumer mistrust. The company’s founding story, technological choices, and growth trajectory paint a picture of a local, circular alternative to plastic bottles.
Key takeaways
- Castalie, a French company founded in 2011 by Thibault Lamarque, rents microfiltered water fountains—with water bottled on-site in reusable glass bottles—to businesses, hotels, and restaurants.
- Castalie 7,000 water fountains in 2025, and its water is consumed by 15 million people each month, according to figures cited in the article.
- The Castalie system Castalie 0.5-micron microfiltration with an activated carbon filter, removing chlorine, heavy metals, pesticides, and PFAS without removing minerals.
- Castalie its first two restaurant clients in Paris in September 2011, and then expanded from 125 water fountains in 2013 to 1,500 in 2018.
- Castalie doubled its revenue in three years, from 8 M€ in 2021 to 16 M€ in 2024, and is aiming for 100 M€ within five years.
- Castalie €100,000 in a Life Cycle Assessment conducted in collaboration with the consulting firm Quantis, and became a Socially Responsible Enterprise (ESUS) in 2019.
- 1 liter of Castalie water Castalie 88% fewer GHG emissions per liter (carbon scope, Quantis LCA certified to ISO 14040/14044).
- Castalie its product line for home use with a residential reverse osmosis system that removes chlorine, nitrates, sulfates, PFAS, and pesticides.
Source: Le Plongeoir, newsletter #88 “Plongeon Portrait” (sponsored content), June 20, 2025 — article by Guillaume Fourdinier. Read the original article
