From acidic water in volcanic areas to high copper levels in French cities, a massive citizen study into the quality of France's water revealed some surprising things, write researchers Nicolas Dietrich, Johanne Teychené and Nathalie Clergerie. In 2023, thousands of citizens took part in a research project aimed at mapping water quality across France. AdvertisementThis gesture, both simple and fun, actually hides valuable measurements: pH (or acidity), nitrate concentrations from fertilisers, chlorine levels, as well as heavy metals such as copper or lead. Some wells break all iron records, with concentrations reaching up to 25 mg/L, or 500 times the drinking water limit. In cities, it picks up chlorine, copper, and household waste.

Source: The Local January 06, 2026 13:38 UTC