Spatial distribution of potable water chemistry and aggressiveness indices in France using a novel visualisation tool of the SISE-Eaux database

The graphical abstract shows the workflow detailed in the article. The data from the SISE-Eaux database are first retrieved as two separate files: a PLV file containing location, date and identification, and a RESULT file containing the analysed data. These files then undergo a preprocessing step consisting of reformatting, annual aggregation and data harmonisation. This unified database is then used to find correlations between analysed parameters, plot geochemical maps and perform non-parametric tests across a large number of parameters. Ensuring drinking-water quality is essential both for safe human consumption and for preserving water supply infrastructures. In France, distributed waters interact with a diverse materials, including metallic pipes, cement-based linings, asbestos-cement pipes, and polymeric networks, making the assessment of water aggressiveness particularly important. This study proposes a dedicated workflow for exploiting the nationwide SISE-Eaux regulatory database to analyse and visualise spatial patterns of drinking-water chemistry and aggressiveness across France. The approach combines data preprocessing, harmonisation of analytical fields, calculation of aggressiveness indices, annual aggregation at the municipality scale, and municipality-level spatial attribution. Using data from 2020 to 2022, the study examines the geographical distribution of major chemical parameters and four complementary aggressiveness indices: the Langelier Index, Ryznar Stability Index, Larson–Skold Index, and Basson Index. The results highlight regional contrasts in water chemistry, especially for calcium, hydrogenocarbonates, sulphates, chlorides, and pH, in relation to geological context. They also show that the different indices do not provide identical classifications, confirming the value of a multi-indicator approach when interpreting water aggressiveness at the national scale. The proposed workflow should therefore be understood as a reproducible exploratory framework for supporting the large-scale interpretation of drinking-water chemistry and potential water–infrastructure interactions.