Localization of “High-Risk to Perchlorate Contamination” groundwater resources into mainland France
Résumé
This study follows the recent findings of perchlorate ions in several French aquifers, and particularly in the South-West and in the North of France. The concentration measured in groundwater can exceed the 4 and 15 µg/L values defined by the WHO (World Health Organization) as toxicity thresholds for infants (and pregnant women) and adults, respectively. Nevertheless, the ecotoxicological effects of this oxyanion on the environment remain little known. This study is carried out in the context of horizon-scanning for the future surveillance of emerging compounds in water resources. It aims to highlight, to local stakeholders, areas that can be considered as “risky to perchlorate contamination” under their respective purview.
This study enabled to (i) make the inventory of possible industrial or military sources of emission of perchlorate ions to the aquatic environment, (ii) present their transfer properties towards groundwater on the basis of a bibliographic study, (iii) propose an innovative methodology, mainly based on GIS, for the assessment of groundwater vulnerability to potential contamination by perchlorate ions, (iv) validate, when it is possible, the results of this methodology on the basis of measured concentration of perchlorate ions in groundwater or water supplied, gathered during specific campaigns at different scales (national, regional and local), and (v) edit maps for each French main river basin that highlight areas considered to be at “high-risk”, regarding possible groundwater contamination by perchlorate ions of industrial or military origin.
The methodology developed for this study has been confronted with real in situ analytical results, and has been validated for military and industrial sources of perchlorates. Several “high-risk to perchlorate contamination” areas have been targeted; where such analysis has not been carried out to date, which deserves further study.