Unable to answer "Doit-on payer pour l’utiliser ?" – Eau potable pour citerne de véhicule de loisirs – https://osm.org/node/11223256621 via StreetComplete_ee 63.1:

It's more like a laundry place...

Attached photo(s):
https://streetcomplete.app/p/342396.jpg
https://streetcomplete.app/p/342397.jpg