RE #6: Hmmmm.... a number of NESs have already weighed in here and in the discussion linked in #3 to indicate that the term is not an appropriate translation of "Quellwasser."
Also, the search that I linked to in #2 clearly indicates that it is a term that is almost exclusively used by Bach &Co. for their products. [I know folks don't always like to follow links. Just use your favorite search engine to search for "rock water" (with that punctuation) to see the results that come up for that term.] When the term is used to refer to something else, it is typically a geographical feature somewhere (not a type of water) or in a name (such as of a resort).
That said, it appears that the offending translation has already been removed (Thank you, Leo team!)
OT: BTW -- "LEO is not limited to words from scientific contexts and a marketing context is as valid a "general context" as any other." is a run-on sentence and needs a comma before "and." (Sorry, that's one of my pet peeves -- and I'm amazed how many NESs who otherwise write decently make the same mistake.)