May be a simple case of mixed metaphors (or adjectives) but In my experience the use of the word “crystal” as an adjective is normally used to describe the clarity of something, in this case water. The word I would have expected to follow “crystal” would be “clear”, but crystal clear water impies that it is clean also.
And one would expect POTUS to boast of “clean” air as an accomplishment.
But we are to watch the water.
Clean vs clear. One ends with N, one ends with R. N R?