Their concerns seemed to be 1) dogs drinking from the fountains, and 2) use by people for whom hygiene is problematic (quite a few homeless people live in the parks). Presumably they are worried that a previous user could have left pathogen-laden saliva on the fountain. I pointed out that few diseases are transmitted from dogs to humans, and that I have a robust immune system.

Outdoor urban water fountains are used by birds a lot -- which is what made me wonder about them in the first place. Pigeons in particular seem to just sit there hoping water will appear. I don't have much knowledge of zoonotic diseases in birds but I know there are some.

Are Americans uniquely germ-phobic? I've heard there is considerable emphasis on cleanliness in Japan, but don't have personal knowledge of the phenomenon in that (or any other) culture other than my own.

I am inclined to think if disease transmission via water fountain were a problem, someone would know about it.