Disgusting, but yeah, I guess that's why purification is so important. And I used to love those fountains when I was a kid. I guess the sprinkler on the lawn was a bit safer, even if wasting water. Of course, if you had dogs doing their business on the yard, there's probably some risk of parasites. :/
https://en.m.wikipedia.org/wiki/Water_purification#Ozone_dis...
https://en.m.wikipedia.org/wiki/Water_chlorination