The question to me is - do we even have to fluoridate water and is this really the best approach?
For example, most European countries do not commonly use fluoride in their water supply, and everyone's just fine! No extra cavities, no special health risks. People commonly drink tap water and do not care about potential for any adverse effects, because it's just that - clean water. And for any teeth-related issues, you already have your toothpaste providing more than enough fluorine.