i find it hard to believe that all groundwater everywhere in the us is naturally at that rate. the water varies considerably from area to area in regards to everything else so it would seem like some areas would have much less fluoride, others much more. i've gotten my drinking water from a well my entire life so i've never really cared about the whole fluoride debate. my teeth also haven't rotted out of my head like everyone has told me would happen if they stopped fluorodating water
United States