The provisions of NRS 445A.025 to 445A.050, inclusive, do not apply to:
1. A public water system that serves a population of 100,000 or more in a county whose population is 700,000 or more.
2. A water authority, as defined pursuant to NRS 377B.040, and any political subdivision that receives all or a part of its water supply from such a water authority in a county whose population is 700,000 or more.
3. Purveyors of bottled water who label their containers to inform the purchaser that the naturally occurring fluoride concentration of the water has been adjusted to recommended levels.
4. A supplier of water who supplies water to less than 500 users.