In the United States, who has the authority to DECIDE whether a community's water supply is fluoridated?

Correct answer: B. State and local governments

• A. The federal government does NOT mandate fluoridation. The US Public Health Service recommendation of 0.7 mg/L is guidance and is explicitly NOT an enforceable standard, and the CDC does not issue mandates.
• B. CORRECT. STATE AND LOCAL GOVERNMENTS decide whether to implement community water fluoridation. Some states mandate it for water systems above a certain population; most leave the decision to counties, cities or local referendums. The federal government has no legal authority to require a community to fluoridate, nor to require one to stop.
• C. The ADA is a professional association. It strongly ADVOCATES for community water fluoridation and provides scientific support, but it holds no regulatory or legislative power.
• D. The EPA's federal authority is real but limited to a different question: under the Safe Drinking Water Act it sets the MAXIMUM allowable fluoride concentration for safety. It regulates the ceiling; it does not order communities to fluoridate.

Note: Hold the two roles apart — FEDERAL (EPA) sets the enforceable maximum concentration and the PHS recommends the optimal level of 0.7 mg/L; STATE and LOCAL governments decide whether to fluoridate at all. If a question asks who REGULATES the maximum safe level, the federal answer is right; if it asks who DECIDES to fluoridate, it is state and local.