Inorganic chemicals
Fluoride in U.S. tap water
1,249 public water systems across 44 U.S. states report Fluoride in their annual Consumer Confidence Report. 7 sit at or above the federal limit.
What it is
A mineral often added to drinking water to help prevent tooth decay.
Why it's regulated
Beneficial at low levels, but long-term exposure above the federal limit can cause bone disease and tooth mottling.
At or above the federal limit (7)
| Water system | Measured | vs. limit |
|---|---|---|
| Pittsburgh, PA 2024 annual report | 101 mg/L | 25.3× the limit |
| Pixley Public Util Dist — Pixley, Ca, CA 2023 annual report | 0.11–16 mg/L | 4.0× the limit |
| Mcfarland, City of — Mcfarland, Ca, CA 2023 annual report | 0.2–10 mg/L | 2.5× the limit |
| Yonkers, NY 2024 annual report | 5 mg/L | 1.3× the limit |
| Frisco, TX 2024 annual report | 4 mg/L | 1.0× the limit |
| San Bernardino Valley Wd — San Bernardino, Ca, CA 2023 annual report | 4 mg/L | 1.0× the limit |
| St Petersburg, FL 2024 annual report | 4 mg/L | 1.0× the limit |
Approaching the limit (5)
| Water system | Measured | vs. limit |
|---|---|---|
| Goodyear, AZ 2024 annual report | 3.46 mg/L | 0.9× the limit |
| Kinneloa Irrigation Dist. — Pasadena, Ca, CA 2021 annual report | 0.86–3.4 mg/L | 0.8× the limit |
| San Antonio, TX 2023 annual report | 0.15–3.31 mg/L | 0.8× the limit |
| North Trails Mutual Water Company — Agua Dulce, Ca, CA 2023 annual report | 3.3 mg/L | 0.8× the limit |
| North Trails Mutual Water Company — Agua Dulce, Ca, CA 2022 annual report | 3.2 mg/L | 0.8× the limit |
Within the federal limit (1236)
Showing 50 of 1236. The full list is in the JSON API.
Fluoride by state
Every state where a public water system reports Fluoride in its annual report, ranked by systems at or above the federal limit.
Frequently asked
+What is Fluoride?
A mineral often added to drinking water to help prevent tooth decay. Beneficial at low levels, but long-term exposure above the federal limit can cause bone disease and tooth mottling.
+What is the federal limit for Fluoride in drinking water?
The federal MCL for Fluoride is 4 mg/L. The EPA enforces this against the regulated reporting statistic (typically a running annual average or 90th percentile), not a single-sample spike.
+How many U.S. water systems have Fluoride over the federal limit?
7 of the 1249 public water systems on The Water Map report Fluoride at or above its federal limit, spanning 44 U.S. states. The full list is on this page.
+Which states report the most Fluoride in their drinking water?
Of the systems on The Water Map, California (3 systems at or above the limit), Texas (1 system at or above the limit), Florida (1 system at or above the limit) report the most Fluoride exceedances. The state-by-state table on this page lists every state.
+How can I check if Fluoride is in my city's tap water?
Search your city on The Water Map (https://www.thewatermap.com/) or browse the list on this page. Every U.S. public water utility is required to publish an annual Consumer Confidence Report that lists every contaminant it measured, including Fluoride.