Fluoride
Stillwater Water Plant
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems. Read More.
Fluoride has been promoted as a chemical that reduces dental cavities. Yet it is now well-established that fluoride primarily exerts its protective effects through topical mechanisms, such as sodium fluoride in toothpaste and mouthwash. In contrast, long-term ingestion of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth. EPA's maximum legal limit is set at 4 parts per million (ppm) to prevent skeletal fluorosis, a condition where bones become brittle and more susceptible to fractures, although these effects may occur at lower doses.
Even fluoride levels of 0.7 ppm, the amount of fluoride in drinking water recommended by the U.S. Public Health Service, can result in too much fluoride for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water. The National Toxicology Program is investigating the potential for low doses of fluoride to alter thyroid function and childhood brain development.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 0.723 ppm | 12 | 12 | 0.580 ppm - 0.830 ppm |
| 2015 | 0.698 ppm | 13 | 13 | 0.440 ppm - 0.920 ppm |
| 2016 | 0.537 ppm | 12 | 12 | 0.260 ppm - 0.868 ppm |
| 2017 | 0.448 ppm | 13 | 13 | 0.204 ppm - 0.660 ppm |
| 2018 | 0.463 ppm | 13 | 13 | 0.370 ppm - 0.550 ppm |
| 2019 | 0.497 ppm | 12 | 12 | 0.400 ppm - 0.630 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EPA Maximum Contaminant
Level (MCL) 4 ppm
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-01-08 | 4A08041-03 | 0.730 ppm |
| 2014-02-17 | 4B17017-03 | 0.580 ppm |
| 2014-03-24 | 4C24007-03 | 0.610 ppm |
| 2014-04-21 | 4D21003-03 | 0.730 ppm |
| 2014-05-15 | 4E15063-03 | 0.750 ppm |
| 2014-06-12 | 4F12016-03 | 0.750 ppm |
| 2014-07-21 | 4G21010-03 | 0.640 ppm |
| 2014-08-19 | 4H19011-03 | 0.810 ppm |
| 2014-09-15 | 4I15024-03 | 0.830 ppm |
| 2014-10-21 | 4J21037-03 | 0.770 ppm |
| 2014-11-19 | 4K19015-03 | 0.830 ppm |
| 2014-12-12 | 4L12007-03 | 0.650 ppm |
| 2015-01-16 | 5A16018-03 | 0.840 ppm |
| 2015-02-18 | 5B18065-03 | 0.920 ppm |
| 2015-03-18 | 5C18002-03 | 0.700 ppm |
| 2015-04-24 | 5D24004-03 | 0.610 ppm |
| 2015-05-20 | 5E20044-03 | 0.740 ppm |
| 2015-06-19 | 5F19004-03 | 0.700 ppm |
| 2015-07-14 | 5G14051-03 | 0.880 ppm |
| 2015-08-20 | 5H20042-03 | 0.900 ppm |
| 2015-09-22 | 5I22026-03 | 0.630 ppm |
| 2015-10-20 | 5J20028-03 | 0.640 ppm |
| 2015-10-22 | 5J22074-01 | 0.550 ppm |
| 2015-11-19 | 5K19010-03 | 0.520 ppm |
| 2015-12-17 | 5L17052-03 | 0.440 ppm |
| 2016-01-14 | 6A14008-03 | 0.540 ppm |
| 2016-02-16 | 6B16014-03 | 0.460 ppm |
| 2016-03-15 | 6C15050-03 | 0.260 ppm |
| 2016-04-18 | 6D18007-03 | 0.340 ppm |
| 2016-05-11 | 1490657 | 0.416 ppm |
| 2016-06-13 | 1499036 | 0.261 ppm |
| 2016-07-12 | 1506647 | 0.675 ppm |
| 2016-08-09 | 1515033 | 0.868 ppm |
| 2016-09-06 | 1522236 | 0.762 ppm |
| 2016-10-13 | 1533358 | 0.836 ppm |
| 2016-11-15 | 1549512 | 0.268 ppm |
| 2016-12-12 | 1547595 | 0.754 ppm |
| 2017-01-19 | 1557149 | 0.294 ppm |
| 2017-02-14 | 1563950 | 0.407 ppm |
| 2017-03-09 | 1570536 | 0.204 ppm |
| 2017-04-13 | 1579824 | 0.435 ppm |
| 2017-05-08 | 1586454 | 0.530 ppm |
| 2017-06-13 | 1596077 | 0.560 ppm |
| 2017-07-11 | 1603341 | 0.660 ppm |
| 2017-08-07 | 7H07002-04 | 0.320 ppm |
| 2017-08-29 | 7H29039-01 | 0.460 ppm |
| 2017-09-21 | 7I21044-04 | 0.480 ppm |
| 2017-10-11 | 7J11050-04 | 0.460 ppm |
| 2017-11-15 | 7K15023-04 | 0.500 ppm |
| 2017-12-08 | 7L08007-03 | 0.520 ppm |
| 2018-01-03 | 8A03032-04 | 0.510 ppm |
| 2018-02-02 | AB02005-04 | 0.410 ppm |
| 2018-03-02 | AC02002-04 | 0.500 ppm |
| 2018-04-02 | AD02022-04 | 0.370 ppm |
| 2018-04-18 | AD18118-04 | 0.370 ppm |
| 2018-05-01 | AE01003-04 | 0.470 ppm |
| 2018-06-04 | AF04006-04 | 0.450 ppm |
| 2018-07-02 | AG02004-04 | 0.440 ppm |
| 2018-08-03 | AH03007-04 | 0.480 ppm |
| 2018-09-07 | AI07002-03 | 0.470 ppm |
| 2018-10-08 | AJ08001-03 | 0.550 ppm |
| 2018-11-06 | AK06001-03 | 0.520 ppm |
| 2018-12-03 | AL03002-04 | 0.480 ppm |
| 2019-01-02 | BA02017-04 | 0.500 ppm |
| 2019-02-01 | BB01001-04 | 0.420 ppm |
| 2019-03-04 | BC04002-04 | 0.420 ppm |
| 2019-04-04 | BD04011-04 | 0.510 ppm |
| 2019-05-06 | BE06002-04 | 0.470 ppm |
| 2019-06-10 | BF10002-04 | 0.470 ppm |
| 2019-07-01 | BG01004-04 | 0.440 ppm |
| 2019-08-05 | BH05003-04 | 0.400 ppm |
| 2019-09-04 | BI04019-04 | 0.630 ppm |
| 2019-10-03 | BJ03005-04 | 0.550 ppm |
| 2019-11-04 | BK04002-04 | 0.610 ppm |
| 2019-12-09 | BL09003-04 | 0.540 ppm |