Fluoride
Plover Waterworks
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 |
|---|---|---|---|---|
| 2014 | 0.671 ppm | 27 | 27 | 0.110 ppm - 0.940 ppm |
| 2015 | 0.773 ppm | 24 | 24 | 0.581 ppm - 0.900 ppm |
| 2016 | 0.690 ppm | 24 | 24 | 0.575 ppm - 0.810 ppm |
| 2017 | 0.693 ppm | 27 | 27 | 0.130 ppm - 0.880 ppm |
| 2018 | 0.766 ppm | 24 | 24 | 0.414 ppm - 0.990 ppm |
| 2019 | 0.724 ppm | 22 | 22 | 0.516 ppm - 0.949 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 |
|---|---|---|
| 2014-01-07 | 115158001 | 0.682 ppm |
| 2014-01-07 | 115158001 | 0.690 ppm |
| 2014-02-10 | 118929001 | 0.698 ppm |
| 2014-02-10 | 118929001 | 0.860 ppm |
| 2014-03-10 | 122461001 | 0.679 ppm |
| 2014-03-10 | 122461001 | 0.940 ppm |
| 2014-03-17 | 774962 | 0.110 ppm |
| 2014-03-17 | 774961 | 0.560 ppm |
| 2014-03-17 | 774960 | 0.610 ppm |
| 2014-04-07 | 126333001 | 0.643 ppm |
| 2014-04-07 | 126333001 | 0.710 ppm |
| 2014-05-28 | 135374001 | 0.559 ppm |
| 2014-05-28 | 135374001 | 0.660 ppm |
| 2014-06-03 | 136585001 | 0.646 ppm |
| 2014-06-03 | 136585001 | 0.830 ppm |
| 2014-07-28 | 147957001 | 0.680 ppm |
| 2014-07-28 | 147957001 | 0.710 ppm |
| 2014-08-04 | 148927001 | 0.690 ppm |
| 2014-08-04 | 148927001 | 0.722 ppm |
| 2014-09-09 | 156218001 | 0.600 ppm |
| 2014-09-09 | 156218001 | 0.624 ppm |
| 2014-10-14 | 163737001 | 0.760 ppm |
| 2014-10-14 | 163737001 | 0.809 ppm |
| 2014-11-03 | 166504001 | 0.602 ppm |
| 2014-11-03 | 166504001 | 0.670 ppm |
| 2014-12-02 | 170671001 | 0.670 ppm |
| 2014-12-02 | 170671001 | 0.696 ppm |
| 2015-01-26 | 177078001 | 0.883 ppm |
| 2015-01-26 | 177078001 | 0.900 ppm |
| 2015-02-09 | 178974001 | 0.667 ppm |
| 2015-02-09 | 178974001 | 0.680 ppm |
| 2015-03-09 | 182668001 | 0.900 ppm |
| 2015-03-09 | 182668001 | 0.900 ppm |
| 2015-04-13 | 187620001 | 0.690 ppm |
| 2015-04-13 | 187620001 | 0.730 ppm |
| 2015-05-04 | 191014001 | 0.630 ppm |
| 2015-05-04 | 191014001 | 0.637 ppm |
| 2015-06-01 | 197009001 | 0.707 ppm |
| 2015-06-01 | 197009001 | 0.750 ppm |
| 2015-07-13 | 205273001 | 0.780 ppm |
| 2015-07-13 | 205273001 | 0.816 ppm |
| 2015-08-10 | 210662001 | 0.765 ppm |
| 2015-08-10 | 210662001 | 0.790 ppm |
| 2015-09-01 | 214947001 | 0.890 ppm |
| 2015-09-01 | 214947001 | 0.892 ppm |
| 2015-10-05 | 221893001 | 0.841 ppm |
| 2015-10-05 | 221893001 | 0.890 ppm |
| 2015-11-03 | 226981001 | 0.581 ppm |
| 2015-11-03 | 226981001 | 0.650 ppm |
| 2015-12-01 | 230808001 | 0.785 ppm |
| 2015-12-01 | 230808001 | 0.790 ppm |
| 2016-01-19 | 236320001 | 0.575 ppm |
| 2016-01-19 | 236320001 | 0.800 ppm |
| 2016-02-22 | 241054001 | 0.698 ppm |
| 2016-02-22 | 241054001 | 0.730 ppm |
| 2016-03-21 | 245401001 | 0.660 ppm |
| 2016-03-21 | 245401001 | 0.689 ppm |
| 2016-04-19 | 250043001 | 0.610 ppm |
| 2016-04-19 | 250043001 | 0.715 ppm |
| 2016-05-17 | 255358001 | 0.674 ppm |
| 2016-05-17 | 255358001 | 0.750 ppm |
| 2016-06-21 | 262305001 | 0.638 ppm |
| 2016-06-21 | 262305001 | 0.710 ppm |
| 2016-07-20 | 267565001 | 0.641 ppm |
| 2016-07-20 | 267565001 | 0.660 ppm |
| 2016-08-23 | 273758001 | 0.590 ppm |
| 2016-08-23 | 273758001 | 0.629 ppm |
| 2016-09-28 | 281073001 | 0.675 ppm |
| 2016-09-28 | 281073001 | 0.710 ppm |
| 2016-10-17 | 284493001 | 0.743 ppm |
| 2016-10-17 | 284493001 | 0.810 ppm |
| 2016-11-07 | 287621001 | 0.745 ppm |
| 2016-11-07 | 287621001 | 0.770 ppm |
| 2016-12-08 | 292195001 | 0.637 ppm |
| 2016-12-08 | 292195001 | 0.690 ppm |
| 2017-01-25 | 297833001 | 0.657 ppm |
| 2017-01-25 | 297833001 | 0.860 ppm |
| 2017-02-27 | 301652001 | 0.652 ppm |
| 2017-02-27 | 301652001 | 0.820 ppm |
| 2017-03-13 | 303840001 | 0.710 ppm |
| 2017-03-13 | 303840001 | 0.712 ppm |
| 2017-04-19 | 311040001 | 0.710 ppm |
| 2017-04-19 | 311040001 | 0.797 ppm |
| 2017-05-16 | 316414001 | 0.680 ppm |
| 2017-05-16 | 316414001 | 0.689 ppm |
| 2017-06-27 | 324919001 | 0.534 ppm |
| 2017-06-27 | 324919001 | 0.590 ppm |
| 2017-07-25 | 331326001 | 0.735 ppm |
| 2017-07-25 | 331326001 | 0.810 ppm |
| 2017-08-15 | 1011284 | 0.130 ppm |
| 2017-08-15 | 1011308 | 0.710 ppm |
| 2017-08-15 | 1011311 | 0.770 ppm |
| 2017-08-21 | 337132001 | 0.784 ppm |
| 2017-08-21 | 337132001 | 0.880 ppm |
| 2017-09-26 | 345255001 | 0.589 ppm |
| 2017-09-26 | 345255001 | 0.640 ppm |
| 2017-10-23 | 350605001 | 0.701 ppm |
| 2017-10-23 | 350605001 | 0.730 ppm |
| 2017-11-08 | 353514001 | 0.673 ppm |
| 2017-11-08 | 353514001 | 0.690 ppm |
| 2017-12-07 | 359226001 | 0.713 ppm |
| 2017-12-07 | 359226001 | 0.750 ppm |
| 2018-01-29 | 364668001 | 0.699 ppm |
| 2018-01-29 | 364668001 | 0.910 ppm |
| 2018-02-21 | 368224001 | 0.670 ppm |
| 2018-02-21 | 368224001 | 0.770 ppm |
| 2018-03-19 | 371951001 | 0.668 ppm |
| 2018-03-19 | 371951001 | 0.840 ppm |
| 2018-04-25 | 378487001 | 0.623 ppm |
| 2018-04-25 | 378487001 | 0.830 ppm |
| 2018-05-15 | 382732001 | 0.698 ppm |
| 2018-05-15 | 382732001 | 0.760 ppm |
| 2018-06-26 | 391200001 | 0.783 ppm |
| 2018-06-26 | 391200001 | 0.800 ppm |
| 2018-07-30 | 397816001 | 0.668 ppm |
| 2018-07-30 | 397816001 | 0.720 ppm |
| 2018-08-28 | 404315001 | 0.414 ppm |
| 2018-08-28 | 404315001 | 0.650 ppm |
| 2018-09-24 | 410111001 | 0.983 ppm |
| 2018-09-24 | 410111001 | 0.990 ppm |
| 2018-10-23 | 416242001 | 0.790 ppm |
| 2018-10-23 | 416242001 | 0.814 ppm |
| 2018-11-27 | 421531001 | 0.772 ppm |
| 2018-11-27 | 421531001 | 0.900 ppm |
| 2018-12-11 | 424023001 | 0.800 ppm |
| 2018-12-11 | 424023001 | 0.821 ppm |
| 2019-01-29 | 429286001 | 0.700 ppm |
| 2019-01-29 | 429286001 | 0.753 ppm |
| 2019-02-19 | 432392001 | 0.640 ppm |
| 2019-02-19 | 432392001 | 0.755 ppm |
| 2019-03-19 | 436347001 | 0.698 ppm |
| 2019-03-19 | 436347001 | 0.720 ppm |
| 2019-04-22 | 441828001 | 0.708 ppm |
| 2019-04-22 | 441828001 | 0.800 ppm |
| 2019-05-21 | 447567001 | 0.840 ppm |
| 2019-05-21 | 447567001 | 0.931 ppm |
| 2019-06-24 | 453836001 | 0.900 ppm |
| 2019-06-24 | 453836001 | 0.949 ppm |
| 2019-08-20 | 465169001 | 0.516 ppm |
| 2019-08-20 | 465169001 | 0.630 ppm |
| 2019-09-09 | 468850001 | 0.542 ppm |
| 2019-09-09 | 468850001 | 0.640 ppm |
| 2019-10-15 | 476695001 | 0.778 ppm |
| 2019-10-15 | 476695001 | 0.800 ppm |
| 2019-11-18 | 482228001 | 0.686 ppm |
| 2019-11-18 | 482228001 | 0.700 ppm |
| 2019-12-16 | 486839001 | 0.601 ppm |
| 2019-12-16 | 486839001 | 0.650 ppm |