Fluoride
Fort Atkinson 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 | 0.608 ppm | 29 | 29 | 0.0850 ppm - 0.920 ppm |
| 2015 | 0.718 ppm | 24 | 24 | 0.557 ppm - 0.870 ppm |
| 2016 | 0.775 ppm | 24 | 24 | 0.640 ppm - 0.910 ppm |
| 2017 | 0.703 ppm | 29 | 29 | 0.110 ppm - 1.02 ppm |
| 2018 | 0.806 ppm | 24 | 24 | 0.640 ppm - 0.940 ppm |
| 2019 | 0.749 ppm | 24 | 24 | 0.326 ppm - 0.907 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 | 115261001 | 0.685 ppm |
| 2014-01-08 | 115261001 | 0.890 ppm |
| 2014-02-12 | 119422001 | 0.523 ppm |
| 2014-02-12 | 119422001 | 0.790 ppm |
| 2014-03-04 | 121693001 | 0.614 ppm |
| 2014-03-04 | 121693001 | 0.830 ppm |
| 2014-04-09 | 127050001 | 0.615 ppm |
| 2014-04-09 | 127050001 | 0.750 ppm |
| 2014-05-06 | 131129001 | 0.648 ppm |
| 2014-05-06 | 131129001 | 0.790 ppm |
| 2014-06-11 | 138477001 | 0.658 ppm |
| 2014-06-11 | 138477001 | 0.780 ppm |
| 2014-07-02 | 142729001 | 0.631 ppm |
| 2014-07-02 | 142729001 | 0.700 ppm |
| 2014-07-30 | 807121 | 0.0850 ppm |
| 2014-07-30 | 807118 | 0.120 ppm |
| 2014-07-30 | 807124 | 0.120 ppm |
| 2014-07-30 | 807112 | 0.140 ppm |
| 2014-07-30 | 807115 | 0.140 ppm |
| 2014-08-12 | 150657001 | 0.720 ppm |
| 2014-08-12 | 150657001 | 0.920 ppm |
| 2014-09-03 | 154747001 | 0.644 ppm |
| 2014-09-03 | 154747001 | 0.680 ppm |
| 2014-10-08 | 162484001 | 0.650 ppm |
| 2014-10-08 | 162484001 | 0.685 ppm |
| 2014-11-06 | 167455001 | 0.619 ppm |
| 2014-11-06 | 167455001 | 0.670 ppm |
| 2014-12-10 | 172056001 | 0.720 ppm |
| 2014-12-10 | 172056001 | 0.810 ppm |
| 2015-01-15 | 175914001 | 0.557 ppm |
| 2015-01-15 | 175914001 | 0.780 ppm |
| 2015-02-10 | 178946001 | 0.681 ppm |
| 2015-02-10 | 178946001 | 0.870 ppm |
| 2015-03-05 | 182189001 | 0.690 ppm |
| 2015-03-05 | 182189001 | 0.745 ppm |
| 2015-04-23 | 189633001 | 0.760 ppm |
| 2015-04-23 | 189633001 | 0.795 ppm |
| 2015-05-06 | 191819001 | 0.710 ppm |
| 2015-05-06 | 191819001 | 0.773 ppm |
| 2015-06-10 | 198845001 | 0.680 ppm |
| 2015-06-10 | 198845001 | 0.753 ppm |
| 2015-07-07 | 203823001 | 0.600 ppm |
| 2015-07-07 | 203823001 | 0.716 ppm |
| 2015-08-11 | 210933001 | 0.640 ppm |
| 2015-08-11 | 210933001 | 0.734 ppm |
| 2015-09-03 | 215517001 | 0.690 ppm |
| 2015-09-03 | 215517001 | 0.722 ppm |
| 2015-10-06 | 222043001 | 0.670 ppm |
| 2015-10-06 | 222043001 | 0.794 ppm |
| 2015-11-03 | 226728001 | 0.740 ppm |
| 2015-11-03 | 226728001 | 0.779 ppm |
| 2015-12-10 | 232264001 | 0.630 ppm |
| 2015-12-10 | 232264001 | 0.730 ppm |
| 2016-01-05 | 234329001 | 0.742 ppm |
| 2016-01-05 | 234329001 | 0.780 ppm |
| 2016-02-22 | 240532001 | 0.690 ppm |
| 2016-02-22 | 240532001 | 0.765 ppm |
| 2016-03-01 | 241576001 | 0.660 ppm |
| 2016-03-01 | 241576001 | 0.740 ppm |
| 2016-04-13 | 248673001 | 0.758 ppm |
| 2016-04-13 | 248673001 | 0.770 ppm |
| 2016-05-03 | 252418001 | 0.785 ppm |
| 2016-05-03 | 252418001 | 0.790 ppm |
| 2016-06-07 | 258596001 | 0.690 ppm |
| 2016-06-07 | 258596001 | 0.910 ppm |
| 2016-07-07 | 264653001 | 0.750 ppm |
| 2016-07-07 | 264653001 | 0.786 ppm |
| 2016-08-10 | 271398001 | 0.773 ppm |
| 2016-08-10 | 271398001 | 0.890 ppm |
| 2016-09-01 | 275225001 | 0.640 ppm |
| 2016-09-01 | 275225001 | 0.812 ppm |
| 2016-10-11 | 283033001 | 0.880 ppm |
| 2016-10-11 | 283033001 | 0.902 ppm |
| 2016-11-02 | 287038001 | 0.710 ppm |
| 2016-11-02 | 287038001 | 0.792 ppm |
| 2016-12-06 | 291486001 | 0.790 ppm |
| 2016-12-06 | 291486001 | 0.793 ppm |
| 2017-01-03 | 294543001 | 0.700 ppm |
| 2017-01-03 | 294543001 | 0.785 ppm |
| 2017-02-15 | 300261001 | 0.720 ppm |
| 2017-02-15 | 300261001 | 0.763 ppm |
| 2017-03-08 | 303181001 | 0.870 ppm |
| 2017-03-08 | 303181001 | 0.914 ppm |
| 2017-04-12 | 309466001 | 0.770 ppm |
| 2017-04-12 | 309466001 | 0.776 ppm |
| 2017-05-10 | 315053001 | 0.870 ppm |
| 2017-05-10 | 315053001 | 1.02 ppm |
| 2017-06-13 | 321327001 | 0.780 ppm |
| 2017-06-13 | 321327001 | 0.789 ppm |
| 2017-07-05 | 325841001 | 0.630 ppm |
| 2017-07-05 | 325841001 | 0.794 ppm |
| 2017-07-19 | 1005218 | 0.110 ppm |
| 2017-07-19 | 1005230 | 0.120 ppm |
| 2017-07-19 | 1005222 | 0.130 ppm |
| 2017-07-19 | 1005214 | 0.130 ppm |
| 2017-07-19 | 1005226 | 0.160 ppm |
| 2017-08-09 | 334541001 | 0.890 ppm |
| 2017-08-09 | 334541001 | 0.901 ppm |
| 2017-09-06 | 340078001 | 0.750 ppm |
| 2017-09-06 | 340078001 | 0.851 ppm |
| 2017-10-10 | 347728001 | 0.798 ppm |
| 2017-10-10 | 347728001 | 0.890 ppm |
| 2017-11-01 | 351872001 | 0.790 ppm |
| 2017-11-01 | 351872001 | 0.832 ppm |
| 2017-12-05 | 357503001 | 0.890 ppm |
| 2017-12-05 | 357503001 | 0.952 ppm |
| 2018-01-09 | 361976001 | 0.860 ppm |
| 2018-01-09 | 361976001 | 0.907 ppm |
| 2018-02-08 | 366080001 | 0.872 ppm |
| 2018-02-08 | 366080001 | 0.940 ppm |
| 2018-03-01 | 368945001 | 0.830 ppm |
| 2018-03-01 | 368945001 | 0.886 ppm |
| 2018-04-13 | 376293001 | 0.700 ppm |
| 2018-04-13 | 376293001 | 0.843 ppm |
| 2018-05-03 | 379768001 | 0.700 ppm |
| 2018-05-03 | 379768001 | 0.840 ppm |
| 2018-06-05 | 386159001 | 0.780 ppm |
| 2018-06-05 | 386159001 | 0.845 ppm |
| 2018-07-03 | 392172001 | 0.770 ppm |
| 2018-07-03 | 392172001 | 0.876 ppm |
| 2018-08-14 | 400772001 | 0.640 ppm |
| 2018-08-14 | 400772001 | 0.810 ppm |
| 2018-09-05 | 405109001 | 0.670 ppm |
| 2018-09-05 | 405109001 | 0.799 ppm |
| 2018-10-09 | 413070001 | 0.814 ppm |
| 2018-10-09 | 413070001 | 0.820 ppm |
| 2018-11-06 | 418121001 | 0.680 ppm |
| 2018-11-06 | 418121001 | 0.710 ppm |
| 2018-12-12 | 424255001 | 0.868 ppm |
| 2018-12-12 | 424255001 | 0.890 ppm |
| 2019-01-02 | 425830001 | 0.750 ppm |
| 2019-01-02 | 425830001 | 0.781 ppm |
| 2019-02-18 | 431668001 | 0.787 ppm |
| 2019-02-18 | 431668001 | 0.850 ppm |
| 2019-03-05 | 433723001 | 0.870 ppm |
| 2019-03-05 | 433723001 | 0.904 ppm |
| 2019-04-09 | 439432001 | 0.756 ppm |
| 2019-04-09 | 439432001 | 0.760 ppm |
| 2019-05-08 | 444781001 | 0.610 ppm |
| 2019-05-08 | 444781001 | 0.750 ppm |
| 2019-06-11 | 451001001 | 0.720 ppm |
| 2019-06-11 | 451001001 | 0.833 ppm |
| 2019-07-02 | 455193001 | 0.720 ppm |
| 2019-07-02 | 455193001 | 0.846 ppm |
| 2019-08-13 | 463159001 | 0.650 ppm |
| 2019-08-13 | 463159001 | 0.742 ppm |
| 2019-09-04 | 467547001 | 0.890 ppm |
| 2019-09-04 | 467547001 | 0.907 ppm |
| 2019-10-10 | 475735001 | 0.810 ppm |
| 2019-10-10 | 475735001 | 0.891 ppm |
| 2019-11-06 | 480015001 | 0.700 ppm |
| 2019-11-06 | 480015001 | 0.761 ppm |
| 2019-12-10 | 485213001 | 0.326 ppm |
| 2019-12-10 | 485213001 | 0.350 ppm |