Fluoride
Waunakee 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 | 29 | 29 | 0.0720 ppm - 1.13 ppm |
| 2015 | 0.715 ppm | 24 | 24 | 0.544 ppm - 0.790 ppm |
| 2016 | 0.764 ppm | 24 | 24 | 0.669 ppm - 0.826 ppm |
| 2017 | 0.661 ppm | 29 | 29 | 0.0920 ppm - 0.835 ppm |
| 2018 | 0.786 ppm | 24 | 24 | 0.700 ppm - 0.927 ppm |
| 2019 | 0.760 ppm | 24 | 24 | 0.687 ppm - 0.824 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 |
|---|---|---|
| 2014-01-16 | 116532001 | 0.800 ppm |
| 2014-01-16 | 116532001 | 0.841 ppm |
| 2014-02-10 | 769685 | 0.0720 ppm |
| 2014-02-10 | 769682 | 0.0720 ppm |
| 2014-02-10 | 769679 | 0.0950 ppm |
| 2014-02-10 | 769677 | 0.200 ppm |
| 2014-02-17 | 119976001 | 0.760 ppm |
| 2014-02-17 | 119976001 | 0.806 ppm |
| 2014-03-03 | 121282001 | 0.800 ppm |
| 2014-03-03 | 121282001 | 0.822 ppm |
| 2014-04-02 | 125688001 | 0.797 ppm |
| 2014-04-02 | 125688001 | 0.800 ppm |
| 2014-04-16 | 780795 | 0.0910 ppm |
| 2014-05-06 | 130765001 | 0.710 ppm |
| 2014-05-06 | 130765001 | 0.830 ppm |
| 2014-06-03 | 137495001 | 0.700 ppm |
| 2014-06-03 | 137495001 | 0.785 ppm |
| 2014-07-15 | 145210001 | 0.750 ppm |
| 2014-07-15 | 145210001 | 1.13 ppm |
| 2014-08-18 | 151718001 | 0.749 ppm |
| 2014-08-18 | 151718001 | 0.930 ppm |
| 2014-09-02 | 154300001 | 0.766 ppm |
| 2014-09-02 | 154300001 | 0.770 ppm |
| 2014-10-08 | 162765001 | 0.760 ppm |
| 2014-10-08 | 162765001 | 0.821 ppm |
| 2014-11-05 | 167308001 | 0.610 ppm |
| 2014-11-05 | 167308001 | 0.700 ppm |
| 2014-12-04 | 171254001 | 0.707 ppm |
| 2014-12-04 | 171254001 | 0.790 ppm |
| 2015-01-15 | 175955001 | 0.544 ppm |
| 2015-01-15 | 175955001 | 0.710 ppm |
| 2015-02-09 | 178686001 | 0.599 ppm |
| 2015-02-09 | 178686001 | 0.760 ppm |
| 2015-03-02 | 181248001 | 0.559 ppm |
| 2015-03-02 | 181248001 | 0.790 ppm |
| 2015-04-15 | 188452001 | 0.696 ppm |
| 2015-04-15 | 188452001 | 0.720 ppm |
| 2015-05-06 | 192163001 | 0.720 ppm |
| 2015-05-06 | 192163001 | 0.750 ppm |
| 2015-06-03 | 197704001 | 0.750 ppm |
| 2015-06-03 | 197704001 | 0.767 ppm |
| 2015-07-03 | 203271001 | 0.710 ppm |
| 2015-07-03 | 203271001 | 0.715 ppm |
| 2015-08-11 | 211283001 | 0.619 ppm |
| 2015-08-11 | 211283001 | 0.700 ppm |
| 2015-09-08 | 215767001 | 0.720 ppm |
| 2015-09-08 | 215767001 | 0.770 ppm |
| 2015-10-12 | 223791001 | 0.720 ppm |
| 2015-10-12 | 223791001 | 0.770 ppm |
| 2015-11-05 | 227467001 | 0.729 ppm |
| 2015-11-05 | 227467001 | 0.770 ppm |
| 2015-12-02 | 231023001 | 0.789 ppm |
| 2015-12-02 | 231023001 | 0.790 ppm |
| 2016-01-01 | 234049001 | 0.790 ppm |
| 2016-01-01 | 234049001 | 0.800 ppm |
| 2016-02-14 | 239747001 | 0.770 ppm |
| 2016-02-14 | 239747001 | 0.822 ppm |
| 2016-03-07 | 242866001 | 0.680 ppm |
| 2016-03-07 | 242866001 | 0.720 ppm |
| 2016-04-01 | 246384001 | 0.780 ppm |
| 2016-04-01 | 246384001 | 0.803 ppm |
| 2016-05-04 | 252814001 | 0.780 ppm |
| 2016-05-04 | 252814001 | 0.785 ppm |
| 2016-06-05 | 257916001 | 0.769 ppm |
| 2016-06-05 | 257916001 | 0.800 ppm |
| 2016-07-13 | 266324001 | 0.721 ppm |
| 2016-07-13 | 266324001 | 0.760 ppm |
| 2016-08-01 | 270369001 | 0.691 ppm |
| 2016-08-01 | 270369001 | 0.800 ppm |
| 2016-09-06 | 275428001 | 0.703 ppm |
| 2016-09-06 | 275428001 | 0.770 ppm |
| 2016-10-03 | 281374001 | 0.669 ppm |
| 2016-10-03 | 281374001 | 0.750 ppm |
| 2016-11-09 | 288658001 | 0.750 ppm |
| 2016-11-09 | 288658001 | 0.808 ppm |
| 2016-12-05 | 291049001 | 0.800 ppm |
| 2016-12-05 | 291049001 | 0.826 ppm |
| 2017-01-09 | 295294001 | 0.726 ppm |
| 2017-01-09 | 295294001 | 0.790 ppm |
| 2017-01-31 | 971663 | 0.0920 ppm |
| 2017-01-31 | 971661 | 0.0940 ppm |
| 2017-01-31 | 971658 | 0.110 ppm |
| 2017-01-31 | 971654 | 0.110 ppm |
| 2017-02-06 | 972336 | 0.110 ppm |
| 2017-02-20 | 300616001 | 0.778 ppm |
| 2017-02-20 | 300616001 | 0.810 ppm |
| 2017-03-13 | 303667001 | 0.780 ppm |
| 2017-03-13 | 303667001 | 0.810 ppm |
| 2017-04-06 | 308479001 | 0.742 ppm |
| 2017-04-06 | 308479001 | 0.760 ppm |
| 2017-05-04 | 314076001 | 0.674 ppm |
| 2017-05-04 | 314076001 | 0.780 ppm |
| 2017-06-19 | 322366001 | 0.745 ppm |
| 2017-06-19 | 322366001 | 0.830 ppm |
| 2017-07-02 | 325827001 | 0.780 ppm |
| 2017-07-02 | 325827001 | 0.783 ppm |
| 2017-08-07 | 333519001 | 0.720 ppm |
| 2017-08-07 | 333519001 | 0.728 ppm |
| 2017-09-01 | 339540001 | 0.770 ppm |
| 2017-09-01 | 339540001 | 0.818 ppm |
| 2017-10-02 | 346500001 | 0.777 ppm |
| 2017-10-02 | 346500001 | 0.800 ppm |
| 2017-11-06 | 352414001 | 0.800 ppm |
| 2017-11-06 | 352414001 | 0.826 ppm |
| 2017-12-01 | 357499001 | 0.790 ppm |
| 2017-12-01 | 357499001 | 0.835 ppm |
| 2018-01-04 | 361482001 | 0.800 ppm |
| 2018-01-04 | 361482001 | 0.836 ppm |
| 2018-02-05 | 365245001 | 0.800 ppm |
| 2018-02-05 | 365245001 | 0.810 ppm |
| 2018-03-05 | 369207001 | 0.780 ppm |
| 2018-03-05 | 369207001 | 0.788 ppm |
| 2018-04-16 | 376579001 | 0.730 ppm |
| 2018-04-16 | 376579001 | 0.819 ppm |
| 2018-05-07 | 381295001 | 0.750 ppm |
| 2018-05-07 | 381295001 | 0.800 ppm |
| 2018-06-20 | 390080001 | 0.700 ppm |
| 2018-06-20 | 390080001 | 0.708 ppm |
| 2018-07-02 | 391818001 | 0.730 ppm |
| 2018-07-02 | 391818001 | 0.793 ppm |
| 2018-08-02 | 399248001 | 0.820 ppm |
| 2018-08-02 | 399248001 | 0.927 ppm |
| 2018-09-01 | 404616001 | 0.755 ppm |
| 2018-09-01 | 404616001 | 0.790 ppm |
| 2018-10-01 | 412546001 | 0.800 ppm |
| 2018-10-01 | 412546001 | 0.857 ppm |
| 2018-11-12 | 419040001 | 0.740 ppm |
| 2018-11-12 | 419040001 | 0.774 ppm |
| 2018-12-02 | 421902001 | 0.776 ppm |
| 2018-12-02 | 421902001 | 0.780 ppm |
| 2019-01-01 | 425959001 | 0.770 ppm |
| 2019-01-01 | 425959001 | 0.773 ppm |
| 2019-02-11 | 430829001 | 0.750 ppm |
| 2019-02-11 | 430829001 | 0.766 ppm |
| 2019-03-03 | 433353001 | 0.736 ppm |
| 2019-03-03 | 433353001 | 0.780 ppm |
| 2019-04-03 | 438861001 | 0.750 ppm |
| 2019-04-03 | 438861001 | 0.754 ppm |
| 2019-05-01 | 443514001 | 0.750 ppm |
| 2019-05-01 | 443514001 | 0.788 ppm |
| 2019-06-06 | 450248001 | 0.687 ppm |
| 2019-06-06 | 450248001 | 0.710 ppm |
| 2019-07-02 | 455269001 | 0.737 ppm |
| 2019-07-02 | 455269001 | 0.750 ppm |
| 2019-08-06 | 462447001 | 0.757 ppm |
| 2019-08-06 | 462447001 | 0.780 ppm |
| 2019-09-02 | 466963001 | 0.799 ppm |
| 2019-09-02 | 466963001 | 0.800 ppm |
| 2019-10-02 | 474308001 | 0.790 ppm |
| 2019-10-02 | 474308001 | 0.815 ppm |
| 2019-11-10 | 480625001 | 0.689 ppm |
| 2019-11-10 | 480625001 | 0.730 ppm |
| 2019-12-02 | 483651001 | 0.760 ppm |
| 2019-12-02 | 483651001 | 0.824 ppm |