Fluoride
Green Bay 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 |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 0.967 ppm | 32 | 32 | 0.624 ppm - 2.90 ppm |
| 2015 | 0.748 ppm | 25 | 25 | 0.660 ppm - 0.800 ppm |
| 2016 | 0.713 ppm | 24 | 24 | 0.633 ppm - 0.860 ppm |
| 2017 | 0.693 ppm | 25 | 25 | 0.630 ppm - 0.780 ppm |
| 2018 | 0.721 ppm | 24 | 24 | 0.650 ppm - 0.790 ppm |
| 2019 | 0.675 ppm | 24 | 24 | 0.550 ppm - 0.770 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 |
|---|---|---|
| 2014-01-13 | 115924001 | 0.637 ppm |
| 2014-01-13 | 115924001 | 0.670 ppm |
| 2014-02-03 | 118175001 | 0.624 ppm |
| 2014-02-03 | 118175001 | 0.650 ppm |
| 2014-03-03 | 121615001 | 0.660 ppm |
| 2014-03-03 | 121615001 | 0.673 ppm |
| 2014-04-07 | 126323001 | 0.656 ppm |
| 2014-04-07 | 126323001 | 0.700 ppm |
| 2014-05-05 | 130583001 | 0.683 ppm |
| 2014-05-05 | 130583001 | 0.770 ppm |
| 2014-05-19 | 790051 | 0.690 ppm |
| 2014-05-19 | 790085 | 0.720 ppm |
| 2014-05-19 | 790060 | 1.70 ppm |
| 2014-05-19 | 790047 | 1.80 ppm |
| 2014-05-19 | 790056 | 1.80 ppm |
| 2014-05-19 | 790081 | 2.10 ppm |
| 2014-05-19 | 790077 | 2.70 ppm |
| 2014-05-19 | 790068 | 2.90 ppm |
| 2014-06-02 | 136179001 | 0.669 ppm |
| 2014-06-02 | 136179001 | 0.690 ppm |
| 2014-07-07 | 143595001 | 0.646 ppm |
| 2014-07-07 | 143595001 | 0.710 ppm |
| 2014-08-04 | 149155001 | 0.720 ppm |
| 2014-08-04 | 149155001 | 0.738 ppm |
| 2014-09-08 | 155547001 | 0.681 ppm |
| 2014-09-08 | 155547001 | 0.720 ppm |
| 2014-10-07 | 162476001 | 0.660 ppm |
| 2014-10-07 | 162476001 | 0.700 ppm |
| 2014-11-03 | 166754001 | 0.680 ppm |
| 2014-11-03 | 166754001 | 0.714 ppm |
| 2014-12-01 | 170345001 | 0.729 ppm |
| 2014-12-01 | 170345001 | 0.740 ppm |
| 2015-01-05 | 174306001 | 0.760 ppm |
| 2015-01-05 | 174306001 | 0.763 ppm |
| 2015-02-02 | 177807001 | 0.710 ppm |
| 2015-02-02 | 177807001 | 0.717 ppm |
| 2015-03-02 | 181433001 | 0.660 ppm |
| 2015-03-02 | 181433001 | 0.727 ppm |
| 2015-04-06 | 186404001 | 0.740 ppm |
| 2015-04-06 | 186404001 | 0.741 ppm |
| 2015-04-20 | 855003 | 0.770 ppm |
| 2015-05-04 | 191017001 | 0.750 ppm |
| 2015-05-04 | 191017001 | 0.770 ppm |
| 2015-06-01 | 197027001 | 0.764 ppm |
| 2015-06-01 | 197027001 | 0.800 ppm |
| 2015-07-06 | 203710001 | 0.780 ppm |
| 2015-07-06 | 203710001 | 0.797 ppm |
| 2015-08-04 | 209920001 | 0.757 ppm |
| 2015-08-04 | 209920001 | 0.800 ppm |
| 2015-09-08 | 216197001 | 0.744 ppm |
| 2015-09-08 | 216197001 | 0.790 ppm |
| 2015-10-07 | 222637001 | 0.722 ppm |
| 2015-10-07 | 222637001 | 0.730 ppm |
| 2015-11-02 | 226732001 | 0.690 ppm |
| 2015-11-02 | 226732001 | 0.755 ppm |
| 2015-12-07 | 231399001 | 0.710 ppm |
| 2015-12-07 | 231399001 | 0.741 ppm |
| 2016-01-04 | 234343001 | 0.750 ppm |
| 2016-01-04 | 234343001 | 0.860 ppm |
| 2016-02-23 | 241050001 | 0.747 ppm |
| 2016-02-23 | 241050001 | 0.830 ppm |
| 2016-03-07 | 242870001 | 0.730 ppm |
| 2016-03-07 | 242870001 | 0.765 ppm |
| 2016-04-04 | 246888001 | 0.690 ppm |
| 2016-04-04 | 246888001 | 0.739 ppm |
| 2016-05-02 | 251912001 | 0.736 ppm |
| 2016-05-02 | 251912001 | 0.770 ppm |
| 2016-06-06 | 258603001 | 0.730 ppm |
| 2016-06-06 | 258603001 | 0.745 ppm |
| 2016-07-11 | 265255001 | 0.633 ppm |
| 2016-07-11 | 265255001 | 0.650 ppm |
| 2016-08-01 | 269665001 | 0.655 ppm |
| 2016-08-01 | 269665001 | 0.680 ppm |
| 2016-09-06 | 275783001 | 0.657 ppm |
| 2016-09-06 | 275783001 | 0.670 ppm |
| 2016-10-03 | 281905001 | 0.659 ppm |
| 2016-10-03 | 281905001 | 0.660 ppm |
| 2016-11-07 | 287839001 | 0.690 ppm |
| 2016-11-07 | 287839001 | 0.693 ppm |
| 2016-12-05 | 291390001 | 0.660 ppm |
| 2016-12-05 | 291390001 | 0.708 ppm |
| 2017-01-03 | 294920001 | 0.663 ppm |
| 2017-01-03 | 294920001 | 0.700 ppm |
| 2017-02-06 | 298911001 | 0.678 ppm |
| 2017-02-06 | 298911001 | 0.700 ppm |
| 2017-03-14 | 304299001 | 0.670 ppm |
| 2017-03-14 | 304299001 | 0.680 ppm |
| 2017-04-03 | 307543001 | 0.650 ppm |
| 2017-04-03 | 307543001 | 0.681 ppm |
| 2017-04-24 | 984913 | 0.750 ppm |
| 2017-05-01 | 313092001 | 0.680 ppm |
| 2017-05-01 | 313092001 | 0.682 ppm |
| 2017-06-05 | 319805001 | 0.630 ppm |
| 2017-06-05 | 319805001 | 0.677 ppm |
| 2017-07-10 | 327330001 | 0.665 ppm |
| 2017-07-10 | 327330001 | 0.700 ppm |
| 2017-08-07 | 334026001 | 0.679 ppm |
| 2017-08-07 | 334026001 | 0.760 ppm |
| 2017-09-05 | 340107001 | 0.691 ppm |
| 2017-09-05 | 340107001 | 0.720 ppm |
| 2017-10-02 | 346428001 | 0.678 ppm |
| 2017-10-02 | 346428001 | 0.780 ppm |
| 2017-11-06 | 352809001 | 0.683 ppm |
| 2017-11-06 | 352809001 | 0.720 ppm |
| 2017-12-04 | 357398001 | 0.709 ppm |
| 2017-12-04 | 357398001 | 0.710 ppm |
| 2018-01-08 | 361957001 | 0.682 ppm |
| 2018-01-08 | 361957001 | 0.710 ppm |
| 2018-02-05 | 365622001 | 0.675 ppm |
| 2018-02-05 | 365622001 | 0.700 ppm |
| 2018-03-05 | 369617001 | 0.750 ppm |
| 2018-03-05 | 369617001 | 0.752 ppm |
| 2018-04-02 | 374167001 | 0.730 ppm |
| 2018-04-02 | 374167001 | 0.740 ppm |
| 2018-05-08 | 381019001 | 0.660 ppm |
| 2018-05-08 | 381019001 | 0.669 ppm |
| 2018-06-04 | 386149001 | 0.740 ppm |
| 2018-06-04 | 386149001 | 0.764 ppm |
| 2018-07-09 | 393044001 | 0.742 ppm |
| 2018-07-09 | 393044001 | 0.770 ppm |
| 2018-08-06 | 399144001 | 0.727 ppm |
| 2018-08-06 | 399144001 | 0.760 ppm |
| 2018-09-05 | 405130001 | 0.724 ppm |
| 2018-09-05 | 405130001 | 0.730 ppm |
| 2018-10-02 | 412265001 | 0.720 ppm |
| 2018-10-02 | 412265001 | 0.740 ppm |
| 2018-11-05 | 418083001 | 0.705 ppm |
| 2018-11-05 | 418083001 | 0.790 ppm |
| 2018-12-04 | 422714001 | 0.650 ppm |
| 2018-12-04 | 422714001 | 0.678 ppm |
| 2019-01-07 | 426618001 | 0.658 ppm |
| 2019-01-07 | 426618001 | 0.770 ppm |
| 2019-02-05 | 430418001 | 0.674 ppm |
| 2019-02-05 | 430418001 | 0.750 ppm |
| 2019-03-05 | 434071001 | 0.670 ppm |
| 2019-03-05 | 434071001 | 0.760 ppm |
| 2019-04-01 | 438137001 | 0.682 ppm |
| 2019-04-01 | 438137001 | 0.690 ppm |
| 2019-05-06 | 444374001 | 0.630 ppm |
| 2019-05-06 | 444374001 | 0.661 ppm |
| 2019-06-03 | 449442001 | 0.550 ppm |
| 2019-06-03 | 449442001 | 0.669 ppm |
| 2019-07-01 | 455196001 | 0.644 ppm |
| 2019-07-01 | 455196001 | 0.670 ppm |
| 2019-08-05 | 461745001 | 0.669 ppm |
| 2019-08-05 | 461745001 | 0.720 ppm |
| 2019-09-10 | 469404001 | 0.638 ppm |
| 2019-09-10 | 469404001 | 0.660 ppm |
| 2019-10-07 | 475050001 | 0.663 ppm |
| 2019-10-07 | 475050001 | 0.690 ppm |
| 2019-11-12 | 481245001 | 0.673 ppm |
| 2019-11-12 | 481245001 | 0.720 ppm |
| 2019-12-03 | 484318001 | 0.620 ppm |
| 2019-12-03 | 484318001 | 0.668 ppm |