Fluoride
Marinette 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 | 0.783 ppm | 25 | 25 | 0.577 ppm - 1.19 ppm |
| 2015 | 0.728 ppm | 24 | 24 | 0.567 ppm - 0.793 ppm |
| 2016 | 0.726 ppm | 24 | 24 | 0.650 ppm - 0.797 ppm |
| 2017 | 0.696 ppm | 25 | 25 | 0.634 ppm - 0.800 ppm |
| 2018 | 0.704 ppm | 24 | 24 | 0.659 ppm - 0.771 ppm |
| 2019 | 0.707 ppm | 24 | 24 | 0.666 ppm - 0.760 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 | 115603001 | 1.14 ppm |
| 2014-01-08 | 115603001 | 1.19 ppm |
| 2014-02-05 | 118865001 | 0.988 ppm |
| 2014-02-05 | 118865001 | 1.01 ppm |
| 2014-03-05 | 122250001 | 0.983 ppm |
| 2014-03-05 | 122250001 | 1.03 ppm |
| 2014-04-02 | 777900 | 0.660 ppm |
| 2014-04-02 | 126092001 | 0.740 ppm |
| 2014-04-02 | 126092001 | 0.762 ppm |
| 2014-05-07 | 131538001 | 0.651 ppm |
| 2014-05-07 | 131538001 | 0.720 ppm |
| 2014-06-05 | 137384001 | 0.660 ppm |
| 2014-06-05 | 137384001 | 0.676 ppm |
| 2014-07-01 | 142790001 | 0.706 ppm |
| 2014-07-01 | 142790001 | 0.710 ppm |
| 2014-08-04 | 149744001 | 0.650 ppm |
| 2014-08-04 | 149744001 | 0.702 ppm |
| 2014-09-02 | 155201001 | 0.680 ppm |
| 2014-09-02 | 155201001 | 0.689 ppm |
| 2014-10-06 | 162473001 | 0.710 ppm |
| 2014-10-06 | 162473001 | 0.721 ppm |
| 2014-11-03 | 167161001 | 0.577 ppm |
| 2014-11-03 | 167161001 | 0.700 ppm |
| 2014-12-01 | 170956001 | 0.750 ppm |
| 2014-12-01 | 170956001 | 0.758 ppm |
| 2015-01-05 | 174453001 | 0.700 ppm |
| 2015-01-05 | 174453001 | 0.726 ppm |
| 2015-02-02 | 178325001 | 0.717 ppm |
| 2015-02-02 | 178325001 | 0.750 ppm |
| 2015-03-02 | 181869001 | 0.567 ppm |
| 2015-03-02 | 181869001 | 0.610 ppm |
| 2015-04-06 | 186512001 | 0.728 ppm |
| 2015-04-06 | 186512001 | 0.790 ppm |
| 2015-05-04 | 191278001 | 0.710 ppm |
| 2015-05-04 | 191278001 | 0.717 ppm |
| 2015-06-01 | 197089001 | 0.727 ppm |
| 2015-06-01 | 197089001 | 0.776 ppm |
| 2015-07-06 | 203727001 | 0.683 ppm |
| 2015-07-06 | 203727001 | 0.700 ppm |
| 2015-08-10 | 211288001 | 0.709 ppm |
| 2015-08-10 | 211288001 | 0.728 ppm |
| 2015-09-08 | 216563001 | 0.781 ppm |
| 2015-09-08 | 216563001 | 0.785 ppm |
| 2015-10-05 | 221951001 | 0.739 ppm |
| 2015-10-05 | 221951001 | 0.757 ppm |
| 2015-11-02 | 226743001 | 0.783 ppm |
| 2015-11-02 | 226743001 | 0.793 ppm |
| 2015-12-16 | 233204001 | 0.744 ppm |
| 2015-12-16 | 233204001 | 0.757 ppm |
| 2016-01-18 | 236452001 | 0.723 ppm |
| 2016-01-18 | 236452001 | 0.750 ppm |
| 2016-02-01 | 238206001 | 0.710 ppm |
| 2016-02-01 | 238206001 | 0.774 ppm |
| 2016-03-14 | 244452001 | 0.762 ppm |
| 2016-03-14 | 244452001 | 0.797 ppm |
| 2016-04-04 | 246886001 | 0.701 ppm |
| 2016-04-04 | 246886001 | 0.742 ppm |
| 2016-05-02 | 252401001 | 0.689 ppm |
| 2016-05-02 | 252401001 | 0.763 ppm |
| 2016-06-06 | 258587001 | 0.694 ppm |
| 2016-06-06 | 258587001 | 0.750 ppm |
| 2016-07-11 | 265415001 | 0.745 ppm |
| 2016-07-11 | 265415001 | 0.774 ppm |
| 2016-08-01 | 269337001 | 0.690 ppm |
| 2016-08-01 | 269337001 | 0.702 ppm |
| 2016-09-12 | 277144001 | 0.680 ppm |
| 2016-09-12 | 277144001 | 0.689 ppm |
| 2016-10-03 | 281860001 | 0.650 ppm |
| 2016-10-03 | 281860001 | 0.697 ppm |
| 2016-11-07 | 287619001 | 0.690 ppm |
| 2016-11-07 | 287619001 | 0.704 ppm |
| 2016-12-05 | 291833001 | 0.770 ppm |
| 2016-12-05 | 291833001 | 0.783 ppm |
| 2017-01-09 | 295858001 | 0.730 ppm |
| 2017-01-09 | 295858001 | 0.735 ppm |
| 2017-02-06 | 298905001 | 0.720 ppm |
| 2017-02-06 | 298905001 | 0.725 ppm |
| 2017-03-06 | 303366001 | 0.690 ppm |
| 2017-03-06 | 303366001 | 0.713 ppm |
| 2017-04-03 | 307963001 | 0.695 ppm |
| 2017-04-03 | 307963001 | 0.710 ppm |
| 2017-04-12 | 982812 | 0.800 ppm |
| 2017-05-01 | 313885001 | 0.690 ppm |
| 2017-05-01 | 313885001 | 0.703 ppm |
| 2017-06-05 | 320270001 | 0.663 ppm |
| 2017-06-05 | 320270001 | 0.670 ppm |
| 2017-07-11 | 327930001 | 0.644 ppm |
| 2017-07-11 | 327930001 | 0.650 ppm |
| 2017-08-07 | 334540001 | 0.634 ppm |
| 2017-08-07 | 334540001 | 0.660 ppm |
| 2017-09-11 | 341383001 | 0.692 ppm |
| 2017-09-11 | 341383001 | 0.700 ppm |
| 2017-10-09 | 348287001 | 0.712 ppm |
| 2017-10-09 | 348287001 | 0.716 ppm |
| 2017-11-06 | 353526001 | 0.672 ppm |
| 2017-11-06 | 353526001 | 0.694 ppm |
| 2017-12-04 | 357394001 | 0.678 ppm |
| 2017-12-04 | 357394001 | 0.702 ppm |
| 2018-01-08 | 361981001 | 0.670 ppm |
| 2018-01-08 | 361981001 | 0.699 ppm |
| 2018-02-12 | 366677001 | 0.684 ppm |
| 2018-02-12 | 366677001 | 0.710 ppm |
| 2018-03-12 | 371192001 | 0.713 ppm |
| 2018-03-12 | 371192001 | 0.740 ppm |
| 2018-04-09 | 375816001 | 0.691 ppm |
| 2018-04-09 | 375816001 | 0.720 ppm |
| 2018-05-16 | 382954001 | 0.698 ppm |
| 2018-05-16 | 382954001 | 0.710 ppm |
| 2018-06-11 | 387591001 | 0.680 ppm |
| 2018-06-11 | 387591001 | 0.696 ppm |
| 2018-07-16 | 394804001 | 0.710 ppm |
| 2018-07-16 | 394804001 | 0.771 ppm |
| 2018-08-13 | 400774001 | 0.730 ppm |
| 2018-08-13 | 400774001 | 0.739 ppm |
| 2018-09-10 | 407089001 | 0.710 ppm |
| 2018-09-10 | 407089001 | 0.713 ppm |
| 2018-10-08 | 413604001 | 0.681 ppm |
| 2018-10-08 | 413604001 | 0.690 ppm |
| 2018-11-05 | 418560001 | 0.659 ppm |
| 2018-11-05 | 418560001 | 0.680 ppm |
| 2018-12-03 | 422859001 | 0.698 ppm |
| 2018-12-03 | 422859001 | 0.710 ppm |
| 2019-01-07 | 427269001 | 0.696 ppm |
| 2019-01-07 | 427269001 | 0.720 ppm |
| 2019-02-04 | 429991001 | 0.700 ppm |
| 2019-02-04 | 429991001 | 0.730 ppm |
| 2019-03-11 | 435223001 | 0.693 ppm |
| 2019-03-11 | 435223001 | 0.720 ppm |
| 2019-04-08 | 439436001 | 0.683 ppm |
| 2019-04-08 | 439436001 | 0.700 ppm |
| 2019-05-06 | 444370001 | 0.740 ppm |
| 2019-05-06 | 444370001 | 0.760 ppm |
| 2019-06-03 | 449427001 | 0.727 ppm |
| 2019-06-03 | 449427001 | 0.730 ppm |
| 2019-07-08 | 456721001 | 0.710 ppm |
| 2019-07-08 | 456721001 | 0.710 ppm |
| 2019-08-05 | 461735001 | 0.680 ppm |
| 2019-08-05 | 461735001 | 0.707 ppm |
| 2019-09-09 | 468737001 | 0.710 ppm |
| 2019-09-09 | 468737001 | 0.710 ppm |
| 2019-10-07 | 475452001 | 0.666 ppm |
| 2019-10-07 | 475452001 | 0.700 ppm |
| 2019-11-04 | 480009001 | 0.670 ppm |
| 2019-11-04 | 480009001 | 0.671 ppm |
| 2019-12-02 | 483932001 | 0.720 ppm |
| 2019-12-02 | 483932001 | 0.725 ppm |