Fluoride
La Crosse 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 | 0.560 ppm | 35 | 30 | ND - 0.910 ppm |
| 2015 | 0.707 ppm | 24 | 24 | 0.671 ppm - 0.796 ppm |
| 2016 | 0.707 ppm | 24 | 24 | 0.644 ppm - 0.786 ppm |
| 2017 | 0.635 ppm | 35 | 35 | 0.0900 ppm - 1.77 ppm |
| 2018 | 0.712 ppm | 24 | 24 | 0.679 ppm - 0.777 ppm |
| 2019 | 0.700 ppm | 24 | 24 | 0.672 ppm - 0.728 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 |
|---|---|---|
| 2014-01-22 | 117462001 | 0.700 ppm |
| 2014-01-22 | 117462001 | 0.721 ppm |
| 2014-02-17 | 119973001 | 0.700 ppm |
| 2014-02-17 | 119973001 | 0.749 ppm |
| 2014-02-25 | 4020695-01 | 0.170 ppm |
| 2014-03-06 | 4030179-02 | ND |
| 2014-03-10 | 4030238-02 | ND |
| 2014-03-10 | 4030238-01 | 0.440 ppm |
| 2014-03-17 | 124052001 | 0.700 ppm |
| 2014-03-17 | 124052001 | 0.714 ppm |
| 2014-04-23 | 129057001 | 0.645 ppm |
| 2014-04-23 | 129057001 | 0.700 ppm |
| 2014-05-22 | 134700001 | 0.649 ppm |
| 2014-05-22 | 134700001 | 0.700 ppm |
| 2014-06-11 | 4060407-03 | ND |
| 2014-06-11 | 4060407-02 | 0.150 ppm |
| 2014-06-11 | 4060407-01 | 0.800 ppm |
| 2014-06-11 | 4060407-04 | 0.910 ppm |
| 2014-06-16 | 4060519-04 | ND |
| 2014-06-19 | 140547001 | 0.700 ppm |
| 2014-06-19 | 140547001 | 0.717 ppm |
| 2014-06-24 | 4060840-01 | ND |
| 2014-07-21 | 147065001 | 0.700 ppm |
| 2014-07-21 | 147065001 | 0.700 ppm |
| 2014-08-11 | 4080309-01 | 0.180 ppm |
| 2014-08-21 | 153076001 | 0.700 ppm |
| 2014-08-21 | 153076001 | 0.800 ppm |
| 2014-09-16 | 158397001 | 0.693 ppm |
| 2014-09-16 | 158397001 | 0.700 ppm |
| 2014-10-20 | 165008001 | 0.700 ppm |
| 2014-10-20 | 165008001 | 0.761 ppm |
| 2014-11-18 | 169552001 | 0.695 ppm |
| 2014-11-18 | 169552001 | 0.700 ppm |
| 2014-12-16 | 173308001 | 0.700 ppm |
| 2014-12-16 | 173308001 | 0.702 ppm |
| 2015-01-21 | 176922001 | 0.700 ppm |
| 2015-01-21 | 176922001 | 0.705 ppm |
| 2015-02-17 | 180354001 | 0.698 ppm |
| 2015-02-17 | 180354001 | 0.700 ppm |
| 2015-03-18 | 184441001 | 0.700 ppm |
| 2015-03-18 | 184441001 | 0.716 ppm |
| 2015-04-23 | 189765001 | 0.671 ppm |
| 2015-04-23 | 189765001 | 0.700 ppm |
| 2015-05-27 | 196293001 | 0.683 ppm |
| 2015-05-27 | 196293001 | 0.700 ppm |
| 2015-06-18 | 200953001 | 0.700 ppm |
| 2015-06-18 | 200953001 | 0.796 ppm |
| 2015-07-22 | 207723001 | 0.699 ppm |
| 2015-07-22 | 207723001 | 0.700 ppm |
| 2015-08-20 | 213157001 | 0.700 ppm |
| 2015-08-20 | 213157001 | 0.724 ppm |
| 2015-09-16 | 218327001 | 0.697 ppm |
| 2015-09-16 | 218327001 | 0.700 ppm |
| 2015-10-14 | 224161001 | 0.700 ppm |
| 2015-10-14 | 224161001 | 0.731 ppm |
| 2015-11-18 | 229698001 | 0.700 ppm |
| 2015-11-18 | 229698001 | 0.733 ppm |
| 2015-12-16 | 233381001 | 0.700 ppm |
| 2015-12-16 | 233381001 | 0.711 ppm |
| 2016-01-21 | 237074001 | 0.700 ppm |
| 2016-01-21 | 237074001 | 0.708 ppm |
| 2016-02-24 | 241280001 | 0.700 ppm |
| 2016-02-24 | 241280001 | 0.727 ppm |
| 2016-03-23 | 245594001 | 0.700 ppm |
| 2016-03-23 | 245594001 | 0.716 ppm |
| 2016-04-20 | 250093001 | 0.644 ppm |
| 2016-04-20 | 250093001 | 0.700 ppm |
| 2016-05-24 | 256702001 | 0.700 ppm |
| 2016-05-24 | 256702001 | 0.786 ppm |
| 2016-06-27 | 263289001 | 0.700 ppm |
| 2016-06-27 | 263289001 | 0.732 ppm |
| 2016-07-25 | 268714001 | 0.700 ppm |
| 2016-07-25 | 268714001 | 0.720 ppm |
| 2016-08-17 | 273060001 | 0.700 ppm |
| 2016-08-17 | 273060001 | 0.705 ppm |
| 2016-09-14 | 278140001 | 0.686 ppm |
| 2016-09-14 | 278140001 | 0.700 ppm |
| 2016-10-27 | 286324001 | 0.700 ppm |
| 2016-10-27 | 286324001 | 0.734 ppm |
| 2016-11-17 | 289781001 | 0.700 ppm |
| 2016-11-17 | 289781001 | 0.737 ppm |
| 2016-12-12 | 293375001 | 0.669 ppm |
| 2016-12-12 | 293375001 | 0.700 ppm |
| 2017-01-18 | 296921001 | 0.673 ppm |
| 2017-01-18 | 296921001 | 0.700 ppm |
| 2017-02-16 | 300571001 | 0.694 ppm |
| 2017-02-16 | 300571001 | 0.700 ppm |
| 2017-03-08 | 17C0300-01 | 0.0900 ppm |
| 2017-03-15 | 17C0533-01 | 0.130 ppm |
| 2017-03-16 | 17C0605-01 | 0.610 ppm |
| 2017-03-28 | 306583001 | 0.700 ppm |
| 2017-03-28 | 306583001 | 0.703 ppm |
| 2017-04-20 | 311277001 | 0.691 ppm |
| 2017-04-20 | 311277001 | 0.700 ppm |
| 2017-05-15 | 316409001 | 0.691 ppm |
| 2017-05-15 | 316409001 | 0.700 ppm |
| 2017-06-19 | 323473001 | 0.700 ppm |
| 2017-06-19 | 323473001 | 0.720 ppm |
| 2017-06-21 | 17F0857-03 | 0.1000 ppm |
| 2017-06-21 | 17F0857-01 | 0.140 ppm |
| 2017-06-21 | 17F0857-02 | 1.19 ppm |
| 2017-06-22 | 17F0900-01 | 0.290 ppm |
| 2017-06-26 | 17F0985-01 | 1.77 ppm |
| 2017-06-28 | 17F1145-01 | 0.130 ppm |
| 2017-06-28 | 17F1145-02 | 0.690 ppm |
| 2017-07-18 | 330225001 | 0.690 ppm |
| 2017-07-18 | 330225001 | 0.700 ppm |
| 2017-08-16 | 17H0739-01 | 0.140 ppm |
| 2017-08-24 | 338220001 | 0.697 ppm |
| 2017-08-24 | 338220001 | 0.700 ppm |
| 2017-09-25 | 345541001 | 0.700 ppm |
| 2017-09-25 | 345541001 | 0.703 ppm |
| 2017-10-24 | 351168001 | 0.700 ppm |
| 2017-10-24 | 351168001 | 0.762 ppm |
| 2017-11-15 | 355797001 | 0.700 ppm |
| 2017-11-15 | 355797001 | 0.732 ppm |
| 2017-12-26 | 360795001 | 0.704 ppm |
| 2017-12-26 | 360795001 | 0.800 ppm |
| 2018-01-22 | 364072001 | 0.700 ppm |
| 2018-01-22 | 364072001 | 0.718 ppm |
| 2018-02-15 | 367488001 | 0.679 ppm |
| 2018-02-15 | 367488001 | 0.700 ppm |
| 2018-03-19 | 372300001 | 0.700 ppm |
| 2018-03-19 | 372300001 | 0.731 ppm |
| 2018-04-19 | 377317001 | 0.700 ppm |
| 2018-04-19 | 377317001 | 0.717 ppm |
| 2018-05-17 | 383209001 | 0.700 ppm |
| 2018-05-17 | 383209001 | 0.750 ppm |
| 2018-06-20 | 390402001 | 0.691 ppm |
| 2018-06-20 | 390402001 | 0.700 ppm |
| 2018-07-18 | 395700001 | 0.700 ppm |
| 2018-07-18 | 395700001 | 0.777 ppm |
| 2018-08-20 | 402653001 | 0.700 ppm |
| 2018-08-20 | 402653001 | 0.736 ppm |
| 2018-09-20 | 409595001 | 0.700 ppm |
| 2018-09-20 | 409595001 | 0.728 ppm |
| 2018-10-24 | 416601001 | 0.693 ppm |
| 2018-10-24 | 416601001 | 0.700 ppm |
| 2018-11-26 | 421702001 | 0.700 ppm |
| 2018-11-26 | 421702001 | 0.742 ppm |
| 2018-12-12 | 424348001 | 0.700 ppm |
| 2018-12-12 | 424348001 | 0.730 ppm |
| 2019-01-22 | 428898001 | 0.700 ppm |
| 2019-01-22 | 428898001 | 0.710 ppm |
| 2019-02-27 | 433227001 | 0.700 ppm |
| 2019-02-27 | 433227001 | 0.706 ppm |
| 2019-03-20 | 436762001 | 0.684 ppm |
| 2019-03-20 | 436762001 | 0.700 ppm |
| 2019-04-22 | 441829001 | 0.700 ppm |
| 2019-04-22 | 441829001 | 0.719 ppm |
| 2019-05-20 | 447526001 | 0.700 ppm |
| 2019-05-20 | 447526001 | 0.711 ppm |
| 2019-06-13 | 451887001 | 0.700 ppm |
| 2019-06-13 | 451887001 | 0.709 ppm |
| 2019-07-24 | 459916001 | 0.690 ppm |
| 2019-07-24 | 459916001 | 0.700 ppm |
| 2019-08-19 | 465502001 | 0.700 ppm |
| 2019-08-19 | 465502001 | 0.701 ppm |
| 2019-09-19 | 471591001 | 0.673 ppm |
| 2019-09-19 | 471591001 | 0.700 ppm |
| 2019-10-23 | 478099001 | 0.700 ppm |
| 2019-10-23 | 478099001 | 0.705 ppm |
| 2019-11-14 | 481738001 | 0.672 ppm |
| 2019-11-14 | 481738001 | 0.700 ppm |
| 2019-12-11 | 486018001 | 0.700 ppm |
| 2019-12-11 | 486018001 | 0.728 ppm |