Fluoride
Edgar 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 | 0.642 ppm | 26 | 25 | ND - 0.780 ppm |
| 2015 | 0.709 ppm | 24 | 24 | 0.660 ppm - 0.800 ppm |
| 2016 | 0.675 ppm | 24 | 24 | 0.506 ppm - 0.800 ppm |
| 2017 | 0.556 ppm | 26 | 26 | 0.0900 ppm - 0.824 ppm |
| 2018 | 0.633 ppm | 24 | 24 | 0.422 ppm - 0.780 ppm |
| 2019 | 0.688 ppm | 24 | 24 | 0.610 ppm - 0.812 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 |
|---|---|---|
| 2014-01-09 | 115639001 | 0.690 ppm |
| 2014-01-09 | 115639001 | 0.694 ppm |
| 2014-02-26 | 121081001 | 0.658 ppm |
| 2014-02-26 | 121081001 | 0.700 ppm |
| 2014-03-12 | 123316001 | 0.779 ppm |
| 2014-03-12 | 123316001 | 0.780 ppm |
| 2014-04-30 | 129903001 | 0.716 ppm |
| 2014-04-30 | 129903001 | 0.750 ppm |
| 2014-05-09 | 131574001 | 0.680 ppm |
| 2014-05-09 | 131574001 | 0.683 ppm |
| 2014-06-18 | 140394001 | 0.733 ppm |
| 2014-06-18 | 140394001 | 0.740 ppm |
| 2014-06-23 | 4060828-02 | ND |
| 2014-06-23 | 4060828-01 | 0.130 ppm |
| 2014-07-30 | 148395001 | 0.640 ppm |
| 2014-07-30 | 148395001 | 0.656 ppm |
| 2014-08-15 | 152013001 | 0.631 ppm |
| 2014-08-15 | 152013001 | 0.670 ppm |
| 2014-09-03 | 154876001 | 0.631 ppm |
| 2014-09-03 | 154876001 | 0.640 ppm |
| 2014-10-22 | 165414001 | 0.680 ppm |
| 2014-10-22 | 165414001 | 0.685 ppm |
| 2014-11-20 | 169619001 | 0.685 ppm |
| 2014-11-20 | 169619001 | 0.690 ppm |
| 2014-12-04 | 171223001 | 0.660 ppm |
| 2014-12-04 | 171223001 | 0.702 ppm |
| 2015-01-07 | 174854001 | 0.700 ppm |
| 2015-01-07 | 174854001 | 0.721 ppm |
| 2015-02-23 | 180625001 | 0.762 ppm |
| 2015-02-23 | 180625001 | 0.790 ppm |
| 2015-03-13 | 183450001 | 0.698 ppm |
| 2015-03-13 | 183450001 | 0.710 ppm |
| 2015-04-28 | 190314001 | 0.664 ppm |
| 2015-04-28 | 190314001 | 0.700 ppm |
| 2015-05-05 | 191767001 | 0.704 ppm |
| 2015-05-05 | 191767001 | 0.730 ppm |
| 2015-06-24 | 201932001 | 0.673 ppm |
| 2015-06-24 | 201932001 | 0.720 ppm |
| 2015-07-08 | 204514001 | 0.680 ppm |
| 2015-07-08 | 204514001 | 0.730 ppm |
| 2015-08-10 | 210669001 | 0.706 ppm |
| 2015-08-10 | 210669001 | 0.800 ppm |
| 2015-09-17 | 219124001 | 0.667 ppm |
| 2015-09-17 | 219124001 | 0.740 ppm |
| 2015-10-29 | 226168001 | 0.664 ppm |
| 2015-10-29 | 226168001 | 0.720 ppm |
| 2015-11-24 | 230087001 | 0.663 ppm |
| 2015-11-24 | 230087001 | 0.740 ppm |
| 2015-12-02 | 230883001 | 0.660 ppm |
| 2015-12-02 | 230883001 | 0.683 ppm |
| 2016-01-21 | 236730001 | 0.643 ppm |
| 2016-01-21 | 236730001 | 0.750 ppm |
| 2016-02-29 | 241528001 | 0.728 ppm |
| 2016-02-29 | 241528001 | 0.800 ppm |
| 2016-03-09 | 243483001 | 0.772 ppm |
| 2016-03-09 | 243483001 | 0.800 ppm |
| 2016-04-21 | 250092001 | 0.576 ppm |
| 2016-04-21 | 250092001 | 0.650 ppm |
| 2016-05-11 | 254061001 | 0.639 ppm |
| 2016-05-11 | 254061001 | 0.700 ppm |
| 2016-06-13 | 260789001 | 0.623 ppm |
| 2016-06-13 | 260789001 | 0.690 ppm |
| 2016-07-06 | 264651001 | 0.696 ppm |
| 2016-07-06 | 264651001 | 0.770 ppm |
| 2016-08-04 | 270431001 | 0.751 ppm |
| 2016-08-04 | 270431001 | 0.800 ppm |
| 2016-09-26 | 280403001 | 0.619 ppm |
| 2016-09-26 | 280403001 | 0.660 ppm |
| 2016-10-06 | 283864001 | 0.557 ppm |
| 2016-10-06 | 283864001 | 0.620 ppm |
| 2016-11-29 | 290601001 | 0.606 ppm |
| 2016-11-29 | 290601001 | 0.640 ppm |
| 2016-12-13 | 293108001 | 0.506 ppm |
| 2016-12-13 | 293108001 | 0.600 ppm |
| 2017-01-05 | 295188001 | 0.760 ppm |
| 2017-01-05 | 295188001 | 0.800 ppm |
| 2017-02-09 | 299887001 | 0.693 ppm |
| 2017-02-09 | 299887001 | 0.750 ppm |
| 2017-03-20 | 306051001 | 0.503 ppm |
| 2017-03-20 | 306051001 | 0.600 ppm |
| 2017-04-06 | 309454001 | 0.582 ppm |
| 2017-04-06 | 309454001 | 0.620 ppm |
| 2017-05-25 | 318344001 | 0.595 ppm |
| 2017-05-25 | 318344001 | 0.640 ppm |
| 2017-06-12 | 321321001 | 0.464 ppm |
| 2017-06-12 | 321321001 | 0.500 ppm |
| 2017-06-20 | 17F0831-01 | 0.130 ppm |
| 2017-06-21 | 17F0895-01 | 0.0900 ppm |
| 2017-07-31 | 332294001 | 0.532 ppm |
| 2017-07-31 | 332294001 | 0.610 ppm |
| 2017-08-14 | 336304001 | 0.482 ppm |
| 2017-08-14 | 336304001 | 0.600 ppm |
| 2017-09-28 | 345695001 | 0.357 ppm |
| 2017-09-28 | 345695001 | 0.450 ppm |
| 2017-10-26 | 351296001 | 0.544 ppm |
| 2017-10-26 | 351296001 | 0.600 ppm |
| 2017-11-03 | 352271001 | 0.800 ppm |
| 2017-11-03 | 352271001 | 0.824 ppm |
| 2017-12-06 | 358082001 | 0.421 ppm |
| 2017-12-06 | 358082001 | 0.520 ppm |
| 2018-01-09 | 362354001 | 0.436 ppm |
| 2018-01-09 | 362354001 | 0.500 ppm |
| 2018-02-08 | 366209001 | 0.422 ppm |
| 2018-02-08 | 366209001 | 0.460 ppm |
| 2018-03-08 | 370310001 | 0.613 ppm |
| 2018-03-08 | 370310001 | 0.650 ppm |
| 2018-04-12 | 376323001 | 0.688 ppm |
| 2018-04-12 | 376323001 | 0.770 ppm |
| 2018-05-30 | 385398001 | 0.643 ppm |
| 2018-05-30 | 385398001 | 0.730 ppm |
| 2018-06-25 | 391201001 | 0.695 ppm |
| 2018-06-25 | 391201001 | 0.780 ppm |
| 2018-07-12 | 394193001 | 0.680 ppm |
| 2018-07-12 | 394193001 | 0.760 ppm |
| 2018-08-13 | 400768001 | 0.667 ppm |
| 2018-08-13 | 400768001 | 0.700 ppm |
| 2018-09-11 | 407172001 | 0.666 ppm |
| 2018-09-11 | 407172001 | 0.700 ppm |
| 2018-10-10 | 414068001 | 0.546 ppm |
| 2018-10-10 | 414068001 | 0.600 ppm |
| 2018-11-28 | 421684001 | 0.656 ppm |
| 2018-11-28 | 421684001 | 0.690 ppm |
| 2018-12-21 | 425526001 | 0.532 ppm |
| 2018-12-21 | 425526001 | 0.600 ppm |
| 2019-01-31 | 429586001 | 0.620 ppm |
| 2019-01-31 | 429586001 | 0.645 ppm |
| 2019-02-18 | 432570001 | 0.677 ppm |
| 2019-02-18 | 432570001 | 0.680 ppm |
| 2019-03-08 | 434425001 | 0.703 ppm |
| 2019-03-08 | 434425001 | 0.730 ppm |
| 2019-04-17 | 441404001 | 0.610 ppm |
| 2019-04-17 | 441404001 | 0.620 ppm |
| 2019-05-09 | 445298001 | 0.657 ppm |
| 2019-05-09 | 445298001 | 0.680 ppm |
| 2019-06-10 | 450994001 | 0.680 ppm |
| 2019-06-10 | 450994001 | 0.687 ppm |
| 2019-07-10 | 457037001 | 0.790 ppm |
| 2019-07-10 | 457037001 | 0.812 ppm |
| 2019-08-15 | 464225001 | 0.630 ppm |
| 2019-08-15 | 464225001 | 0.642 ppm |
| 2019-09-10 | 469395001 | 0.670 ppm |
| 2019-09-10 | 469395001 | 0.689 ppm |
| 2019-10-09 | 475734001 | 0.670 ppm |
| 2019-10-09 | 475734001 | 0.705 ppm |
| 2019-11-19 | 482843001 | 0.700 ppm |
| 2019-11-19 | 482843001 | 0.775 ppm |
| 2019-12-05 | 484765001 | 0.700 ppm |
| 2019-12-05 | 484765001 | 0.741 ppm |