Fluoride
Schofield 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 | 0.686 ppm | 27 | 27 | 0.0990 ppm - 0.840 ppm |
| 2015 | 0.692 ppm | 24 | 24 | 0.615 ppm - 0.822 ppm |
| 2016 | 0.690 ppm | 24 | 24 | 0.615 ppm - 0.767 ppm |
| 2017 | 0.644 ppm | 27 | 27 | 0.0720 ppm - 0.862 ppm |
| 2018 | 0.725 ppm | 24 | 24 | 0.512 ppm - 0.837 ppm |
| 2019 | 0.685 ppm | 24 | 24 | 0.421 ppm - 0.871 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 | 116041001 | 0.700 ppm |
| 2014-01-13 | 116041001 | 0.753 ppm |
| 2014-02-05 | 118836001 | 0.746 ppm |
| 2014-02-05 | 118836001 | 0.780 ppm |
| 2014-02-10 | 769671 | 0.0990 ppm |
| 2014-02-10 | 769669 | 0.140 ppm |
| 2014-02-10 | 769667 | 0.840 ppm |
| 2014-03-04 | 121936001 | 0.690 ppm |
| 2014-03-04 | 121936001 | 0.753 ppm |
| 2014-04-07 | 126574001 | 0.670 ppm |
| 2014-04-07 | 126574001 | 0.708 ppm |
| 2014-05-06 | 130756001 | 0.730 ppm |
| 2014-05-06 | 130756001 | 0.756 ppm |
| 2014-06-06 | 137512001 | 0.654 ppm |
| 2014-06-06 | 137512001 | 0.680 ppm |
| 2014-07-10 | 144641001 | 0.700 ppm |
| 2014-07-10 | 144641001 | 0.765 ppm |
| 2014-08-14 | 151578001 | 0.700 ppm |
| 2014-08-14 | 151578001 | 0.802 ppm |
| 2014-09-17 | 158396001 | 0.675 ppm |
| 2014-09-17 | 158396001 | 0.680 ppm |
| 2014-10-01 | 161023001 | 0.730 ppm |
| 2014-10-01 | 161023001 | 0.789 ppm |
| 2014-11-17 | 169080001 | 0.730 ppm |
| 2014-11-17 | 169080001 | 0.772 ppm |
| 2014-12-22 | 173633001 | 0.685 ppm |
| 2014-12-22 | 173633001 | 0.807 ppm |
| 2015-01-20 | 176535001 | 0.615 ppm |
| 2015-01-20 | 176535001 | 0.657 ppm |
| 2015-02-04 | 178426001 | 0.680 ppm |
| 2015-02-04 | 178426001 | 0.715 ppm |
| 2015-03-11 | 183309001 | 0.700 ppm |
| 2015-03-11 | 183309001 | 0.729 ppm |
| 2015-04-14 | 188232001 | 0.710 ppm |
| 2015-04-14 | 188232001 | 0.720 ppm |
| 2015-05-07 | 192189001 | 0.717 ppm |
| 2015-05-07 | 192189001 | 0.720 ppm |
| 2015-06-09 | 199214001 | 0.710 ppm |
| 2015-06-09 | 199214001 | 0.822 ppm |
| 2015-07-13 | 205312001 | 0.644 ppm |
| 2015-07-13 | 205312001 | 0.685 ppm |
| 2015-08-13 | 211802001 | 0.622 ppm |
| 2015-08-13 | 211802001 | 0.695 ppm |
| 2015-09-15 | 217924001 | 0.624 ppm |
| 2015-09-15 | 217924001 | 0.669 ppm |
| 2015-10-14 | 223998001 | 0.658 ppm |
| 2015-10-14 | 223998001 | 0.708 ppm |
| 2015-11-17 | 229344001 | 0.757 ppm |
| 2015-11-17 | 229344001 | 0.767 ppm |
| 2015-12-09 | 232232001 | 0.624 ppm |
| 2015-12-09 | 232232001 | 0.653 ppm |
| 2016-01-13 | 235932001 | 0.630 ppm |
| 2016-01-13 | 235932001 | 0.681 ppm |
| 2016-02-18 | 240435001 | 0.693 ppm |
| 2016-02-18 | 240435001 | 0.765 ppm |
| 2016-03-15 | 244639001 | 0.615 ppm |
| 2016-03-15 | 244639001 | 0.719 ppm |
| 2016-04-14 | 248889001 | 0.631 ppm |
| 2016-04-14 | 248889001 | 0.639 ppm |
| 2016-05-16 | 255352001 | 0.645 ppm |
| 2016-05-16 | 255352001 | 0.700 ppm |
| 2016-06-13 | 260134001 | 0.700 ppm |
| 2016-06-13 | 260134001 | 0.725 ppm |
| 2016-07-18 | 266994001 | 0.655 ppm |
| 2016-07-18 | 266994001 | 0.713 ppm |
| 2016-08-15 | 272276001 | 0.653 ppm |
| 2016-08-15 | 272276001 | 0.668 ppm |
| 2016-09-14 | 278163001 | 0.762 ppm |
| 2016-09-14 | 278163001 | 0.767 ppm |
| 2016-10-17 | 284497001 | 0.722 ppm |
| 2016-10-17 | 284497001 | 0.748 ppm |
| 2016-11-16 | 289642001 | 0.670 ppm |
| 2016-11-16 | 289642001 | 0.682 ppm |
| 2016-12-14 | 293256001 | 0.661 ppm |
| 2016-12-14 | 293256001 | 0.713 ppm |
| 2017-01-18 | 296785001 | 0.724 ppm |
| 2017-01-18 | 296785001 | 0.739 ppm |
| 2017-02-14 | 300270001 | 0.600 ppm |
| 2017-02-14 | 300270001 | 0.677 ppm |
| 2017-03-13 | 303889001 | 0.742 ppm |
| 2017-03-13 | 303889001 | 0.784 ppm |
| 2017-04-12 | 309667001 | 0.763 ppm |
| 2017-04-12 | 309667001 | 0.767 ppm |
| 2017-05-16 | 316412001 | 0.730 ppm |
| 2017-05-16 | 316412001 | 0.743 ppm |
| 2017-06-20 | 999043 | 0.0810 ppm |
| 2017-06-21 | 323771001 | 0.640 ppm |
| 2017-06-21 | 323771001 | 0.655 ppm |
| 2017-07-17 | 329671001 | 0.706 ppm |
| 2017-07-17 | 329671001 | 0.717 ppm |
| 2017-08-15 | 336296001 | 0.733 ppm |
| 2017-08-15 | 336296001 | 0.757 ppm |
| 2017-08-16 | 1011907 | 0.0720 ppm |
| 2017-08-16 | 1011905 | 0.230 ppm |
| 2017-09-20 | 344075001 | 0.615 ppm |
| 2017-09-20 | 344075001 | 0.641 ppm |
| 2017-10-16 | 349337001 | 0.669 ppm |
| 2017-10-16 | 349337001 | 0.862 ppm |
| 2017-11-15 | 354945001 | 0.691 ppm |
| 2017-11-15 | 354945001 | 0.714 ppm |
| 2017-12-19 | 360251001 | 0.585 ppm |
| 2017-12-19 | 360251001 | 0.739 ppm |
| 2018-01-17 | 363373001 | 0.687 ppm |
| 2018-01-17 | 363373001 | 0.792 ppm |
| 2018-02-13 | 367048001 | 0.669 ppm |
| 2018-02-13 | 367048001 | 0.723 ppm |
| 2018-03-21 | 372597001 | 0.715 ppm |
| 2018-03-21 | 372597001 | 0.725 ppm |
| 2018-04-18 | 377262001 | 0.726 ppm |
| 2018-04-18 | 377262001 | 0.801 ppm |
| 2018-05-16 | 382959001 | 0.766 ppm |
| 2018-05-16 | 382959001 | 0.776 ppm |
| 2018-06-13 | 388776001 | 0.763 ppm |
| 2018-06-13 | 388776001 | 0.764 ppm |
| 2018-07-18 | 395862001 | 0.681 ppm |
| 2018-07-18 | 395862001 | 0.691 ppm |
| 2018-08-15 | 401700001 | 0.727 ppm |
| 2018-08-15 | 401700001 | 0.810 ppm |
| 2018-09-18 | 409301001 | 0.674 ppm |
| 2018-09-18 | 409301001 | 0.717 ppm |
| 2018-10-24 | 416449001 | 0.715 ppm |
| 2018-10-24 | 416449001 | 0.797 ppm |
| 2018-11-14 | 420318001 | 0.637 ppm |
| 2018-11-14 | 420318001 | 0.837 ppm |
| 2018-12-19 | 425513001 | 0.512 ppm |
| 2018-12-19 | 425513001 | 0.703 ppm |
| 2019-01-22 | 428936001 | 0.505 ppm |
| 2019-01-22 | 428936001 | 0.631 ppm |
| 2019-02-19 | 432629001 | 0.503 ppm |
| 2019-02-19 | 432629001 | 0.636 ppm |
| 2019-03-19 | 436609001 | 0.577 ppm |
| 2019-03-19 | 436609001 | 0.700 ppm |
| 2019-04-23 | 442404001 | 0.747 ppm |
| 2019-04-23 | 442404001 | 0.800 ppm |
| 2019-05-13 | 446250001 | 0.636 ppm |
| 2019-05-13 | 446250001 | 0.680 ppm |
| 2019-06-20 | 453350001 | 0.838 ppm |
| 2019-06-20 | 453350001 | 0.871 ppm |
| 2019-07-10 | 457229001 | 0.768 ppm |
| 2019-07-10 | 457229001 | 0.777 ppm |
| 2019-08-20 | 465501001 | 0.745 ppm |
| 2019-08-20 | 465501001 | 0.781 ppm |
| 2019-09-16 | 471027001 | 0.708 ppm |
| 2019-09-16 | 471027001 | 0.717 ppm |
| 2019-10-28 | 478808001 | 0.421 ppm |
| 2019-10-28 | 478808001 | 0.632 ppm |
| 2019-11-19 | 482848001 | 0.675 ppm |
| 2019-11-19 | 482848001 | 0.677 ppm |
| 2019-12-12 | 486400001 | 0.682 ppm |
| 2019-12-12 | 486400001 | 0.724 ppm |