Fluoride
Tomahawk Waterworks
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems to prevent cavities and support oral health in people.
In 2015, the Department of Health and Human Services updated its recommendation of an optimal level of 0.7 parts per million, or ppm, added to drinking water based on the health benefits of tooth decay prevention. Studies have shown that fluoride added to community water systems at this level reduces dental cavities, especially in children.
And studies have conclusively shown that fluoride in toothpaste and mouthwash can also provide these benefits.
Read More.
Health Concerns
Although the HHS-recommended level of 0.7 ppm can help promote oral health in children and adults, this level is likely too high for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water.
And fluoride in water at higher levels can be detrimental for everyone, especially children.
Long-term ingestion of higher levels of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth in children.
A 2024 authoritative assessment by the National Toxicology Program found that higher levels of fluoride exposure, such as drinking water containing more than 1.5 ppm of fluoride, are associated with lower IQ in children. The conclusion was based on studies in human populations outside of the U.S.
Affecting systems with naturally occurring fluoride, 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 fracture. But these effects may occur at lower levels of exposure, raising concerns that the current limit may not adequately protect public health.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 0.634 ppm | 24 | 24 | 0.581 ppm - 0.690 ppm |
| 2019 | 0.675 ppm | 24 | 24 | 0.552 ppm - 1.000 ppm |
| 2020 | 0.664 ppm | 20 | 20 | 0.538 ppm - 0.770 ppm |
| 2021 | 0.565 ppm | 28 | 28 | 0.0816 ppm - 0.720 ppm |
| 2022 | 0.502 ppm | 24 | 24 | 0.410 ppm - 0.670 ppm |
| 2023 | 0.362 ppm | 26 | 26 | 0.0407 ppm - 0.720 ppm |
ppm = parts per million
State, National, and Health Guidelines for Drinking Water
EPA Maximum Contaminant
Level (MCL): 4 ppm
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-01-29 | 364814001 | 0.650 ppm |
| 2018-01-29 | 364814001 | 0.670 ppm |
| 2018-02-27 | 368860001 | 0.588 ppm |
| 2018-02-27 | 368860001 | 0.650 ppm |
| 2018-03-28 | 373484001 | 0.581 ppm |
| 2018-03-28 | 373484001 | 0.690 ppm |
| 2018-04-24 | 378378001 | 0.614 ppm |
| 2018-04-24 | 378378001 | 0.620 ppm |
| 2018-05-21 | 384159001 | 0.619 ppm |
| 2018-05-21 | 384159001 | 0.630 ppm |
| 2018-06-26 | 391204001 | 0.610 ppm |
| 2018-06-26 | 391204001 | 0.627 ppm |
| 2018-07-23 | 396423001 | 0.620 ppm |
| 2018-07-23 | 396423001 | 0.642 ppm |
| 2018-08-07 | 399721001 | 0.630 ppm |
| 2018-08-07 | 399721001 | 0.646 ppm |
| 2018-09-05 | 405653001 | 0.616 ppm |
| 2018-09-05 | 405653001 | 0.620 ppm |
| 2018-10-02 | 412252001 | 0.640 ppm |
| 2018-10-02 | 412252001 | 0.662 ppm |
| 2018-11-05 | 418100001 | 0.640 ppm |
| 2018-11-05 | 418100001 | 0.653 ppm |
| 2018-12-04 | 422720001 | 0.630 ppm |
| 2018-12-04 | 422720001 | 0.656 ppm |
| 2019-01-07 | 426619001 | 0.630 ppm |
| 2019-01-07 | 426619001 | 0.644 ppm |
| 2019-02-05 | 430406001 | 0.630 ppm |
| 2019-02-05 | 430406001 | 0.675 ppm |
| 2019-03-05 | 434110001 | 0.675 ppm |
| 2019-03-05 | 434110001 | 0.740 ppm |
| 2019-04-02 | 438578001 | 0.658 ppm |
| 2019-04-02 | 438578001 | 0.690 ppm |
| 2019-05-08 | 445115001 | 0.655 ppm |
| 2019-05-08 | 445115001 | 0.800 ppm |
| 2019-06-05 | 450209001 | 0.760 ppm |
| 2019-06-05 | 450209001 | 1.000 ppm |
| 2019-07-08 | 456246001 | 0.570 ppm |
| 2019-07-08 | 456246001 | 0.593 ppm |
| 2019-08-05 | 461696001 | 0.552 ppm |
| 2019-08-05 | 461696001 | 0.580 ppm |
| 2019-09-04 | 467872001 | 0.622 ppm |
| 2019-09-04 | 467872001 | 0.650 ppm |
| 2019-10-09 | 475730001 | 0.658 ppm |
| 2019-10-09 | 475730001 | 0.660 ppm |
| 2019-11-05 | 480122001 | 0.650 ppm |
| 2019-11-05 | 480122001 | 0.664 ppm |
| 2019-12-04 | 484592001 | 0.711 ppm |
| 2019-12-04 | 484592001 | 0.740 ppm |
| 2020-01-15 | 489691001 | 0.610 ppm |
| 2020-01-15 | 489691001 | 0.770 ppm |
| 2020-04-06 | 499784001 | 0.632 ppm |
| 2020-04-06 | 499784001 | 0.750 ppm |
| 2020-05-05 | 503497001 | 0.538 ppm |
| 2020-05-05 | 503497001 | 0.720 ppm |
| 2020-06-02 | 507813001 | 0.590 ppm |
| 2020-06-02 | 507813001 | 0.680 ppm |
| 2020-07-06 | 513127001 | 0.639 ppm |
| 2020-07-06 | 513127001 | 0.660 ppm |
| 2020-08-03 | 518079001 | 0.580 ppm |
| 2020-08-03 | 518079001 | 0.612 ppm |
| 2020-09-02 | 523449001 | 0.670 ppm |
| 2020-09-02 | 523449001 | 0.715 ppm |
| 2020-10-06 | 529936001 | 0.684 ppm |
| 2020-10-06 | 529936001 | 0.770 ppm |
| 2020-11-02 | 534337001 | 0.650 ppm |
| 2020-11-02 | 534337001 | 0.662 ppm |
| 2020-12-01 | 538405001 | 0.667 ppm |
| 2020-12-01 | 538405001 | 0.680 ppm |
| 2021-01-11 | 543290001 | 0.690 ppm |
| 2021-01-11 | 543290001 | 0.700 ppm |
| 2021-02-01 | 545928001 | 0.473 ppm |
| 2021-02-01 | 545928001 | 0.720 ppm |
| 2021-02-01 | 545928001 | 0.473 ppm |
| 2021-02-01 | 545928001 | 0.720 ppm |
| 2021-03-09 | 551195001 | 0.460 ppm |
| 2021-03-09 | 551195001 | 0.482 ppm |
| 2021-03-09 | 551195001 | 0.460 ppm |
| 2021-03-09 | 551195001 | 0.482 ppm |
| 2021-04-07 | 555277001 | 0.588 ppm |
| 2021-04-07 | 555277001 | 0.710 ppm |
| 2021-05-05 | 560370001 | 0.580 ppm |
| 2021-05-05 | 560370001 | 0.700 ppm |
| 2021-06-01 | 564688001 | 0.580 ppm |
| 2021-06-01 | 564688001 | 0.630 ppm |
| 2021-07-06 | 570830001 | 0.600 ppm |
| 2021-07-06 | 570830001 | 0.640 ppm |
| 2021-08-03 | 576280001 | 0.570 ppm |
| 2021-08-03 | 576280001 | 0.633 ppm |
| 2021-09-07 | 582204001 | 0.531 ppm |
| 2021-09-07 | 582204001 | 0.540 ppm |
| 2021-10-06 | 588454001 | 0.560 ppm |
| 2021-10-06 | 588454001 | 0.630 ppm |
| 2021-11-01 | 592543001 | 0.477 ppm |
| 2021-11-01 | 592543001 | 0.490 ppm |
| 2021-12-06 | 597302001 | 0.0816 ppm |
| 2021-12-06 | 597302001 | 0.630 ppm |
| 2022-01-10 | 601463001 | 0.430 ppm |
| 2022-01-10 | 601463001 | 0.459 ppm |
| 2022-02-08 | 605234001 | 0.592 ppm |
| 2022-02-08 | 605234001 | 0.670 ppm |
| 2022-03-08 | 608908001 | 0.520 ppm |
| 2022-03-08 | 608908001 | 0.607 ppm |
| 2022-04-19 | 615045001 | 0.430 ppm |
| 2022-04-19 | 615045001 | 0.472 ppm |
| 2022-05-03 | 617534001 | 0.440 ppm |
| 2022-05-03 | 617534001 | 0.524 ppm |
| 2022-06-13 | 625011001 | 0.514 ppm |
| 2022-06-13 | 625011001 | 0.540 ppm |
| 2022-07-06 | 629078001 | 0.460 ppm |
| 2022-07-06 | 629078001 | 0.514 ppm |
| 2022-08-01 | 634386001 | 0.460 ppm |
| 2022-08-01 | 634386001 | 0.493 ppm |
| 2022-09-12 | 642078001 | 0.410 ppm |
| 2022-09-12 | 642078001 | 0.439 ppm |
| 2022-10-03 | 646488001 | 0.438 ppm |
| 2022-10-03 | 646488001 | 0.560 ppm |
| 2022-11-07 | 652254001 | 0.431 ppm |
| 2022-11-07 | 652254001 | 0.550 ppm |
| 2022-12-07 | 656377001 | 0.456 ppm |
| 2022-12-07 | 656377001 | 0.630 ppm |
| 2023-01-03 | 659305001 | 0.475 ppm |
| 2023-01-03 | 659305001 | 0.520 ppm |
| 2023-02-07 | 663989001 | 0.472 ppm |
| 2023-02-07 | 663989001 | 0.600 ppm |
| 2023-03-07 | 667701001 | 0.485 ppm |
| 2023-03-07 | 667701001 | 0.720 ppm |
| 2023-04-03 | 671636001 | 0.482 ppm |
| 2023-04-03 | 671636001 | 0.530 ppm |
| 2023-04-18 | CB03729-04 | 0.0570 ppm |
| 2023-04-18 | CB03729-01 | 0.0590 ppm |
| 2023-05-02 | 676675001 | 0.608 ppm |
| 2023-05-02 | 676675001 | 0.630 ppm |
| 2023-06-06 | 682682001 | 0.0407 ppm |
| 2023-06-06 | 682682001 | 0.580 ppm |
| 2023-07-10 | 688255001 | 0.0417 ppm |
| 2023-07-10 | 688255001 | 0.330 ppm |
| 2023-08-07 | 693851001 | 0.0523 ppm |
| 2023-08-07 | 693851001 | 0.340 ppm |
| 2023-09-12 | 700254001 | 0.180 ppm |
| 2023-09-12 | 700254001 | 0.208 ppm |
| 2023-10-03 | 704432001 | 0.249 ppm |
| 2023-10-03 | 704432001 | 0.450 ppm |
| 2023-11-07 | 710322001 | 0.230 ppm |
| 2023-11-07 | 710322001 | 0.440 ppm |
| 2023-12-05 | 713886001 | 0.160 ppm |
| 2023-12-05 | 713886001 | 0.483 ppm |