Fluoride
Dickeyville 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 | 0.874 ppm | 24 | 24 | 0.490 ppm - 1.52 ppm |
| 2019 | 0.830 ppm | 24 | 24 | 0.583 ppm - 1.000 ppm |
| 2020 | 0.805 ppm | 20 | 20 | 0.523 ppm - 1.12 ppm |
| 2021 | 0.776 ppm | 28 | 28 | 0.566 ppm - 0.950 ppm |
| 2022 | 0.744 ppm | 24 | 24 | 0.230 ppm - 0.870 ppm |
| 2023 | 0.772 ppm | 24 | 24 | 0.650 ppm - 0.920 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 |
|---|---|---|
| 2018-01-08 | 361967001 | 0.545 ppm |
| 2018-01-08 | 361967001 | 0.630 ppm |
| 2018-02-12 | 366683001 | 0.576 ppm |
| 2018-02-12 | 366683001 | 0.720 ppm |
| 2018-03-07 | 370205001 | 1.24 ppm |
| 2018-03-07 | 370205001 | 1.38 ppm |
| 2018-04-09 | 375392001 | 0.623 ppm |
| 2018-04-09 | 375392001 | 0.670 ppm |
| 2018-05-15 | 382734001 | 1.02 ppm |
| 2018-05-15 | 382734001 | 1.17 ppm |
| 2018-06-04 | 386148001 | 0.690 ppm |
| 2018-06-04 | 386148001 | 0.790 ppm |
| 2018-07-09 | 393033001 | 0.926 ppm |
| 2018-07-09 | 393033001 | 1.01 ppm |
| 2018-08-14 | 401233001 | 1.39 ppm |
| 2018-08-14 | 401233001 | 1.52 ppm |
| 2018-09-10 | 406628001 | 0.731 ppm |
| 2018-09-10 | 406628001 | 0.820 ppm |
| 2018-10-04 | 412689001 | 0.813 ppm |
| 2018-10-04 | 412689001 | 0.880 ppm |
| 2018-11-05 | 418125001 | 0.490 ppm |
| 2018-11-05 | 418125001 | 0.563 ppm |
| 2018-12-03 | 422328001 | 0.824 ppm |
| 2018-12-03 | 422328001 | 0.960 ppm |
| 2019-01-02 | 425958001 | 0.981 ppm |
| 2019-01-02 | 425958001 | 0.990 ppm |
| 2019-02-19 | 432330001 | 0.843 ppm |
| 2019-02-19 | 432330001 | 0.870 ppm |
| 2019-03-06 | 434233001 | 0.852 ppm |
| 2019-03-06 | 434233001 | 0.930 ppm |
| 2019-04-10 | 440034001 | 0.583 ppm |
| 2019-04-10 | 440034001 | 0.590 ppm |
| 2019-05-06 | 444379001 | 0.903 ppm |
| 2019-05-06 | 444379001 | 1.000 ppm |
| 2019-06-03 | 449428001 | 0.691 ppm |
| 2019-06-03 | 449428001 | 0.780 ppm |
| 2019-07-08 | 456240001 | 0.778 ppm |
| 2019-07-08 | 456240001 | 0.880 ppm |
| 2019-08-07 | 462446001 | 0.690 ppm |
| 2019-08-07 | 462446001 | 0.715 ppm |
| 2019-09-04 | 467849001 | 0.696 ppm |
| 2019-09-04 | 467849001 | 0.950 ppm |
| 2019-10-02 | 474306001 | 0.811 ppm |
| 2019-10-02 | 474306001 | 0.820 ppm |
| 2019-11-05 | 480035001 | 0.846 ppm |
| 2019-11-05 | 480035001 | 0.980 ppm |
| 2019-12-02 | 483909001 | 0.831 ppm |
| 2019-12-02 | 483909001 | 0.910 ppm |
| 2020-01-07 | 488445001 | 0.860 ppm |
| 2020-01-07 | 488445001 | 0.861 ppm |
| 2020-04-07 | 500204001 | 0.709 ppm |
| 2020-04-07 | 500204001 | 0.800 ppm |
| 2020-05-06 | 503663001 | 0.800 ppm |
| 2020-05-06 | 503663001 | 0.859 ppm |
| 2020-06-02 | 507808001 | 0.842 ppm |
| 2020-06-02 | 507808001 | 1.04 ppm |
| 2020-07-01 | 512559001 | 0.619 ppm |
| 2020-07-01 | 512559001 | 0.710 ppm |
| 2020-08-04 | 518332001 | 0.654 ppm |
| 2020-08-04 | 518332001 | 0.770 ppm |
| 2020-09-02 | 523433001 | 0.791 ppm |
| 2020-09-02 | 523433001 | 0.950 ppm |
| 2020-10-05 | 529502001 | 0.806 ppm |
| 2020-10-05 | 529502001 | 0.820 ppm |
| 2020-11-02 | 534298001 | 1.000 ppm |
| 2020-11-02 | 534298001 | 1.12 ppm |
| 2020-12-01 | 538340001 | 0.523 ppm |
| 2020-12-01 | 538340001 | 0.570 ppm |
| 2021-01-04 | 542121001 | 0.566 ppm |
| 2021-01-04 | 542121001 | 0.700 ppm |
| 2021-02-01 | 545868001 | 0.690 ppm |
| 2021-02-01 | 545868001 | 0.770 ppm |
| 2021-02-01 | 545868001 | 0.690 ppm |
| 2021-02-01 | 545868001 | 0.770 ppm |
| 2021-03-02 | 549894001 | 0.815 ppm |
| 2021-03-02 | 549894001 | 0.880 ppm |
| 2021-03-02 | 549894001 | 0.815 ppm |
| 2021-03-02 | 549894001 | 0.880 ppm |
| 2021-04-05 | 554607001 | 0.786 ppm |
| 2021-04-05 | 554607001 | 0.950 ppm |
| 2021-05-03 | 559762001 | 0.760 ppm |
| 2021-05-03 | 559762001 | 0.820 ppm |
| 2021-06-01 | 564612001 | 0.737 ppm |
| 2021-06-01 | 564612001 | 0.870 ppm |
| 2021-07-06 | 570817001 | 0.727 ppm |
| 2021-07-06 | 570817001 | 0.760 ppm |
| 2021-08-02 | 575820001 | 0.704 ppm |
| 2021-08-02 | 575820001 | 0.820 ppm |
| 2021-09-07 | 582229001 | 0.750 ppm |
| 2021-09-07 | 582229001 | 0.870 ppm |
| 2021-10-04 | 587739001 | 0.673 ppm |
| 2021-10-04 | 587739001 | 0.720 ppm |
| 2021-11-02 | 592865001 | 0.665 ppm |
| 2021-11-02 | 592865001 | 0.790 ppm |
| 2021-12-06 | 597211001 | 0.811 ppm |
| 2021-12-06 | 597211001 | 0.940 ppm |
| 2022-01-11 | 601723001 | 0.747 ppm |
| 2022-01-11 | 601723001 | 0.830 ppm |
| 2022-02-01 | 604175001 | 0.721 ppm |
| 2022-02-01 | 604175001 | 0.750 ppm |
| 2022-03-01 | 607690001 | 0.757 ppm |
| 2022-03-01 | 607690001 | 0.810 ppm |
| 2022-04-11 | 613937001 | 0.230 ppm |
| 2022-04-11 | 613937001 | 0.702 ppm |
| 2022-05-02 | 617112001 | 0.700 ppm |
| 2022-05-02 | 617112001 | 0.732 ppm |
| 2022-06-06 | 623544001 | 0.743 ppm |
| 2022-06-06 | 623544001 | 0.800 ppm |
| 2022-07-05 | 628672001 | 0.683 ppm |
| 2022-07-05 | 628672001 | 0.780 ppm |
| 2022-08-01 | 634318001 | 0.754 ppm |
| 2022-08-01 | 634318001 | 0.870 ppm |
| 2022-09-06 | 641004001 | 0.736 ppm |
| 2022-09-06 | 641004001 | 0.850 ppm |
| 2022-10-17 | 649001001 | 0.726 ppm |
| 2022-10-17 | 649001001 | 0.740 ppm |
| 2022-11-02 | 651580001 | 0.734 ppm |
| 2022-11-02 | 651580001 | 0.860 ppm |
| 2022-12-05 | 655696001 | 0.740 ppm |
| 2022-12-05 | 655696001 | 0.870 ppm |
| 2023-01-03 | 659238001 | 0.736 ppm |
| 2023-01-03 | 659238001 | 0.770 ppm |
| 2023-02-07 | 663754001 | 0.706 ppm |
| 2023-02-07 | 663754001 | 0.770 ppm |
| 2023-03-01 | 666460001 | 0.729 ppm |
| 2023-03-01 | 666460001 | 0.760 ppm |
| 2023-04-03 | 671616001 | 0.746 ppm |
| 2023-04-03 | 671616001 | 0.870 ppm |
| 2023-05-01 | 676039001 | 0.740 ppm |
| 2023-05-01 | 676039001 | 0.810 ppm |
| 2023-06-06 | 682465001 | 0.688 ppm |
| 2023-06-06 | 682465001 | 0.720 ppm |
| 2023-07-11 | 688439001 | 0.720 ppm |
| 2023-07-11 | 688439001 | 0.729 ppm |
| 2023-08-08 | 693842001 | 0.650 ppm |
| 2023-08-08 | 693842001 | 0.734 ppm |
| 2023-09-12 | 699985001 | 0.743 ppm |
| 2023-09-12 | 699985001 | 0.840 ppm |
| 2023-10-18 | 707169001 | 0.748 ppm |
| 2023-10-18 | 707169001 | 0.760 ppm |
| 2023-11-06 | 709911001 | 0.880 ppm |
| 2023-11-06 | 709911001 | 0.898 ppm |
| 2023-12-05 | 713532001 | 0.863 ppm |
| 2023-12-05 | 713532001 | 0.920 ppm |