Fluoride
Rothschild 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 | 0.702 ppm | 24 | 24 | 0.650 ppm - 0.760 ppm |
| 2019 | 0.713 ppm | 24 | 24 | 0.593 ppm - 0.874 ppm |
| 2020 | 0.663 ppm | 22 | 22 | 0.0490 ppm - 0.850 ppm |
| 2021 | 0.693 ppm | 28 | 28 | 0.607 ppm - 0.768 ppm |
| 2022 | 0.671 ppm | 24 | 24 | 0.611 ppm - 0.852 ppm |
| 2023 | 0.665 ppm | 26 | 26 | 0.170 ppm - 1.30 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 |
|---|---|---|
| 2018-01-09 | 362514001 | 0.730 ppm |
| 2018-01-09 | 362514001 | 0.752 ppm |
| 2018-02-01 | 365117001 | 0.700 ppm |
| 2018-02-01 | 365117001 | 0.700 ppm |
| 2018-03-01 | 369130001 | 0.710 ppm |
| 2018-03-01 | 369130001 | 0.751 ppm |
| 2018-04-05 | 374865001 | 0.680 ppm |
| 2018-04-05 | 374865001 | 0.760 ppm |
| 2018-05-07 | 381298001 | 0.690 ppm |
| 2018-05-07 | 381298001 | 0.731 ppm |
| 2018-06-07 | 387293001 | 0.688 ppm |
| 2018-06-07 | 387293001 | 0.700 ppm |
| 2018-07-09 | 393647001 | 0.700 ppm |
| 2018-07-09 | 393647001 | 0.714 ppm |
| 2018-08-02 | 398537001 | 0.680 ppm |
| 2018-08-02 | 398537001 | 0.680 ppm |
| 2018-09-05 | 407085001 | 0.661 ppm |
| 2018-09-05 | 407085001 | 0.710 ppm |
| 2018-10-03 | 412705001 | 0.730 ppm |
| 2018-10-03 | 412705001 | 0.734 ppm |
| 2018-11-12 | 419869001 | 0.650 ppm |
| 2018-11-12 | 419869001 | 0.664 ppm |
| 2018-12-04 | 423071001 | 0.665 ppm |
| 2018-12-04 | 423071001 | 0.670 ppm |
| 2019-01-07 | 427261001 | 0.593 ppm |
| 2019-01-07 | 427261001 | 0.680 ppm |
| 2019-02-08 | 430726001 | 0.710 ppm |
| 2019-02-08 | 430726001 | 0.770 ppm |
| 2019-03-05 | 434292001 | 0.684 ppm |
| 2019-03-05 | 434292001 | 0.690 ppm |
| 2019-04-16 | 441279001 | 0.658 ppm |
| 2019-04-16 | 441279001 | 0.700 ppm |
| 2019-05-07 | 445109001 | 0.740 ppm |
| 2019-05-07 | 445109001 | 0.874 ppm |
| 2019-06-11 | 451479001 | 0.690 ppm |
| 2019-06-11 | 451479001 | 0.847 ppm |
| 2019-07-02 | 455463001 | 0.605 ppm |
| 2019-07-02 | 455463001 | 0.670 ppm |
| 2019-08-07 | 462635001 | 0.680 ppm |
| 2019-08-07 | 462635001 | 0.693 ppm |
| 2019-09-02 | 467874001 | 0.690 ppm |
| 2019-09-02 | 467874001 | 0.732 ppm |
| 2019-10-08 | 475732001 | 0.750 ppm |
| 2019-10-08 | 475732001 | 0.773 ppm |
| 2019-11-06 | 480519001 | 0.680 ppm |
| 2019-11-06 | 480519001 | 0.777 ppm |
| 2019-12-03 | 484704001 | 0.700 ppm |
| 2019-12-03 | 484704001 | 0.734 ppm |
| 2020-01-10 | 488811001 | 0.640 ppm |
| 2020-01-10 | 488811001 | 0.850 ppm |
| 2020-04-08 | 500363001 | 0.683 ppm |
| 2020-04-08 | 500363001 | 0.700 ppm |
| 2020-05-04 | 503495001 | 0.690 ppm |
| 2020-05-04 | 503495001 | 0.782 ppm |
| 2020-06-03 | 508126001 | 0.690 ppm |
| 2020-06-03 | 508126001 | 0.829 ppm |
| 2020-07-06 | 513497001 | 0.680 ppm |
| 2020-07-06 | 513497001 | 0.714 ppm |
| 2020-08-05 | 518795001 | 0.670 ppm |
| 2020-08-05 | 518795001 | 0.748 ppm |
| 2020-08-10 | 1205734 | 0.0490 ppm |
| 2020-08-10 | 1205730 | 0.160 ppm |
| 2020-09-02 | 523645001 | 0.690 ppm |
| 2020-09-02 | 523645001 | 0.771 ppm |
| 2020-10-06 | 530155001 | 0.680 ppm |
| 2020-10-06 | 530155001 | 0.694 ppm |
| 2020-11-04 | 534936001 | 0.666 ppm |
| 2020-11-04 | 534936001 | 0.710 ppm |
| 2020-12-01 | 538613001 | 0.680 ppm |
| 2020-12-01 | 538613001 | 0.802 ppm |
| 2021-01-07 | 542893001 | 0.710 ppm |
| 2021-01-07 | 542893001 | 0.753 ppm |
| 2021-02-02 | 546516001 | 0.690 ppm |
| 2021-02-02 | 546516001 | 0.768 ppm |
| 2021-02-02 | 546516001 | 0.690 ppm |
| 2021-02-02 | 546516001 | 0.768 ppm |
| 2021-03-01 | 550050001 | 0.636 ppm |
| 2021-03-01 | 550050001 | 0.660 ppm |
| 2021-03-01 | 550050001 | 0.636 ppm |
| 2021-03-01 | 550050001 | 0.660 ppm |
| 2021-04-05 | 554612001 | 0.660 ppm |
| 2021-04-05 | 554612001 | 0.690 ppm |
| 2021-05-03 | 560158001 | 0.640 ppm |
| 2021-05-03 | 560158001 | 0.715 ppm |
| 2021-06-07 | 566115001 | 0.676 ppm |
| 2021-06-07 | 566115001 | 0.680 ppm |
| 2021-07-07 | 571302001 | 0.631 ppm |
| 2021-07-07 | 571302001 | 0.680 ppm |
| 2021-08-04 | 576686001 | 0.607 ppm |
| 2021-08-04 | 576686001 | 0.700 ppm |
| 2021-09-09 | 582786001 | 0.720 ppm |
| 2021-09-09 | 582786001 | 0.746 ppm |
| 2021-10-12 | 589449001 | 0.690 ppm |
| 2021-10-12 | 589449001 | 0.702 ppm |
| 2021-11-02 | 593192001 | 0.721 ppm |
| 2021-11-02 | 593192001 | 0.740 ppm |
| 2021-12-01 | 596793001 | 0.709 ppm |
| 2021-12-01 | 596793001 | 0.720 ppm |
| 2022-01-04 | 601001001 | 0.650 ppm |
| 2022-01-04 | 601001001 | 0.717 ppm |
| 2022-02-03 | 604554001 | 0.678 ppm |
| 2022-02-03 | 604554001 | 0.680 ppm |
| 2022-03-21 | 610890001 | 0.640 ppm |
| 2022-03-21 | 610890001 | 0.852 ppm |
| 2022-04-04 | 612936001 | 0.636 ppm |
| 2022-04-04 | 612936001 | 0.690 ppm |
| 2022-05-02 | 617517001 | 0.614 ppm |
| 2022-05-02 | 617517001 | 0.680 ppm |
| 2022-06-02 | 622923001 | 0.630 ppm |
| 2022-06-02 | 622923001 | 0.650 ppm |
| 2022-07-06 | 629356001 | 0.611 ppm |
| 2022-07-06 | 629356001 | 0.660 ppm |
| 2022-08-02 | 635050001 | 0.640 ppm |
| 2022-08-02 | 635050001 | 0.700 ppm |
| 2022-09-07 | 641481001 | 0.690 ppm |
| 2022-09-07 | 641481001 | 0.720 ppm |
| 2022-10-06 | 647360001 | 0.640 ppm |
| 2022-10-06 | 647360001 | 0.669 ppm |
| 2022-11-07 | 652583001 | 0.641 ppm |
| 2022-11-07 | 652583001 | 0.680 ppm |
| 2022-12-06 | 656187001 | 0.662 ppm |
| 2022-12-06 | 656187001 | 0.670 ppm |
| 2023-01-09 | 660679001 | 0.700 ppm |
| 2023-01-09 | 660679001 | 0.706 ppm |
| 2023-02-01 | 663007001 | 0.686 ppm |
| 2023-02-01 | 663007001 | 0.740 ppm |
| 2023-03-01 | 666653001 | 0.690 ppm |
| 2023-03-01 | 666653001 | 0.700 ppm |
| 2023-04-04 | 671865001 | 0.651 ppm |
| 2023-04-04 | 671865001 | 0.710 ppm |
| 2023-05-01 | 676484001 | 0.670 ppm |
| 2023-05-01 | 676484001 | 0.680 ppm |
| 2023-05-22 | CB05354-01 | 1.30 ppm |
| 2023-06-07 | 682910001 | 0.690 ppm |
| 2023-06-07 | 682910001 | 0.762 ppm |
| 2023-07-12 | 689015001 | 0.629 ppm |
| 2023-07-12 | 689015001 | 0.690 ppm |
| 2023-08-01 | 692825001 | 0.591 ppm |
| 2023-08-01 | 692825001 | 0.730 ppm |
| 2023-08-28 | CB10306-01 | 0.170 ppm |
| 2023-09-06 | 699172001 | 0.557 ppm |
| 2023-09-06 | 699172001 | 0.680 ppm |
| 2023-10-03 | 704735001 | 0.576 ppm |
| 2023-10-03 | 704735001 | 0.640 ppm |
| 2023-11-13 | 711230001 | 0.515 ppm |
| 2023-11-13 | 711230001 | 0.640 ppm |
| 2023-12-04 | 714003001 | 0.553 ppm |
| 2023-12-04 | 714003001 | 0.630 ppm |