Know Your Environment. Protect Your Health.

Fluoride

Williams Bay 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.

 

146

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.711 ppm24240.430 ppm - 0.830 ppm
20190.743 ppm24240.630 ppm - 0.830 ppm
20200.710 ppm21210.520 ppm - 0.910 ppm
20210.714 ppm28280.570 ppm - 0.833 ppm
20220.650 ppm24240.530 ppm - 0.835 ppm
20230.722 ppm25250.605 ppm - 0.963 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
2018-01-253644530010.800 ppm
2018-01-253644530010.802 ppm
2018-02-143670630010.731 ppm
2018-02-143670630010.740 ppm
2018-03-123708180010.430 ppm
2018-03-123708180010.720 ppm
2018-04-023747200010.620 ppm
2018-04-023747200010.680 ppm
2018-05-093813040010.762 ppm
2018-05-093813040010.830 ppm
2018-06-263912030010.760 ppm
2018-06-263912030010.770 ppm
2018-07-173952600010.750 ppm
2018-07-173952600010.770 ppm
2018-08-274037930010.660 ppm
2018-08-274037930010.767 ppm
2018-09-244105740010.670 ppm
2018-09-244105740010.795 ppm
2018-10-154146560010.560 ppm
2018-10-154146560010.719 ppm
2018-11-144203110010.650 ppm
2018-11-144203110010.766 ppm
2018-12-034223820010.590 ppm
2018-12-034223820010.723 ppm
2019-01-084272560010.730 ppm
2019-01-084272560010.744 ppm
2019-02-194323270010.818 ppm
2019-02-194323270010.820 ppm
2019-03-254373590010.778 ppm
2019-03-254373590010.790 ppm
2019-04-154406890010.649 ppm
2019-04-154406890010.660 ppm
2019-05-284484240010.685 ppm
2019-05-284484240010.700 ppm
2019-06-124514780010.768 ppm
2019-06-124514780010.820 ppm
2019-07-244599500010.630 ppm
2019-07-244599500010.712 ppm
2019-08-264664360010.770 ppm
2019-08-264664360010.790 ppm
2019-09-234721290010.730 ppm
2019-09-234721290010.830 ppm
2019-10-214775320010.710 ppm
2019-10-214775320010.754 ppm
2019-11-184825610010.730 ppm
2019-11-184825610010.741 ppm
2019-12-184871930010.700 ppm
2019-12-184871930010.784 ppm
2020-01-224906400010.630 ppm
2020-01-224906400010.723 ppm
2020-04-145010790010.520 ppm
2020-04-145010790010.731 ppm
2020-05-135048230010.560 ppm
2020-05-135048230010.806 ppm
2020-06-1511934960.660 ppm
2020-06-155102450010.842 ppm
2020-06-155102450010.910 ppm
2020-07-135148660010.710 ppm
2020-07-135148660010.736 ppm
2020-08-185208880010.520 ppm
2020-08-185208880010.785 ppm
2020-09-085243070010.740 ppm
2020-09-085243070010.797 ppm
2020-10-125315350010.520 ppm
2020-10-125315350010.745 ppm
2020-11-165369010010.630 ppm
2020-11-165369010010.759 ppm
2020-12-095399750010.750 ppm
2020-12-095399750010.834 ppm
2021-01-205447420010.650 ppm
2021-01-205447420010.720 ppm
2021-02-225485200010.765 ppm
2021-02-225485200010.830 ppm
2021-02-225485200010.765 ppm
2021-02-225485200010.830 ppm
2021-03-105515590010.690 ppm
2021-03-105515590010.711 ppm
2021-03-105515590010.690 ppm
2021-03-105515590010.711 ppm
2021-04-285591850010.660 ppm
2021-04-285591850010.772 ppm
2021-05-185629660010.690 ppm
2021-05-185629660010.731 ppm
2021-06-235692350010.800 ppm
2021-06-235692350010.833 ppm
2021-07-205742180010.670 ppm
2021-07-205742180010.717 ppm
2021-08-095778980010.720 ppm
2021-08-095778980010.763 ppm
2021-09-145843370010.670 ppm
2021-09-145843370010.751 ppm
2021-10-115896950010.600 ppm
2021-10-115896950010.649 ppm
2021-11-165952580010.640 ppm
2021-11-165952580010.746 ppm
2021-12-085979280010.570 ppm
2021-12-085979280010.647 ppm
2022-01-186027510010.530 ppm
2022-01-186027510010.633 ppm
2022-02-086054680010.610 ppm
2022-02-086054680010.662 ppm
2022-03-226107480010.550 ppm
2022-03-226107480010.641 ppm
2022-04-136140830010.540 ppm
2022-04-136140830010.704 ppm
2022-05-036175370010.610 ppm
2022-05-036175370010.760 ppm
2022-06-216267350010.600 ppm
2022-06-216267350010.694 ppm
2022-07-196323240010.600 ppm
2022-07-196323240010.739 ppm
2022-08-086357480010.710 ppm
2022-08-086357480010.835 ppm
2022-09-206440020010.680 ppm
2022-09-206440020010.760 ppm
2022-10-256505200010.570 ppm
2022-10-256505200010.737 ppm
2022-11-286551860010.590 ppm
2022-11-286551860010.608 ppm
2022-12-076566130010.600 ppm
2022-12-076566130010.635 ppm
2023-01-176612260010.710 ppm
2023-01-176612260010.730 ppm
2023-02-076639170010.605 ppm
2023-02-076639170010.610 ppm
2023-03-146687440010.640 ppm
2023-03-146687440010.750 ppm
2023-04-196741640010.610 ppm
2023-04-196741640010.745 ppm
2023-05-226804130010.760 ppm
2023-05-226804130010.851 ppm
2023-06-196857440010.640 ppm
2023-06-196857440010.795 ppm
2023-07-126890180010.630 ppm
2023-07-126890180010.654 ppm
2023-08-236970340010.720 ppm
2023-08-23WB05338-010.790 ppm
2023-08-236970340010.963 ppm
2023-09-257028190010.690 ppm
2023-09-257028190010.731 ppm
2023-10-257082150010.620 ppm
2023-10-257082150010.642 ppm
2023-11-137110900010.700 ppm
2023-11-137110900010.785 ppm
2023-12-127146100010.780 ppm
2023-12-127146100010.887 ppm