Know Your Environment. Protect Your Health.

Fluoride

Wisconsin Dells 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.

 

156

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.645 ppm24240.475 ppm - 0.756 ppm
20190.672 ppm24240.543 ppm - 0.826 ppm
20200.587 ppm2625ND - 0.768 ppm
20210.582 ppm28280.466 ppm - 0.706 ppm
20220.607 ppm24240.454 ppm - 0.671 ppm
20230.551 ppm3028ND - 0.670 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
2018-01-293646690010.621 ppm
2018-01-293646690010.650 ppm
2018-02-073660790010.680 ppm
2018-02-073660790010.756 ppm
2018-03-193719160010.658 ppm
2018-03-193719160010.700 ppm
2018-04-243781550010.475 ppm
2018-04-243781550010.680 ppm
2018-05-173831670010.589 ppm
2018-05-173831670010.740 ppm
2018-06-043861640010.641 ppm
2018-06-043861640010.690 ppm
2018-07-203958630010.615 ppm
2018-07-203958630010.670 ppm
2018-08-144012350010.538 ppm
2018-08-144012350010.630 ppm
2018-09-214095960010.491 ppm
2018-09-214095960010.690 ppm
2018-10-034125030010.613 ppm
2018-10-034125030010.670 ppm
2018-11-024175080010.680 ppm
2018-11-024175080010.748 ppm
2018-12-184251590010.569 ppm
2018-12-184251590010.690 ppm
2019-01-164282500010.543 ppm
2019-01-164282500010.670 ppm
2019-02-224326720010.556 ppm
2019-02-224326720010.710 ppm
2019-03-154355680010.555 ppm
2019-03-154355680010.690 ppm
2019-04-234421230010.658 ppm
2019-04-234421230010.720 ppm
2019-05-224478400010.642 ppm
2019-05-224478400010.690 ppm
2019-06-134517780010.640 ppm
2019-06-134517780010.826 ppm
2019-07-124572380010.690 ppm
2019-07-124572380010.691 ppm
2019-08-194647760010.690 ppm
2019-08-194647760010.699 ppm
2019-09-054679190010.657 ppm
2019-09-054679190010.680 ppm
2019-10-254782470010.680 ppm
2019-10-254782470010.690 ppm
2019-11-264834730010.660 ppm
2019-11-264834730010.677 ppm
2019-12-134860170010.691 ppm
2019-12-134860170010.730 ppm
2020-01-204903200010.454 ppm
2020-01-204903200010.650 ppm
2020-04-235019730010.640 ppm
2020-04-235019730010.659 ppm
2020-05-085038440010.660 ppm
2020-05-085038440010.695 ppm
2020-06-105092850010.620 ppm
2020-06-105092850010.686 ppm
2020-07-235164520010.639 ppm
2020-07-235164520010.640 ppm
2020-08-185208890010.597 ppm
2020-08-185208890010.660 ppm
2020-09-104718570.560 ppm
2020-09-11472173ND
2020-09-114721810.300 ppm
2020-09-114721650.590 ppm
2020-09-114721700.610 ppm
2020-09-114721850.650 ppm
2020-09-245277580010.620 ppm
2020-09-245277580010.768 ppm
2020-10-275334710010.598 ppm
2020-10-275334710010.640 ppm
2020-11-235373700010.544 ppm
2020-11-235373700010.640 ppm
2020-12-175409880010.519 ppm
2020-12-175409880010.620 ppm
2021-01-285454280010.489 ppm
2021-01-285454280010.570 ppm
2021-02-235488720010.466 ppm
2021-02-235488720010.560 ppm
2021-02-235488720010.466 ppm
2021-02-235488720010.560 ppm
2021-03-175523870010.500 ppm
2021-03-175523870010.570 ppm
2021-03-175523870010.500 ppm
2021-03-175523870010.570 ppm
2021-04-065552260010.582 ppm
2021-04-065552260010.650 ppm
2021-05-115614160010.582 ppm
2021-05-115614160010.620 ppm
2021-06-215682780010.528 ppm
2021-06-215682780010.600 ppm
2021-07-085711830010.610 ppm
2021-07-085711830010.612 ppm
2021-08-195794840010.610 ppm
2021-08-195794840010.652 ppm
2021-09-175843510010.623 ppm
2021-09-175843510010.630 ppm
2021-10-195906490010.640 ppm
2021-10-195906490010.706 ppm
2021-11-295961320010.573 ppm
2021-11-295961320010.680 ppm
2021-12-075977770010.538 ppm
2021-12-075977770010.620 ppm
2022-01-066010530010.508 ppm
2022-01-066010530010.660 ppm
2022-02-256071810010.623 ppm
2022-02-256071810010.660 ppm
2022-03-086087660010.487 ppm
2022-03-086087660010.630 ppm
2022-04-126139180010.567 ppm
2022-04-126139180010.660 ppm
2022-05-166207010010.581 ppm
2022-05-166207010010.630 ppm
2022-06-166258520010.454 ppm
2022-06-166258520010.620 ppm
2022-07-166323150010.490 ppm
2022-07-166323150010.620 ppm
2022-08-176377890010.630 ppm
2022-08-176377890010.671 ppm
2022-09-086414780010.640 ppm
2022-09-086414780010.649 ppm
2022-10-126485850010.545 ppm
2022-10-126485850010.640 ppm
2022-11-026516410010.660 ppm
2022-11-026516410010.664 ppm
2022-12-066569850010.619 ppm
2022-12-066569850010.660 ppm
2023-01-246622820010.579 ppm
2023-01-246622820010.630 ppm
2023-02-166651190010.575 ppm
2023-02-166651190010.650 ppm
2023-03-286703190010.483 ppm
2023-03-286703190010.660 ppm
2023-04-206746310010.453 ppm
2023-04-206746310010.630 ppm
2023-04-261317740ND
2023-04-261317742ND
2023-05-2313278620.390 ppm
2023-05-236805760010.493 ppm
2023-05-236805760010.660 ppm
2023-06-156841530010.539 ppm
2023-06-156841530010.660 ppm
2023-06-2013373910.610 ppm
2023-07-1813492490.430 ppm
2023-07-1813492530.570 ppm
2023-07-246908240010.594 ppm
2023-07-246908240010.650 ppm
2023-08-286973630010.523 ppm
2023-08-286973630010.620 ppm
2023-09-267032100010.645 ppm
2023-09-267032100010.650 ppm
2023-10-187073250010.629 ppm
2023-10-187073250010.650 ppm
2023-11-147114980010.631 ppm
2023-11-147114980010.670 ppm
2023-12-077138890010.616 ppm
2023-12-077138890010.640 ppm