Know Your Environment. Protect Your Health.

Fluoride

Colby 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.

 

148

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.672 ppm24240.520 ppm - 0.770 ppm
20190.668 ppm24240.547 ppm - 0.750 ppm
20200.681 ppm22220.597 ppm - 0.740 ppm
20210.678 ppm28280.624 ppm - 0.730 ppm
20220.691 ppm24240.650 ppm - 0.723 ppm
20230.695 ppm26260.650 ppm - 0.751 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
2018-01-083619690010.660 ppm
2018-01-083619690010.665 ppm
2018-02-073661170010.698 ppm
2018-02-073661170010.740 ppm
2018-03-073703110010.720 ppm
2018-03-073703110010.739 ppm
2018-04-063753930010.618 ppm
2018-04-063753930010.680 ppm
2018-05-103821470010.694 ppm
2018-05-103821470010.710 ppm
2018-06-083879180010.634 ppm
2018-06-083879180010.690 ppm
2018-07-273978170010.611 ppm
2018-07-273978170010.670 ppm
2018-08-154017160010.567 ppm
2018-08-154017160010.750 ppm
2018-09-114077700010.520 ppm
2018-09-114077700010.760 ppm
2018-10-024125430010.643 ppm
2018-10-024125430010.770 ppm
2018-11-094198710010.560 ppm
2018-11-094198710010.710 ppm
2018-12-054239870010.593 ppm
2018-12-054239870010.730 ppm
2019-01-024261040010.658 ppm
2019-01-024261040010.700 ppm
2019-02-084325280010.706 ppm
2019-02-084325280010.730 ppm
2019-03-054344210010.715 ppm
2019-03-054344210010.730 ppm
2019-04-024387920010.668 ppm
2019-04-024387920010.710 ppm
2019-05-064452140010.667 ppm
2019-05-064452140010.750 ppm
2019-06-104518900010.700 ppm
2019-06-104518900010.741 ppm
2019-07-164584280010.592 ppm
2019-07-164584280010.650 ppm
2019-08-054622010010.654 ppm
2019-08-054622010010.680 ppm
2019-09-064680490010.572 ppm
2019-09-064680490010.660 ppm
2019-10-014743100010.615 ppm
2019-10-014743100010.660 ppm
2019-11-064805380010.578 ppm
2019-11-064805380010.700 ppm
2019-12-134860230010.547 ppm
2019-12-134860230010.660 ppm
2020-01-074884760010.597 ppm
2020-01-074884760010.690 ppm
2020-04-034997800010.680 ppm
2020-04-034997800010.691 ppm
2020-04-2111842590.640 ppm
2020-04-2111842580.660 ppm
2020-05-055035030010.665 ppm
2020-05-055035030010.740 ppm
2020-06-015078030010.684 ppm
2020-06-015078030010.710 ppm
2020-07-085139240010.660 ppm
2020-07-085139240010.734 ppm
2020-08-045184710010.632 ppm
2020-08-045184710010.690 ppm
2020-09-025236510010.696 ppm
2020-09-025236510010.740 ppm
2020-10-055303170010.692 ppm
2020-10-055303170010.700 ppm
2020-11-035348170010.597 ppm
2020-11-035348170010.710 ppm
2020-12-015386120010.635 ppm
2020-12-015386120010.730 ppm
2021-01-055426660010.664 ppm
2021-01-055426660010.710 ppm
2021-02-015462580010.631 ppm
2021-02-015462580010.710 ppm
2021-02-015462580010.631 ppm
2021-02-015462580010.710 ppm
2021-03-025498820010.624 ppm
2021-03-025498820010.670 ppm
2021-03-025498820010.624 ppm
2021-03-025498820010.670 ppm
2021-04-065552750010.661 ppm
2021-04-065552750010.710 ppm
2021-05-055605110010.669 ppm
2021-05-055605110010.700 ppm
2021-06-015649220010.660 ppm
2021-06-015649220010.700 ppm
2021-07-095713550010.650 ppm
2021-07-095713550010.708 ppm
2021-08-045765330010.655 ppm
2021-08-045765330010.690 ppm
2021-09-135848790010.674 ppm
2021-09-135848790010.710 ppm
2021-10-065896980010.651 ppm
2021-10-065896980010.700 ppm
2021-11-015931950010.681 ppm
2021-11-015931950010.730 ppm
2021-12-075979300010.669 ppm
2021-12-075979300010.710 ppm
2022-01-046010030010.680 ppm
2022-01-046010030010.682 ppm
2022-02-036045510010.664 ppm
2022-02-036045510010.700 ppm
2022-03-036081160010.680 ppm
2022-03-036081160010.720 ppm
2022-04-056127330010.656 ppm
2022-04-056127330010.700 ppm
2022-05-036175460010.685 ppm
2022-05-036175460010.700 ppm
2022-06-016227190010.650 ppm
2022-06-016227190010.653 ppm
2022-07-116304010010.710 ppm
2022-07-116304010010.710 ppm
2022-08-026350510010.720 ppm
2022-08-026350510010.723 ppm
2022-09-136425400010.704 ppm
2022-09-136425400010.710 ppm
2022-10-056472920010.689 ppm
2022-10-056472920010.690 ppm
2022-11-016517600010.700 ppm
2022-11-016517600010.712 ppm
2022-12-056561890010.658 ppm
2022-12-056561890010.680 ppm
2023-01-096600420010.710 ppm
2023-01-096600420010.717 ppm
2023-02-066644310010.720 ppm
2023-02-066644310010.751 ppm
2023-03-066677830010.663 ppm
2023-03-066677830010.740 ppm
2023-04-076727670010.678 ppm
2023-04-076727670010.700 ppm
2023-05-016766780010.672 ppm
2023-05-016766780010.720 ppm
2023-06-066828940010.656 ppm
2023-06-066828940010.720 ppm
2023-07-116899810010.660 ppm
2023-07-116899810010.691 ppm
2023-07-25CB08518-010.650 ppm
2023-07-25CB08518-050.690 ppm
2023-08-076940790010.670 ppm
2023-08-076940790010.722 ppm
2023-09-066991480010.668 ppm
2023-09-066991480010.740 ppm
2023-10-067048970010.650 ppm
2023-10-067048970010.669 ppm
2023-11-037099070010.720 ppm
2023-11-037099070010.730 ppm
2023-12-047139970010.684 ppm
2023-12-047139970010.690 ppm