Fluoride
Tahlequah PWA
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems. Read More.
Fluoride has been promoted as a chemical that reduces dental cavities. Yet it is now well-established that fluoride primarily exerts its protective effects through topical mechanisms, such as sodium fluoride in toothpaste and mouthwash. In contrast, long-term ingestion of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth. 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 fractures, although these effects may occur at lower doses.
Even fluoride levels of 0.7 ppm, the amount of fluoride in drinking water recommended by the U.S. Public Health Service, can result in too much fluoride for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water. The National Toxicology Program is investigating the potential for low doses of fluoride to alter thyroid function and childhood brain development.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 0.794 ppm | 25 | 25 | 0.120 ppm - 1.07 ppm |
| 2015 | 0.706 ppm | 26 | 26 | 0.120 ppm - 0.960 ppm |
| 2016 | 0.610 ppm | 25 | 24 | ND - 0.880 ppm |
| 2017 | 0.593 ppm | 25 | 25 | 0.470 ppm - 0.700 ppm |
| 2018 | 0.618 ppm | 24 | 24 | 0.470 ppm - 0.770 ppm |
| 2019 | 0.673 ppm | 25 | 25 | 0.530 ppm - 0.880 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EPA Maximum Contaminant
Level (MCL) 4 ppm
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-01-07 | 4A08048-01 | 0.730 ppm |
| 2014-01-08 | 4A08050-01 | 0.750 ppm |
| 2014-02-13 | 4B13081-01 | 0.740 ppm |
| 2014-02-25 | 4B26068-01 | 0.770 ppm |
| 2014-03-11 | 4C12097-01 | 0.870 ppm |
| 2014-03-11 | 4C12098-01 | 0.740 ppm |
| 2014-03-18 | 4C19121-01 | 0.750 ppm |
| 2014-04-08 | 4D09087-01 | 1.01 ppm |
| 2014-04-08 | 4D09088-01 | 0.740 ppm |
| 2014-05-06 | 4E07126-01 | 0.870 ppm |
| 2014-05-06 | 4E07127-01 | 0.790 ppm |
| 2014-06-10 | 4F11081-01 | 1.01 ppm |
| 2014-06-11 | 4F11085-01 | 0.740 ppm |
| 2014-07-22 | 4G23088-01 | 1.07 ppm |
| 2014-07-22 | 4G23090-01 | 0.850 ppm |
| 2014-08-05 | 4H06080-01 | 1.04 ppm |
| 2014-08-05 | 4H06151-01 | 0.730 ppm |
| 2014-09-09 | 4I10026-01 | 0.910 ppm |
| 2014-09-09 | 4I10028-01 | 0.910 ppm |
| 2014-10-21 | 4J22055-01 | 0.900 ppm |
| 2014-10-21 | 4J22058-01 | 0.830 ppm |
| 2014-11-18 | 4K19042-01 | 0.120 ppm |
| 2014-11-18 | 4K19043-01 | 0.960 ppm |
| 2014-12-16 | 4L17056-01 | 0.900 ppm |
| 2014-12-16 | 4L17057-01 | 0.120 ppm |
| 2015-01-13 | 5A14025-01 | 0.690 ppm |
| 2015-01-13 | 5A14026-01 | 0.800 ppm |
| 2015-02-17 | 5B25062-01 | 0.940 ppm |
| 2015-02-24 | 5B25061-01 | 0.580 ppm |
| 2015-03-17 | 5C18031-01 | 0.540 ppm |
| 2015-03-17 | 5C18033-01 | 0.790 ppm |
| 2015-04-14 | 5D15045-01 | 0.840 ppm |
| 2015-04-14 | 5D15046-01 | 0.410 ppm |
| 2015-05-13 | 5E13082-01 | 0.530 ppm |
| 2015-05-13 | 5E13084-01 | 0.830 ppm |
| 2015-05-13 | 5E13088-01 | 0.740 ppm |
| 2015-05-13 | 5E13089-01 | 0.830 ppm |
| 2015-06-16 | 5F17097-01 | 0.770 ppm |
| 2015-06-23 | 5F24044-01 | 0.120 ppm |
| 2015-07-21 | 5G22063-01 | 0.830 ppm |
| 2015-07-21 | 5G22065-01 | 0.860 ppm |
| 2015-08-04 | 5H05026-01 | 0.960 ppm |
| 2015-08-04 | 5H05028-01 | 0.810 ppm |
| 2015-09-15 | 5I16059-01 | 0.900 ppm |
| 2015-09-15 | 5I16062-01 | 0.690 ppm |
| 2015-10-27 | 5J28046-01 | 0.710 ppm |
| 2015-10-27 | 5J28047-01 | 0.240 ppm |
| 2015-11-18 | 5K18126-01 | 0.800 ppm |
| 2015-11-18 | 5K18127-01 | 0.830 ppm |
| 2015-12-07 | 5L09062-01 | 0.690 ppm |
| 2015-12-08 | 5L09063-01 | 0.620 ppm |
| 2016-01-19 | 6A20048-01 | 0.560 ppm |
| 2016-01-19 | 6A20050-01 | 0.610 ppm |
| 2016-02-23 | 6B24081-01 | 0.650 ppm |
| 2016-02-23 | 6B24082-01 | 0.180 ppm |
| 2016-03-08 | 6C09086-01 | 0.720 ppm |
| 2016-03-08 | 6C09088-01 | 0.600 ppm |
| 2016-03-08 | 6C09089-01 | 0.710 ppm |
| 2016-04-05 | 6D06023-01 | 0.640 ppm |
| 2016-04-05 | 6D06027-01 | 0.640 ppm |
| 2016-05-10 | 6E11041-01 | ND |
| 2016-05-10 | 6E11042-01 | 0.600 ppm |
| 2016-06-07 | 6F08055-01 | 0.790 ppm |
| 2016-06-07 | 6F08060-01 | 0.680 ppm |
| 2016-07-12 | 6G13038-01 | 0.680 ppm |
| 2016-07-12 | 6G13040-01 | 0.780 ppm |
| 2016-08-16 | 6H17028-01 | 0.880 ppm |
| 2016-08-16 | 6H17029-01 | 0.630 ppm |
| 2016-09-14 | 6I14027-01 | 0.690 ppm |
| 2016-09-20 | 6I21070-01 | 0.640 ppm |
| 2016-10-04 | 6J05054-01 | 0.470 ppm |
| 2016-10-18 | 6J19029-01 | 0.650 ppm |
| 2016-11-08 | 6K09040-01 | 0.530 ppm |
| 2016-11-16 | 6K16115-01 | 0.650 ppm |
| 2016-12-06 | 6L07029-01 | 0.640 ppm |
| 2016-12-20 | 6L21017-01 | 0.630 ppm |
| 2017-01-10 | 7A11015-01 | 0.470 ppm |
| 2017-01-10 | 7A11017-01 | 0.700 ppm |
| 2017-02-07 | 7B08032-01 | 0.610 ppm |
| 2017-02-07 | 7B08039-01 | 0.580 ppm |
| 2017-02-08 | 7B08038-01 | 0.630 ppm |
| 2017-03-08 | 7C08030-01 | 0.570 ppm |
| 2017-03-08 | 7C08031-01 | 0.690 ppm |
| 2017-04-07 | 7D12021-01 | 0.610 ppm |
| 2017-04-10 | 7D12022-01 | 0.670 ppm |
| 2017-05-02 | 7E03026-01 | 0.570 ppm |
| 2017-05-02 | 7E03027-01 | 0.660 ppm |
| 2017-06-05 | 7F07020-01 | 0.620 ppm |
| 2017-06-06 | 7F07022-01 | 0.610 ppm |
| 2017-07-07 | 7G12017-01 | 0.500 ppm |
| 2017-07-07 | 7G12019-01 | 0.560 ppm |
| 2017-08-02 | 7H02041-01 | 0.510 ppm |
| 2017-08-15 | 7H16145-01 | 0.600 ppm |
| 2017-09-07 | 7I13022-01 | 0.560 ppm |
| 2017-09-08 | 7I13023-01 | 0.590 ppm |
| 2017-10-24 | 7J25022-01 | 0.550 ppm |
| 2017-10-24 | 7J25114-01 | 0.580 ppm |
| 2017-11-07 | 7K08024-01 | 0.560 ppm |
| 2017-11-07 | 7K08025-01 | 0.650 ppm |
| 2017-12-05 | 7L06052-01 | 0.630 ppm |
| 2017-12-06 | 7L06050-01 | 0.540 ppm |
| 2018-01-04 | 8A10024-01 | 0.560 ppm |
| 2018-01-04 | 8A10026-01 | 0.570 ppm |
| 2018-02-05 | AB07208-01 | 0.610 ppm |
| 2018-02-06 | AB07215-01 | 0.600 ppm |
| 2018-03-06 | AC07030-01 | 0.570 ppm |
| 2018-03-13 | AC14045-01 | 0.550 ppm |
| 2018-04-03 | AD04045-01 | 0.470 ppm |
| 2018-04-09 | AD11045-01 | 0.660 ppm |
| 2018-05-04 | AE09037-01 | 0.550 ppm |
| 2018-05-10 | AE16043-01 | 0.640 ppm |
| 2018-06-07 | AF13088-01 | 0.700 ppm |
| 2018-06-08 | AF13185-01 | 0.720 ppm |
| 2018-07-05 | AG11165-01 | 0.630 ppm |
| 2018-07-06 | AG11164-01 | 0.590 ppm |
| 2018-08-08 | AH08060-01 | 0.570 ppm |
| 2018-08-09 | AH15028-01 | 0.590 ppm |
| 2018-09-10 | AI12036-01 | 0.580 ppm |
| 2018-09-11 | AI12035-01 | 0.540 ppm |
| 2018-10-03 | AJ03048-01 | 0.620 ppm |
| 2018-10-16 | AJ17031-01 | 0.670 ppm |
| 2018-11-02 | AK07048-01 | 0.770 ppm |
| 2018-11-14 | AK14026-01 | 0.690 ppm |
| 2018-12-04 | AL05062-01 | 0.640 ppm |
| 2018-12-07 | AL12025-01 | 0.730 ppm |
| 2019-01-07 | BA09021-01 | 0.540 ppm |
| 2019-01-15 | BA16035-01 | 0.590 ppm |
| 2019-01-15 | BA16035-01 | 0.590 ppm |
| 2019-02-04 | BB06031-01 | 0.690 ppm |
| 2019-02-26 | BB27015-01 | 0.550 ppm |
| 2019-03-08 | BC13011-01 | 0.780 ppm |
| 2019-03-11 | BC13012-01 | 0.570 ppm |
| 2019-03-26 | BC27022-01 | 0.530 ppm |
| 2019-03-26 | BC27031-01 | 0.810 ppm |
| 2019-04-04 | BD10011-01 | 0.790 ppm |
| 2019-04-09 | BD10012-01 | 0.620 ppm |
| 2019-05-14 | BE15086-01 | 0.560 ppm |
| 2019-05-21 | BE22030-01 | 0.730 ppm |
| 2019-06-11 | BF12027-01 | 0.730 ppm |
| 2019-06-11 | BF12028-01 | 0.660 ppm |
| 2019-07-05 | BG10050-01 | 0.830 ppm |
| 2019-07-09 | BG10049-01 | 0.720 ppm |
| 2019-08-15 | BH21149-01 | 0.880 ppm |
| 2019-09-20 | BI25032-01 | 0.720 ppm |
| 2019-10-04 | BJ09092-01 | 0.630 ppm |
| 2019-10-07 | BJ09091-01 | 0.770 ppm |
| 2019-11-04 | BK06074-01 | 0.840 ppm |
| 2019-11-05 | BK06066-01 | 0.590 ppm |
| 2019-12-02 | BL04041-01 | 0.550 ppm |
| 2019-12-11 | BL18041-01 | 0.560 ppm |