Fluoride
OSU Water Plant
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 |
|---|---|---|---|---|
| 2014 | 0.458 ppm | 11 | 8 | ND - 0.830 ppm |
| 2015 | 0.199 ppm | 12 | 5 | ND - 0.580 ppm |
| 2016 | 0.724 ppm | 13 | 13 | 0.160 ppm - 1.28 ppm |
| 2017 | 0.796 ppm | 12 | 12 | 0.180 ppm - 1.10 ppm |
| 2018 | 0.833 ppm | 11 | 11 | 0.600 ppm - 1.01 ppm |
| 2019 | 0.834 ppm | 13 | 13 | 0.520 ppm - 1.07 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 |
|---|---|---|
| 2014-01-17 | 4A17014-01 | 0.520 ppm |
| 2014-02-19 | 4B20010-01 | 0.570 ppm |
| 2014-03-25 | 4C26043-01 | 0.730 ppm |
| 2014-04-09 | 4D10067-01 | 0.830 ppm |
| 2014-06-09 | 4F11152-01 | 0.700 ppm |
| 2014-07-22 | 4G23124-01 | 0.570 ppm |
| 2014-08-12 | 4H13114-01 | 0.540 ppm |
| 2014-09-18 | 1335624 | ND |
| 2014-10-30 | 4J30041-01 | 0.580 ppm |
| 2014-11-05 | 1348357 | ND |
| 2014-12-04 | 1355303 | ND |
| 2015-01-15 | 1365151 | 0.548 ppm |
| 2015-02-05 | 1370646 | 0.501 ppm |
| 2015-03-24 | 5C25011-01 | 0.580 ppm |
| 2015-04-15 | 5D22064-01 | 0.340 ppm |
| 2015-06-02 | 5F02022-01 | 0.420 ppm |
| 2015-06-19 | 1404497 | ND |
| 2015-07-22 | 1413095 | ND |
| 2015-08-13 | 1420044 | ND |
| 2015-09-17 | 1428508 | ND |
| 2015-10-07 | 1433903 | ND |
| 2015-11-11 | 1444037 | ND |
| 2015-12-09 | 1450700 | ND |
| 2016-01-13 | 1458956 | 0.511 ppm |
| 2016-02-09 | 6B09081-01 | 0.280 ppm |
| 2016-03-10 | 6C10031-01 | 0.290 ppm |
| 2016-04-04 | 6D04085-01 | 0.630 ppm |
| 2016-05-04 | 6E04020-01 | 0.860 ppm |
| 2016-06-07 | 6F08007-01 | 0.800 ppm |
| 2016-07-06 | 6G06044-01 | 0.180 ppm |
| 2016-08-09 | 6H09029-01 | 0.160 ppm |
| 2016-09-13 | 6I13027-01 | 1.03 ppm |
| 2016-10-07 | 6J07005-01 | 1.18 ppm |
| 2016-11-08 | 6K08028-01 | 1.07 ppm |
| 2016-12-06 | 6L06110-01 | 1.28 ppm |
| 2016-12-06 | 6L06113-01 | 1.14 ppm |
| 2017-01-05 | 7A05078-01 | 0.750 ppm |
| 2017-02-07 | 7B07037-01 | 0.640 ppm |
| 2017-03-07 | 7C07130-01 | 1.04 ppm |
| 2017-04-04 | 7D04093-01 | 0.980 ppm |
| 2017-05-02 | 7E02077-01 | 0.930 ppm |
| 2017-06-06 | 7F06131-01 | 0.800 ppm |
| 2017-07-10 | 7G10075-01 | 1.10 ppm |
| 2017-08-01 | 7H01036-01 | 0.180 ppm |
| 2017-09-07 | 7I07018-01 | 0.790 ppm |
| 2017-10-03 | 7J03041-01 | 0.840 ppm |
| 2017-11-02 | 7K02085-01 | 0.760 ppm |
| 2017-12-01 | 7L01007-01 | 0.740 ppm |
| 2018-02-01 | AB01061-01 | 0.840 ppm |
| 2018-03-01 | AC01050-01 | 0.870 ppm |
| 2018-04-03 | AD03088-01 | 0.830 ppm |
| 2018-05-02 | AE02170-01 | 0.760 ppm |
| 2018-06-01 | AF01017-01 | 0.860 ppm |
| 2018-07-03 | AG03063-01 | 0.760 ppm |
| 2018-08-06 | AH06053-01 | 1.01 ppm |
| 2018-09-06 | AI06092-01 | 0.980 ppm |
| 2018-10-04 | AJ04082-01 | 0.860 ppm |
| 2018-11-02 | AK02004-01 | 0.790 ppm |
| 2018-12-10 | AL10035-01 | 0.600 ppm |
| 2019-01-04 | BA04030-01 | 0.650 ppm |
| 2019-01-07 | BA07046-01 | 0.670 ppm |
| 2019-02-06 | BB06045-01 | 0.970 ppm |
| 2019-03-01 | BC01009-01 | 0.710 ppm |
| 2019-04-08 | BD08046-01 | 0.930 ppm |
| 2019-05-02 | BE02081-01 | 1.01 ppm |
| 2019-06-03 | BF03083-01 | 0.860 ppm |
| 2019-07-23 | BG23055-01 | 0.580 ppm |
| 2019-08-02 | BH02029-01 | 0.910 ppm |
| 2019-09-10 | BI10017-01 | 1.07 ppm |
| 2019-10-02 | BJ02116-01 | 0.920 ppm |
| 2019-11-06 | BK06104-01 | 1.04 ppm |
| 2019-12-04 | BL04047-01 | 0.520 ppm |