Fluoride
Sweetwater Authority
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | 0.321 ppm | 12 | 10 | ND - 0.666 ppm |
2015 | 0.338 ppm | 12 | 10 | ND - 0.654 ppm |
2016 | 0.373 ppm | 12 | 10 | ND - 0.651 ppm |
2017 | 0.442 ppm | 11 | 11 | 0.0540 ppm - 0.755 ppm |
2018 | 0.429 ppm | 12 | 11 | ND - 0.659 ppm |
2019 | 0.558 ppm | 6 | 6 | 0.351 ppm - 0.666 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 |
---|---|---|
2014-02-25 | 6100-019-0915 | 0.356 ppm |
2014-02-25 | 6100-018-0855 | 0.312 ppm |
2014-02-25 | 6100-017-0930 | ND |
2014-02-25 | 6100-007-1110 | 0.666 ppm |
2014-02-25 | 6100-005-1115 | 0.291 ppm |
2014-02-25 | 6100-004-0910 | 0.391 ppm |
2014-07-29 | 6100-019-0915 | 0.347 ppm |
2014-07-29 | 6100-018-0935 | 0.321 ppm |
2014-07-29 | 6100-017-0820 | ND |
2014-07-29 | 6100-007-1230 | 0.625 ppm |
2014-07-29 | 6100-005-1240 | 0.185 ppm |
2014-07-29 | 6100-004-0910 | 0.359 ppm |
2015-01-27 | 6100-017-0820 | ND |
2015-01-27 | 6100-018-0950 | 0.312 ppm |
2015-01-27 | 6100-007-1240 | 0.654 ppm |
2015-01-27 | 6100-019-0930 | 0.364 ppm |
2015-01-27 | 6100-005-1250 | 0.311 ppm |
2015-01-27 | 6100-004-0920 | 0.361 ppm |
2015-08-25 | 6100-019-1000 | 0.378 ppm |
2015-08-25 | 6100-018-1005 | 0.348 ppm |
2015-08-25 | 6100-017-0815 | ND |
2015-08-25 | 6100-004-0955 | 0.397 ppm |
2015-08-25 | 6100-007-0750 | 0.591 ppm |
2015-08-25 | 6100-005-0740 | 0.335 ppm |
2016-01-27 | 6100-005-0740 | 0.645 ppm |
2016-01-27 | 6100-019-1005 | 0.365 ppm |
2016-01-27 | 6100-018-1010 | 0.339 ppm |
2016-01-27 | 6100-017-0950 | ND |
2016-01-27 | 6100-007-0735 | 0.651 ppm |
2016-01-27 | 6100-004-1000 | 0.387 ppm |
2016-07-26 | 6100-007-1300 | 0.628 ppm |
2016-07-26 | 6100-017-0840 | ND |
2016-07-26 | 6100-019-1040 | 0.379 ppm |
2016-07-26 | 6100-005-1255 | 0.310 ppm |
2016-07-26 | 6100-004-1035 | 0.414 ppm |
2016-07-26 | 6100-018-1055 | 0.363 ppm |
2017-01-31 | 6100-007-1135 | 0.660 ppm |
2017-01-31 | 6100-019-0950 | 0.629 ppm |
2017-01-31 | 6100-018-0905 | 0.354 ppm |
2017-01-31 | 6100-005-1130 | 0.608 ppm |
2017-01-31 | 6100-004-0955 | 0.388 ppm |
2017-10-03 | 6100-005-1130 | 0.278 ppm |
2017-10-03 | 6100-019-0950 | 0.377 ppm |
2017-10-03 | 6100-007-1135 | 0.755 ppm |
2017-10-03 | 6100-004-0945 | 0.402 ppm |
2017-10-03 | 6100-018-1005 | 0.362 ppm |
2017-10-03 | 6100-017-1130 | 0.0540 ppm |
2018-01-30 | 6100-005-0735 | 0.268 ppm |
2018-01-30 | 6100-007-0730 | 0.596 ppm |
2018-01-30 | 6100-018-1010 | 0.327 ppm |
2018-01-30 | 6100-019-1030 | 0.345 ppm |
2018-01-30 | 6100-004-1025 | 0.365 ppm |
2018-01-30 | 6100-017-1110 | ND |
2018-11-27 | 6100-018-1000 | 0.385 ppm |
2018-11-27 | 6100-019-1007 | 0.560 ppm |
2018-11-27 | 6100-017-0839 | 0.621 ppm |
2018-11-27 | 6100-004-1012 | 0.395 ppm |
2018-11-28 | 6100-005-0740 | 0.629 ppm |
2018-11-28 | 6100-007-0745 | 0.659 ppm |
2019-02-27 | 6100-004-1218 | 0.399 ppm |
2019-02-27 | 6100-017-1015 | 0.666 ppm |
2019-02-27 | 6100-019-1240 | 0.650 ppm |
2019-02-27 | 6100-018-1250 | 0.351 ppm |
2019-02-28 | 6100-005-0800 | 0.630 ppm |
2019-02-28 | 6100-007-0820 | 0.653 ppm |