Fluoride
Selbyville Water Department
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 | 0.526 ppm | 12 | 9 | ND - 1.54 ppm |
2015 | 0.508 ppm | 12 | 10 | ND - 1.05 ppm |
2016 | 0.629 ppm | 8 | 6 | ND - 1.16 ppm |
2017 | 0.850 ppm | 9 | 7 | ND - 1.40 ppm |
2018 | 0.711 ppm | 13 | 10 | ND - 1.34 ppm |
2019 | 0.726 ppm | 13 | 13 | 0.535 ppm - 0.893 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 |
---|---|---|
2014-01-30 | S38150 | ND |
2014-02-20 | S38156 | ND |
2014-03-20 | S38162 | 0.970 ppm |
2014-04-29 | S38168 | ND |
2014-06-25 | S547078 | 0.290 ppm |
2014-07-29 | S547084 | 0.340 ppm |
2014-08-26 | S547090 | 0.670 ppm |
2014-09-24 | S547101 | 0.920 ppm |
2014-10-28 | S547102 | 0.550 ppm |
2014-11-12 | S589893 | 0.630 ppm |
2014-11-24 | S547108 | 1.54 ppm |
2014-12-18 | S547114 | 0.400 ppm |
2015-01-13 | S548223 | 0.670 ppm |
2015-02-24 | S548224 | 0.250 ppm |
2015-03-25 | S6548232 | ND |
2015-04-28 | S553218 | 0.640 ppm |
2015-05-27 | S553224 | 0.670 ppm |
2015-06-24 | S553231 | 0.600 ppm |
2015-07-28 | S548237 | 0.610 ppm |
2015-08-27 | S548243 | 0.580 ppm |
2015-09-29 | S548244 | 0.840 ppm |
2015-10-27 | S548249 | ND |
2015-11-30 | S548250 | 1.05 ppm |
2015-12-28 | S548253 | 0.190 ppm |
2016-01-12 | S676192 | 0.960 ppm |
2016-01-27 | S548256 | 0.860 ppm |
2016-03-07 | S548262 | ND |
2016-03-29 | S548263 | 0.460 ppm |
2016-04-27 | S548268 | 0.560 ppm |
2016-05-25 | S548269 | 1.03 ppm |
2016-06-22 | S548272 | 1.16 ppm |
2016-07-28 | S548275 | ND |
2017-01-16 | S782200 | 0.820 ppm |
2017-02-06 | S693947 | ND |
2017-06-27 | S548307 | 1.40 ppm |
2017-07-18 | S548310 | 1.18 ppm |
2017-08-15 | S548315 | 1.29 ppm |
2017-09-20 | S548318 | ND |
2017-10-24 | S548319 | 1.16 ppm |
2017-11-29 | S553212 | 0.710 ppm |
2017-12-27 | S553204 | 1.09 ppm |
2018-01-31 | S553208 | 0.220 ppm |
2018-02-27 | S553213 | 1.34 ppm |
2018-03-27 | S548323 | 1.10 ppm |
2018-04-26 | S548328 | 1.04 ppm |
2018-05-30 | S548331 | 1.08 ppm |
2018-06-28 | S548336 | ND |
2018-07-31 | S548342 | ND |
2018-08-29 | S548345 | ND |
2018-09-26 | S548346 | 1.16 ppm |
2018-10-31 | S548353 | 0.941 ppm |
2018-11-29 | S548356 | 0.760 ppm |
2018-12-13 | S792261 | 0.822 ppm |
2018-12-27 | S548357 | 0.781 ppm |
2019-01-29 | S548360 | 0.781 ppm |
2019-02-26 | S548363 | 0.700 ppm |
2019-03-27 | S548349 | 0.729 ppm |
2019-04-30 | S548352 | 0.794 ppm |
2019-05-09 | S698773 | 0.893 ppm |
2019-06-26 | S698778 | 0.828 ppm |
2019-07-31 | S698785 | 0.721 ppm |
2019-08-22 | S698788 | 0.794 ppm |
2019-09-26 | S698791 | 0.719 ppm |
2019-10-29 | S698794 | 0.724 ppm |
2019-11-26 | S698797 | 0.582 ppm |
2019-11-27 | S925292 | 0.535 ppm |
2019-12-12 | S698800 | 0.644 ppm |