Fluoride
Gretna, City of
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 | 0.748 ppm | 15 | 15 | 0.255 ppm - 1.09 ppm |
2015 | 0.883 ppm | 13 | 13 | 0.259 ppm - 1.06 ppm |
2016 | 0.861 ppm | 13 | 13 | 0.241 ppm - 1.04 ppm |
2017 | 0.739 ppm | 13 | 13 | 0.258 ppm - 0.876 ppm |
2018 | 0.766 ppm | 13 | 13 | 0.253 ppm - 1.04 ppm |
2019 | 0.788 ppm | 13 | 13 | 0.378 ppm - 1.05 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 | 279332 | 0.862 ppm |
2014-02-03 | 281396 | 0.307 ppm |
2014-02-03 | 281397 | 0.268 ppm |
2014-02-04 | 284703 | 0.993 ppm |
2014-03-04 | 288736 | 0.897 ppm |
2014-04-07 | 291966 | 0.898 ppm |
2014-05-06 | 297755 | 0.850 ppm |
2014-06-03 | 304082 | 1.000 ppm |
2014-07-08 | 310158 | 0.880 ppm |
2014-07-14 | 308967 | 0.255 ppm |
2014-08-04 | 315550 | 0.268 ppm |
2014-09-02 | 321450 | 1.09 ppm |
2014-10-06 | 326222 | 0.909 ppm |
2014-11-03 | 333617 | 0.831 ppm |
2014-12-02 | 337298 | 0.910 ppm |
2015-01-06 | 341177 | 0.980 ppm |
2015-02-03 | 346770 | 1.06 ppm |
2015-03-02 | 349730 | 1.02 ppm |
2015-04-06 | 354344 | 0.259 ppm |
2015-04-06 | 354690 | 1.04 ppm |
2015-05-05 | 362215 | 0.921 ppm |
2015-06-04 | 366735 | 0.811 ppm |
2015-07-06 | 370745 | 0.668 ppm |
2015-08-05 | 379006 | 0.995 ppm |
2015-09-08 | 384498 | 0.953 ppm |
2015-10-06 | 389361 | 0.951 ppm |
2015-11-02 | 396309 | 0.841 ppm |
2015-12-07 | 400408 | 0.975 ppm |
2016-01-04 | 1.000 ppm | |
2016-02-01 | 0.919 ppm | |
2016-03-07 | 0.898 ppm | |
2016-04-04 | 0.911 ppm | |
2016-05-02 | 1.04 ppm | |
2016-06-07 | 0.952 ppm | |
2016-07-05 | 0.897 ppm | |
2016-07-25 | 0.241 ppm | |
2016-08-01 | 0.836 ppm | |
2016-09-09 | 0.894 ppm | |
2016-10-03 | 0.879 ppm | |
2016-11-07 | 0.869 ppm | |
2016-12-05 | 0.858 ppm | |
2017-01-03 | 0.867 ppm | |
2017-02-06 | 0.831 ppm | |
2017-03-06 | 0.827 ppm | |
2017-04-03 | 0.851 ppm | |
2017-05-02 | 0.876 ppm | |
2017-06-05 | 0.816 ppm | |
2017-07-06 | 0.763 ppm | |
2017-07-31 | 0.258 ppm | |
2017-08-07 | 0.737 ppm | |
2017-09-05 | 0.708 ppm | |
2017-10-02 | 0.664 ppm | |
2017-11-06 | 0.697 ppm | |
2017-12-04 | 0.716 ppm | |
2018-01-02 | 529267 | 0.692 ppm |
2018-02-06 | 534832 | 0.668 ppm |
2018-03-06 | 538465 | 0.758 ppm |
2018-04-02 | 541472 | 0.717 ppm |
2018-04-09 | 543430 | 0.253 ppm |
2018-05-07 | 547735 | 0.788 ppm |
2018-06-11 | 553164 | 1.04 ppm |
2018-07-09 | 557656 | 0.873 ppm |
2018-08-13 | 565403 | 0.808 ppm |
2018-09-10 | 569778 | 0.916 ppm |
2018-10-02 | 575592 | 0.846 ppm |
2018-11-19 | 581134 | 0.745 ppm |
2018-12-10 | 585125 | 0.848 ppm |
2019-01-07 | 588397 | 0.830 ppm |
2019-02-04 | 593810 | 0.822 ppm |
2019-03-18 | 597356 | 0.765 ppm |
2019-04-09 | 601007 | 1.05 ppm |
2019-05-06 | 603031 | 0.378 ppm |
2019-05-13 | 608604 | 0.784 ppm |
2019-06-10 | 612680 | 0.805 ppm |
2019-07-08 | 617854 | 0.848 ppm |
2019-08-12 | 626283 | 0.804 ppm |
2019-09-09 | 630669 | 0.765 ppm |
2019-10-21 | 635840 | 0.794 ppm |
2019-11-11 | 642625 | 0.867 ppm |
2019-12-09 | 648214 | 0.737 ppm |