Fluoride
Granger - Hunter Improvement District
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 | 0.693 ppm | 76 | 76 | 0.373 ppm - 0.992 ppm |
2015 | 0.721 ppm | 64 | 64 | 0.488 ppm - 1.75 ppm |
2016 | 0.678 ppm | 17 | 17 | 0.500 ppm - 0.882 ppm |
2017 | 0.586 ppm | 21 | 21 | 0.215 ppm - 0.719 ppm |
2018 | N/A | 0 | 0 | N/A |
2019 | N/A | 0 | 0 | N/A |
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 | Result |
---|---|
2014-03-04 | 0.755 ppm |
2014-03-04 | 0.723 ppm |
2014-03-04 | 0.874 ppm |
2014-03-04 | 0.872 ppm |
2014-03-04 | 0.757 ppm |
2014-03-19 | 0.829 ppm |
2014-03-19 | 0.830 ppm |
2014-03-19 | 0.753 ppm |
2014-03-19 | 0.764 ppm |
2014-03-19 | 0.663 ppm |
2014-05-07 | 0.551 ppm |
2014-05-07 | 0.769 ppm |
2014-05-07 | 0.772 ppm |
2014-05-07 | 0.761 ppm |
2014-05-07 | 0.465 ppm |
2014-05-22 | 0.754 ppm |
2014-05-22 | 0.757 ppm |
2014-05-22 | 0.524 ppm |
2014-05-22 | 0.475 ppm |
2014-05-22 | 0.769 ppm |
2014-05-23 | 0.400 ppm |
2014-06-04 | 0.992 ppm |
2014-06-04 | 0.754 ppm |
2014-06-04 | 0.720 ppm |
2014-06-04 | 0.565 ppm |
2014-06-04 | 0.730 ppm |
2014-06-18 | 0.782 ppm |
2014-06-18 | 0.724 ppm |
2014-06-18 | 0.894 ppm |
2014-06-18 | 0.769 ppm |
2014-06-18 | 0.524 ppm |
2014-07-09 | 0.400 ppm |
2014-07-09 | 0.500 ppm |
2014-07-09 | 0.400 ppm |
2014-07-09 | 0.500 ppm |
2014-07-09 | 0.500 ppm |
2014-09-03 | 0.477 ppm |
2014-09-03 | 0.699 ppm |
2014-09-03 | 0.373 ppm |
2014-09-03 | 0.620 ppm |
2014-09-03 | 0.693 ppm |
2014-09-25 | 0.870 ppm |
2014-09-25 | 0.705 ppm |
2014-09-25 | 0.706 ppm |
2014-09-25 | 0.659 ppm |
2014-09-25 | 0.735 ppm |
2014-10-08 | 0.733 ppm |
2014-10-08 | 0.711 ppm |
2014-10-08 | 0.418 ppm |
2014-10-08 | 0.711 ppm |
2014-10-08 | 0.686 ppm |
2014-10-28 | 0.770 ppm |
2014-10-28 | 0.719 ppm |
2014-10-28 | 0.710 ppm |
2014-10-28 | 0.718 ppm |
2014-10-28 | 0.736 ppm |
2014-11-05 | 0.752 ppm |
2014-11-05 | 0.745 ppm |
2014-11-05 | 0.754 ppm |
2014-11-05 | 0.749 ppm |
2014-11-05 | 0.734 ppm |
2014-11-20 | 0.688 ppm |
2014-11-20 | 0.742 ppm |
2014-11-20 | 0.733 ppm |
2014-11-20 | 0.729 ppm |
2014-11-20 | 0.740 ppm |
2014-12-04 | 0.694 ppm |
2014-12-04 | 0.731 ppm |
2014-12-04 | 0.711 ppm |
2014-12-04 | 0.762 ppm |
2014-12-04 | 0.742 ppm |
2014-12-10 | 0.677 ppm |
2014-12-10 | 0.707 ppm |
2014-12-10 | 0.759 ppm |
2014-12-10 | 0.741 ppm |
2014-12-10 | 0.742 ppm |
2015-01-07 | 0.800 ppm |
2015-01-07 | 0.733 ppm |
2015-01-07 | 0.737 ppm |
2015-01-07 | 0.704 ppm |
2015-01-07 | 0.694 ppm |
2015-01-17 | 0.696 ppm |
2015-01-21 | 0.677 ppm |
2015-01-21 | 0.488 ppm |
2015-01-21 | 0.659 ppm |
2015-01-21 | 0.742 ppm |
2015-01-21 | 0.716 ppm |
2015-01-21 | 0.741 ppm |
2015-02-04 | 0.747 ppm |
2015-02-04 | 0.857 ppm |
2015-02-04 | 0.740 ppm |
2015-02-04 | 0.733 ppm |
2015-02-04 | 0.733 ppm |
2015-02-04 | 0.731 ppm |
2015-02-18 | 0.798 ppm |
2015-02-18 | 0.761 ppm |
2015-02-18 | 0.747 ppm |
2015-02-18 | 0.512 ppm |
2015-02-18 | 0.738 ppm |
2015-02-18 | 1.75 ppm |
2015-07-08 | 0.710 ppm |
2015-07-08 | 0.697 ppm |
2015-07-08 | 0.885 ppm |
2015-07-08 | 0.684 ppm |
2015-07-08 | 0.705 ppm |
2015-07-09 | 0.719 ppm |
2015-07-22 | 0.688 ppm |
2015-07-22 | 0.669 ppm |
2015-07-22 | 0.492 ppm |
2015-07-22 | 0.708 ppm |
2015-07-28 | 0.698 ppm |
2015-07-28 | 0.705 ppm |
2015-07-30 | 0.500 ppm |
2015-07-30 | 0.500 ppm |
2015-07-30 | 0.500 ppm |
2015-07-30 | 0.500 ppm |
2015-07-30 | 0.700 ppm |
2015-09-09 | 0.689 ppm |
2015-09-09 | 0.763 ppm |
2015-09-09 | 0.741 ppm |
2015-09-09 | 0.735 ppm |
2015-09-09 | 0.753 ppm |
2015-09-09 | 0.719 ppm |
2015-09-24 | 0.724 ppm |
2015-09-24 | 0.766 ppm |
2015-09-24 | 0.752 ppm |
2015-09-24 | 0.744 ppm |
2015-09-24 | 0.744 ppm |
2015-09-24 | 0.751 ppm |
2015-11-05 | 0.743 ppm |
2015-11-05 | 0.749 ppm |
2015-11-05 | 0.730 ppm |
2015-11-05 | 0.729 ppm |
2015-11-05 | 0.750 ppm |
2015-11-18 | 0.741 ppm |
2015-11-18 | 0.729 ppm |
2015-11-18 | 0.681 ppm |
2015-11-18 | 0.741 ppm |
2015-11-18 | 0.678 ppm |
2015-11-18 | 0.700 ppm |
2016-07-19 | 0.700 ppm |
2016-07-19 | 0.500 ppm |
2016-07-19 | 0.500 ppm |
2016-07-19 | 0.500 ppm |
2016-07-19 | 0.500 ppm |
2016-11-09 | 0.732 ppm |
2016-11-09 | 0.796 ppm |
2016-11-09 | 0.820 ppm |
2016-11-09 | 0.729 ppm |
2016-11-09 | 0.624 ppm |
2016-11-09 | 0.651 ppm |
2016-11-17 | 0.726 ppm |
2016-11-17 | 0.721 ppm |
2016-11-17 | 0.882 ppm |
2016-11-17 | 0.714 ppm |
2016-11-17 | 0.702 ppm |
2016-11-17 | 0.724 ppm |
2017-01-11 | 0.400 ppm |
2017-06-21 | 0.671 ppm |
2017-06-21 | 0.456 ppm |
2017-06-21 | 0.449 ppm |
2017-06-21 | 0.520 ppm |
2017-06-21 | 0.355 ppm |
2017-06-28 | 0.215 ppm |
2017-08-07 | 0.661 ppm |
2017-08-07 | 0.627 ppm |
2017-08-07 | 0.684 ppm |
2017-08-07 | 0.692 ppm |
2017-08-07 | 0.693 ppm |
2017-08-10 | 0.625 ppm |
2017-08-10 | 0.555 ppm |
2017-08-16 | 0.647 ppm |
2017-08-16 | 0.637 ppm |
2017-08-16 | 0.719 ppm |
2017-08-16 | 0.683 ppm |
2017-08-16 | 0.634 ppm |
2017-08-16 | 0.715 ppm |
2017-08-16 | 0.669 ppm |