Fluoride
City of Bozeman
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 |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 0.790 ppm | 25 | 24 | ND - 1.08 ppm |
| 2015 | 0.685 ppm | 24 | 24 | 0.160 ppm - 1.06 ppm |
| 2016 | 0.645 ppm | 24 | 24 | 0.427 ppm - 0.862 ppm |
| 2017 | 0.599 ppm | 25 | 24 | ND - 0.895 ppm |
| 2018 | 0.661 ppm | 24 | 24 | 0.558 ppm - 0.758 ppm |
| 2019 | 0.652 ppm | 24 | 24 | 0.547 ppm - 0.800 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 |
|---|---|---|
| 2014-01-06 | C1401-0022 | 1.08 ppm |
| 2014-01-06 | C1401-0023 | 0.990 ppm |
| 2014-02-03 | C1401-0708 | 0.940 ppm |
| 2014-02-03 | C1401-0709 | 0.940 ppm |
| 2014-03-03 | C1403-1032 | 0.920 ppm |
| 2014-03-03 | C1403-1033 | 0.980 ppm |
| 2014-04-01 | C1404-1118 | 0.480 ppm |
| 2014-04-01 | C1404-1119 | 0.980 ppm |
| 2014-05-05 | C1405-1353 | 0.580 ppm |
| 2014-05-05 | C1405-1354 | 0.840 ppm |
| 2014-06-02 | C1406-1462 | 0.680 ppm |
| 2014-06-02 | C1406-1463 | ND |
| 2014-07-07 | C1407-1628 | 0.920 ppm |
| 2014-07-07 | C1407-1629 | 0.860 ppm |
| 2014-07-16 | B14071638-002A | 0.900 ppm |
| 2014-08-04 | C1408-1716 | 0.800 ppm |
| 2014-08-04 | C1408-1717 | 0.980 ppm |
| 2014-09-02 | C1409-1837 | 0.690 ppm |
| 2014-09-02 | C1409-1838 | 0.760 ppm |
| 2014-10-06 | C1410-2026 | 0.710 ppm |
| 2014-10-06 | C1410-2027 | 0.520 ppm |
| 2014-11-12 | C1411-2163 | 0.720 ppm |
| 2014-11-12 | C1411-2164 | 0.790 ppm |
| 2014-12-01 | C1412-2229 | 0.720 ppm |
| 2014-12-01 | C1412-2230 | 0.960 ppm |
| 2015-01-05 | C1501-0007 | 0.750 ppm |
| 2015-01-05 | C1501-0008 | 0.160 ppm |
| 2015-02-02 | C1502-0192 | 0.800 ppm |
| 2015-02-02 | C1502-0193 | 0.650 ppm |
| 2015-03-02 | C1503-0284 | 0.780 ppm |
| 2015-03-02 | C1503-0285 | 1.06 ppm |
| 2015-04-06 | C1504-0377 | 0.790 ppm |
| 2015-04-06 | C1504-0378 | 0.960 ppm |
| 2015-05-04 | C1505-0488 | 0.760 ppm |
| 2015-05-04 | C1505-0489 | 0.730 ppm |
| 2015-06-01 | C1506-0698 | 0.570 ppm |
| 2015-06-01 | C1506-0699 | 0.780 ppm |
| 2015-07-06 | C1507-0927 | 0.650 ppm |
| 2015-07-06 | C1507-0928 | 0.660 ppm |
| 2015-08-03 | 1508062-01 | 0.760 ppm |
| 2015-08-03 | 1508062-02 | 0.630 ppm |
| 2015-09-01 | 1509031-11 | 0.650 ppm |
| 2015-09-01 | 1509031-12 | 0.780 ppm |
| 2015-10-05 | 1510057-01 | 0.553 ppm |
| 2015-10-05 | 1510057-02 | 0.675 ppm |
| 2015-11-02 | 1511029-01 | 0.646 ppm |
| 2015-11-02 | 1511029-02 | 0.456 ppm |
| 2015-12-01 | 1512042-01 | 0.715 ppm |
| 2015-12-01 | 1512042-02 | 0.469 ppm |
| 2016-01-04 | 1601031-01 | 0.532 ppm |
| 2016-01-04 | 1601031-02 | 0.862 ppm |
| 2016-02-01 | 1602027-01 | 0.427 ppm |
| 2016-02-01 | 1602027-02 | 0.582 ppm |
| 2016-03-01 | 1603034-01 | 0.630 ppm |
| 2016-03-01 | 1603034-02 | 0.786 ppm |
| 2016-04-04 | 1604043-01 | 0.561 ppm |
| 2016-04-04 | 1604043-02 | 0.757 ppm |
| 2016-05-02 | 1605031-01 | 0.590 ppm |
| 2016-05-02 | 1605031-02 | 0.755 ppm |
| 2016-06-06 | 1606090-01 | 0.578 ppm |
| 2016-06-06 | 1606090-02 | 0.765 ppm |
| 2016-07-05 | 1607043-01 | 0.637 ppm |
| 2016-07-05 | 1607043-02 | 0.714 ppm |
| 2016-08-01 | 1608035-01 | 0.619 ppm |
| 2016-08-01 | 1608035-02 | 0.702 ppm |
| 2016-09-06 | 1609089-01 | 0.697 ppm |
| 2016-09-06 | 1609089-02 | 0.565 ppm |
| 2016-10-03 | 1610032-01 | 0.646 ppm |
| 2016-10-03 | 1610032-02 | 0.747 ppm |
| 2016-11-01 | 1611029-01 | 0.533 ppm |
| 2016-11-01 | 1611029-02 | 0.728 ppm |
| 2016-12-05 | 1612059-01 | 0.555 ppm |
| 2016-12-05 | 1612059-02 | 0.508 ppm |
| 2017-01-03 | 1701015-01 | 0.631 ppm |
| 2017-01-03 | 1701015-02 | 0.672 ppm |
| 2017-02-06 | 1702083-01 | 0.709 ppm |
| 2017-02-06 | 1702083-02 | 0.472 ppm |
| 2017-03-06 | 1703074-01 | 0.450 ppm |
| 2017-03-06 | 1703074-02 | 0.649 ppm |
| 2017-04-03 | 1704037-01 | 0.712 ppm |
| 2017-04-03 | 1704037-02 | 0.895 ppm |
| 2017-05-01 | 1705029-01 | 0.619 ppm |
| 2017-05-01 | 1705029-02 | 0.532 ppm |
| 2017-06-05 | 1706065-01 | 0.649 ppm |
| 2017-06-05 | 1706065-02 | 0.576 ppm |
| 2017-06-14 | B17061576-002A | 0.500 ppm |
| 2017-07-05 | 1707037-01 | 0.666 ppm |
| 2017-07-05 | 1707037-02 | 0.688 ppm |
| 2017-08-07 | 1708105-01 | ND |
| 2017-08-07 | 1708105-02 | 0.654 ppm |
| 2017-09-05 | 1709040-01 | 0.719 ppm |
| 2017-09-05 | 1709040-02 | 0.727 ppm |
| 2017-10-02 | 1710025-01 | 0.661 ppm |
| 2017-10-02 | 1710025-02 | 0.123 ppm |
| 2017-11-06 | 1711071-01 | 0.653 ppm |
| 2017-11-06 | 1711071-02 | 0.686 ppm |
| 2017-12-04 | 1712029-01 | 0.681 ppm |
| 2017-12-04 | 1712029-02 | 0.657 ppm |
| 2018-01-02 | 1801011-01 | 0.672 ppm |
| 2018-01-02 | 1801011-02 | 0.758 ppm |
| 2018-02-05 | 1802047-01 | 0.653 ppm |
| 2018-02-05 | 1802047-02 | 0.711 ppm |
| 2018-03-05 | 1803043-01 | 0.666 ppm |
| 2018-03-05 | 1803043-02 | 0.726 ppm |
| 2018-04-02 | 1804014-01 | 0.688 ppm |
| 2018-04-02 | 1804014-02 | 0.693 ppm |
| 2018-05-01 | 1805038-01 | 0.618 ppm |
| 2018-05-01 | 1805038-02 | 0.638 ppm |
| 2018-06-04 | 1806054-01 | 0.663 ppm |
| 2018-06-04 | 1806054-02 | 0.630 ppm |
| 2018-07-02 | 1807036-01 | 0.692 ppm |
| 2018-07-02 | 1807036-02 | 0.683 ppm |
| 2018-08-06 | 1808114-01 | 0.740 ppm |
| 2018-08-06 | 1808114-02 | 0.615 ppm |
| 2018-09-04 | 1809043-01 | 0.659 ppm |
| 2018-09-04 | 1809043-02 | 0.672 ppm |
| 2018-10-01 | 1810013-01 | 0.608 ppm |
| 2018-10-01 | 1810013-02 | 0.653 ppm |
| 2018-11-05 | 1811053-01 | 0.558 ppm |
| 2018-11-05 | 1811053-02 | 0.650 ppm |
| 2018-12-03 | 1812040-01 | 0.649 ppm |
| 2018-12-03 | 1812040-02 | 0.563 ppm |
| 2019-01-07 | 1901095-01 | 0.629 ppm |
| 2019-01-07 | 1901095-02 | 0.547 ppm |
| 2019-02-04 | 1902025-01 | 0.589 ppm |
| 2019-02-04 | 1902025-02 | 0.622 ppm |
| 2019-03-04 | 1903031-01 | 0.617 ppm |
| 2019-03-04 | 1903031-02 | 0.611 ppm |
| 2019-04-01 | 1904026-01 | 0.628 ppm |
| 2019-04-01 | 1904026-02 | 0.616 ppm |
| 2019-05-06 | B19050461-001A | 0.600 ppm |
| 2019-05-06 | B19050461-002A | 0.700 ppm |
| 2019-06-03 | B19060190-001A | 0.700 ppm |
| 2019-06-03 | B19060190-002A | 0.700 ppm |
| 2019-07-08 | B19070711-001A | 0.600 ppm |
| 2019-07-08 | B19070711-002A | 0.700 ppm |
| 2019-08-05 | B19080382-001A | 0.700 ppm |
| 2019-08-05 | B19080382-002A | 0.600 ppm |
| 2019-09-03 | B19090177-001A | 0.800 ppm |
| 2019-09-03 | B19090177-002A | 0.800 ppm |
| 2019-10-01 | B19100196-001A | 0.700 ppm |
| 2019-10-01 | B19100196-002A | 0.700 ppm |
| 2019-11-04 | B19110242-001A | 0.600 ppm |
| 2019-11-04 | B19110242-002A | 0.600 ppm |
| 2019-12-02 | B19120103-001A | 0.600 ppm |
| 2019-12-02 | B19120103-002A | 0.700 ppm |