Fluoride
Boulder City
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 |
|---|---|---|---|---|
| 2014 | 0.711 ppm | 16 | 16 | 0.690 ppm - 0.740 ppm |
| 2015 | 0.691 ppm | 16 | 16 | 0.660 ppm - 0.720 ppm |
| 2016 | 0.676 ppm | 16 | 16 | 0.650 ppm - 0.690 ppm |
| 2017 | 0.700 ppm | 16 | 16 | 0.650 ppm - 0.739 ppm |
| 2018 | 0.703 ppm | 16 | 16 | 0.666 ppm - 0.735 ppm |
| 2019 | 0.722 ppm | 16 | 16 | 0.689 ppm - 0.740 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 |
|---|---|---|
| 2014-01-08 | 14010106-004 | 0.730 ppm |
| 2014-01-08 | 14010106-003 | 0.730 ppm |
| 2014-01-08 | 14010106-001 | 0.740 ppm |
| 2014-01-08 | 14010106-002 | 0.720 ppm |
| 2014-04-10 | 14040151-001 | 0.710 ppm |
| 2014-04-10 | 14040151-002 | 0.700 ppm |
| 2014-04-10 | 14040151-003 | 0.700 ppm |
| 2014-04-10 | 14040151-004 | 0.700 ppm |
| 2014-07-10 | 14070152-001 | 0.690 ppm |
| 2014-07-10 | 14070152-002 | 0.710 ppm |
| 2014-07-10 | 14070152-003 | 0.710 ppm |
| 2014-07-10 | 14070152-004 | 0.710 ppm |
| 2014-10-09 | 14100139-002 | 0.700 ppm |
| 2014-10-09 | 14100139-001 | 0.710 ppm |
| 2014-10-09 | 14100139-004 | 0.710 ppm |
| 2014-10-09 | 14100139-003 | 0.710 ppm |
| 2015-01-08 | 15010078-004 | 0.710 ppm |
| 2015-01-08 | 15010078-003 | 0.700 ppm |
| 2015-01-08 | 15010078-002 | 0.710 ppm |
| 2015-01-08 | 15010078-001 | 0.710 ppm |
| 2015-04-09 | 15040147-003 | 0.690 ppm |
| 2015-04-09 | 15040147-004 | 0.690 ppm |
| 2015-04-09 | 15040147-002 | 0.700 ppm |
| 2015-04-09 | 15040147-001 | 0.690 ppm |
| 2015-07-09 | 15070197-003 | 0.700 ppm |
| 2015-07-09 | 15070197-002 | 0.700 ppm |
| 2015-07-09 | 15070197-001 | 0.720 ppm |
| 2015-07-09 | 15070197-004 | 0.700 ppm |
| 2015-10-13 | 15100178-001 | 0.660 ppm |
| 2015-10-13 | 15100178-004 | 0.660 ppm |
| 2015-10-13 | 15100178-003 | 0.660 ppm |
| 2015-10-13 | 15100178-002 | 0.660 ppm |
| 2016-01-13 | 16010171-003 | 0.660 ppm |
| 2016-01-13 | 16010171-004 | 0.660 ppm |
| 2016-01-13 | 16010171-002 | 0.660 ppm |
| 2016-01-13 | 16010171-001 | 0.650 ppm |
| 2016-04-12 | 16040165-003 | 0.690 ppm |
| 2016-04-12 | 16040165-002 | 0.680 ppm |
| 2016-04-12 | 16040165-001 | 0.680 ppm |
| 2016-04-12 | 16040165-004 | 0.690 ppm |
| 2016-07-12 | S1601212003 | 0.680 ppm |
| 2016-07-12 | S1601212002 | 0.673 ppm |
| 2016-07-12 | S1601212001 | 0.677 ppm |
| 2016-07-25 | S1602376003 | 0.664 ppm |
| 2016-10-10 | S1604769004 | 0.689 ppm |
| 2016-10-10 | S1604769003 | 0.686 ppm |
| 2016-10-10 | S1604769002 | 0.686 ppm |
| 2016-10-10 | S1604769001 | 0.689 ppm |
| 2017-01-12 | S1700106004 | 0.659 ppm |
| 2017-01-12 | S1700106003 | 0.656 ppm |
| 2017-01-12 | S1700106002 | 0.650 ppm |
| 2017-01-12 | S1700106001 | 0.650 ppm |
| 2017-04-11 | S1700490001 | 0.693 ppm |
| 2017-04-11 | S1700490003 | 0.693 ppm |
| 2017-04-11 | S1700490002 | 0.699 ppm |
| 2017-04-11 | S1700490004 | 0.693 ppm |
| 2017-07-12 | S1702355001 | 0.739 ppm |
| 2017-07-12 | S1702355002 | 0.725 ppm |
| 2017-07-12 | S1702355003 | 0.729 ppm |
| 2017-07-12 | S1702355004 | 0.729 ppm |
| 2017-10-09 | S1704821001 | 0.721 ppm |
| 2017-10-09 | S1704821002 | 0.721 ppm |
| 2017-10-09 | S1704821003 | 0.728 ppm |
| 2017-10-09 | S1704821004 | 0.721 ppm |
| 2018-01-09 | S1708627004 | 0.701 ppm |
| 2018-01-09 | S1708627003 | 0.704 ppm |
| 2018-01-09 | S1708627002 | 0.710 ppm |
| 2018-01-09 | S1708627001 | 0.704 ppm |
| 2018-04-10 | S1800449004 | 0.677 ppm |
| 2018-04-10 | S1800449001 | 0.667 ppm |
| 2018-04-10 | S1800449002 | 0.668 ppm |
| 2018-04-10 | S1800449003 | 0.666 ppm |
| 2018-07-09 | S1802496004 | 0.720 ppm |
| 2018-07-09 | S1802496003 | 0.716 ppm |
| 2018-07-09 | S1802496002 | 0.716 ppm |
| 2018-07-09 | S1802496001 | 0.735 ppm |
| 2018-10-10 | S1804596001 | 0.724 ppm |
| 2018-10-10 | S1804596002 | 0.704 ppm |
| 2018-10-10 | S1804596003 | 0.720 ppm |
| 2018-10-10 | S1804596004 | 0.717 ppm |
| 2019-01-15 | S1807027001 | 0.737 ppm |
| 2019-01-15 | S1807027002 | 0.721 ppm |
| 2019-01-15 | S1807027003 | 0.724 ppm |
| 2019-01-15 | S1807027004 | 0.733 ppm |
| 2019-04-10 | S1904110006 | 0.731 ppm |
| 2019-04-10 | S1904110009 | 0.689 ppm |
| 2019-04-10 | S1904110008 | 0.716 ppm |
| 2019-04-10 | S1904110007 | 0.719 ppm |
| 2019-07-10 | S1917181002 | 0.717 ppm |
| 2019-07-10 | S1917181004 | 0.703 ppm |
| 2019-07-10 | S1917181003 | 0.714 ppm |
| 2019-07-10 | S1917181001 | 0.721 ppm |
| 2019-10-09 | S1947992004 | 0.734 ppm |
| 2019-10-09 | S1947992003 | 0.725 ppm |
| 2019-10-09 | S1947992002 | 0.740 ppm |
| 2019-10-09 | S1947992001 | 0.728 ppm |