Fluoride
El Dorado Waterworks
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 | 0.744 ppm | 24 | 24 | 0.410 ppm - 0.900 ppm |
2015 | 0.838 ppm | 25 | 25 | 0.680 ppm - 0.910 ppm |
2016 | 0.895 ppm | 24 | 24 | 0.600 ppm - 1.11 ppm |
2017 | 0.905 ppm | 24 | 24 | 0.290 ppm - 1.06 ppm |
2018 | 0.929 ppm | 26 | 26 | 0.830 ppm - 1.05 ppm |
2019 | 0.915 ppm | 24 | 24 | 0.800 ppm - 1.03 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 |
---|---|---|
2014-01-14 | 140220017 | 0.760 ppm |
2014-01-14 | 140220018 | 0.520 ppm |
2014-02-05 | 140410023 | 0.880 ppm |
2014-02-05 | 140410022 | 0.600 ppm |
2014-03-10 | 140760036 | 0.410 ppm |
2014-03-10 | 140760037 | 0.720 ppm |
2014-04-01 | 141040001 | 0.670 ppm |
2014-04-01 | 141040002 | 0.670 ppm |
2014-05-05 | 141320028 | 0.810 ppm |
2014-05-05 | 141320027 | 0.820 ppm |
2014-06-16 | 141810009 | 0.810 ppm |
2014-06-16 | 141810011 | 0.780 ppm |
2014-07-01 | 141880013 | 0.700 ppm |
2014-07-01 | 141880014 | 0.580 ppm |
2014-08-11 | 142300020 | 0.820 ppm |
2014-08-11 | 142300019 | 0.760 ppm |
2014-09-08 | 142580040 | 0.730 ppm |
2014-09-08 | 142580039 | 0.880 ppm |
2014-10-07 | Y142860026 | 0.890 ppm |
2014-10-07 | Y142860031 | 0.640 ppm |
2014-11-06 | Y143210018 | 0.900 ppm |
2014-11-06 | Y143210017 | 0.840 ppm |
2014-12-02 | Y143420029 | 0.870 ppm |
2014-12-02 | Y143420030 | 0.800 ppm |
2015-01-08 | Y150130065 | 0.870 ppm |
2015-01-08 | Y150130066 | 0.880 ppm |
2015-02-05 | Y150500029 | 0.820 ppm |
2015-02-05 | Y150500030 | 0.860 ppm |
2015-03-02 | Y150690013 | 0.800 ppm |
2015-03-10 | Y150710004 | 0.680 ppm |
2015-04-09 | Y151110010 | 0.800 ppm |
2015-04-09 | Y151110011 | 0.870 ppm |
2015-05-07 | Y151340056 | 0.860 ppm |
2015-05-07 | Y151340057 | 0.850 ppm |
2015-06-23 | Y151800014 | 0.890 ppm |
2015-06-23 | Y151800013 | 0.760 ppm |
2015-07-06 | Y151950004 | 0.830 ppm |
2015-07-06 | Y151950005 | 0.830 ppm |
2015-08-20 | Y152430016 | 0.880 ppm |
2015-08-20 | Y152430017 | 0.880 ppm |
2015-08-25 | Y152390005 | 0.790 ppm |
2015-09-02 | Y152510026 | 0.870 ppm |
2015-09-02 | Y152510025 | 0.880 ppm |
2015-10-07 | Y152850030 | 0.780 ppm |
2015-10-07 | Y152850029 | 0.780 ppm |
2015-11-03 | Y153130035 | 0.810 ppm |
2015-11-03 | Y153130034 | 0.870 ppm |
2015-12-03 | Y153480019 | 0.910 ppm |
2015-12-03 | Y153480018 | 0.910 ppm |
2016-01-13 | Y160200032 | 0.960 ppm |
2016-01-13 | Y160200037 | 0.950 ppm |
2016-02-08 | Y160470046 | 0.880 ppm |
2016-02-08 | Y160470047 | 0.870 ppm |
2016-03-10 | Y160810029 | 0.880 ppm |
2016-03-10 | Y160810030 | 0.860 ppm |
2016-04-12 | Y161060048 | 0.860 ppm |
2016-04-12 | Y161060049 | 0.870 ppm |
2016-05-11 | Y161440002 | 0.890 ppm |
2016-05-11 | Y161440003 | 0.890 ppm |
2016-06-03 | Y161650029 | 0.900 ppm |
2016-06-03 | Y161650030 | 0.940 ppm |
2016-07-14 | Y162070002 | 0.870 ppm |
2016-07-14 | Y162070003 | 1.11 ppm |
2016-08-04 | Y162280004 | 0.600 ppm |
2016-08-04 | Y162280005 | 1.02 ppm |
2016-09-06 | Y162560008 | 0.900 ppm |
2016-09-06 | Y162560009 | 0.840 ppm |
2016-10-06 | Y162880082 | 0.920 ppm |
2016-10-06 | Y162880087 | 0.910 ppm |
2016-11-03 | Y163140028 | 0.880 ppm |
2016-11-03 | Y163140029 | 0.760 ppm |
2016-12-09 | Y163500035 | 0.960 ppm |
2016-12-09 | Y163500036 | 0.960 ppm |
2017-01-03 | Y170100028 | 0.880 ppm |
2017-01-03 | Y170100029 | 0.780 ppm |
2017-02-02 | Y170410010 | 1.000 ppm |
2017-02-02 | Y170410011 | 1.000 ppm |
2017-03-14 | Y170860017 | 1.03 ppm |
2017-03-17 | Y170860018 | 1.03 ppm |
2017-04-04 | Y171000036 | 1.06 ppm |
2017-04-04 | Y171000037 | 0.980 ppm |
2017-05-02 | Y171350021 | 0.970 ppm |
2017-05-02 | Y171350022 | 0.960 ppm |
2017-06-14 | Y171770010 | 0.790 ppm |
2017-06-14 | Y171770011 | 0.940 ppm |
2017-07-06 | Y171980013 | 1.01 ppm |
2017-07-06 | Y171980014 | 1.01 ppm |
2017-08-24 | Y172480008 | 0.950 ppm |
2017-08-24 | Y172480009 | 0.950 ppm |
2017-09-27 | Y172760023 | 0.960 ppm |
2017-09-27 | Y172760024 | 0.950 ppm |
2017-10-23 | Y173030034 | 0.900 ppm |
2017-10-23 | Y173030035 | 0.730 ppm |
2017-11-16 | Y173380004 | 0.290 ppm |
2017-11-16 | Y173380005 | 0.790 ppm |
2017-12-19 | Y173610022 | 0.950 ppm |
2017-12-19 | Y173610023 | 0.820 ppm |
2018-01-11 | Y180180061 | 0.940 ppm |
2018-01-11 | Y180180062 | 0.980 ppm |
2018-02-08 | Y180520023 | 0.920 ppm |
2018-02-08 | Y180520022 | 0.880 ppm |
2018-02-26 | Y180600009 | 0.890 ppm |
2018-03-08 | Y180720025 | 0.930 ppm |
2018-03-08 | Y180720026 | 0.900 ppm |
2018-04-05 | Y180990063 | 0.890 ppm |
2018-04-05 | Y180990062 | 0.990 ppm |
2018-05-04 | Y181300049 | 0.970 ppm |
2018-05-04 | Y181300050 | 0.840 ppm |
2018-06-06 | Y181620039 | 0.910 ppm |
2018-06-06 | Y181620040 | 0.910 ppm |
2018-07-02 | Y181900011 | 0.840 ppm |
2018-07-02 | Y181900012 | 0.850 ppm |
2018-07-30 | Y182140005 | 0.950 ppm |
2018-08-01 | Y182190017 | 0.830 ppm |
2018-08-01 | Y182190016 | 0.830 ppm |
2018-09-06 | Y182530039 | 0.920 ppm |
2018-09-06 | Y182530040 | 1.05 ppm |
2018-10-09 | Y182890035 | 0.960 ppm |
2018-10-09 | Y182890034 | 0.980 ppm |
2018-11-15 | Y183240037 | 1.01 ppm |
2018-11-15 | Y183240038 | 1.02 ppm |
2018-12-06 | Y183440046 | 0.980 ppm |
2018-12-06 | Y183440047 | 0.980 ppm |
2019-01-22 | Y190280018 | 1.02 ppm |
2019-01-22 | Y190280019 | 1.03 ppm |
2019-02-07 | Y190500034 | 1.000 ppm |
2019-02-07 | Y190500032 | 1.000 ppm |
2019-03-07 | Y190770029 | 1.03 ppm |
2019-03-07 | Y190770028 | 0.810 ppm |
2019-04-09 | Y191050029 | 0.960 ppm |
2019-04-09 | Y191050028 | 0.950 ppm |
2019-05-09 | Y191330040 | 0.960 ppm |
2019-05-09 | Y191330041 | 0.940 ppm |
2019-06-19 | Y191750024 | 0.950 ppm |
2019-06-19 | Y191750023 | 0.950 ppm |
2019-07-05 | Y191960018 | 0.880 ppm |
2019-07-05 | Y191960019 | 0.880 ppm |
2019-08-05 | Y192250012 | 0.840 ppm |
2019-08-05 | Y192250011 | 0.840 ppm |
2019-09-11 | Y192590015 | 0.840 ppm |
2019-09-11 | Y192590016 | 0.840 ppm |
2019-10-04 | Y192880039 | 0.860 ppm |
2019-10-04 | Y192880040 | 0.860 ppm |
2019-11-13 | Y193220042 | 0.970 ppm |
2019-11-13 | Y193220041 | 0.960 ppm |
2019-12-04 | Y193470028 | 0.800 ppm |
2019-12-04 | Y193470029 | 0.800 ppm |