Fluoride
Mena Water
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 | 0.516 ppm | 11 | 11 | 0.280 ppm - 0.730 ppm |
| 2015 | 0.729 ppm | 13 | 13 | 0.440 ppm - 1.000 ppm |
| 2016 | 0.952 ppm | 14 | 14 | 0.850 ppm - 1.06 ppm |
| 2017 | 0.966 ppm | 13 | 13 | 0.860 ppm - 1.06 ppm |
| 2018 | 0.995 ppm | 13 | 13 | 0.770 ppm - 1.17 ppm |
| 2019 | 1.03 ppm | 14 | 14 | 0.800 ppm - 1.19 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 |
|---|---|---|
| 2014-03-17 | 140900001 | 0.280 ppm |
| 2014-03-18 | 140790015 | 0.350 ppm |
| 2014-04-23 | 141150013 | 0.390 ppm |
| 2014-05-20 | 141470010 | 0.440 ppm |
| 2014-06-11 | 141740012 | 0.350 ppm |
| 2014-07-16 | 142020012 | 0.650 ppm |
| 2014-08-06 | 142230026 | 0.590 ppm |
| 2014-09-15 | 142650001 | 0.640 ppm |
| 2014-10-06 | Y142860003 | 0.630 ppm |
| 2014-11-12 | Y143210033 | 0.730 ppm |
| 2014-12-08 | Y143490013 | 0.630 ppm |
| 2015-01-13 | Y150200011 | 0.670 ppm |
| 2015-01-13 | Y150150009 | 0.790 ppm |
| 2015-02-18 | Y150610001 | 0.580 ppm |
| 2015-03-03 | Y150690016 | 0.490 ppm |
| 2015-04-07 | Y151030022 | 0.720 ppm |
| 2015-05-19 | Y151420023 | 0.440 ppm |
| 2015-06-10 | Y151670005 | 0.620 ppm |
| 2015-07-07 | Y151890022 | 0.770 ppm |
| 2015-08-04 | Y152180007 | 0.720 ppm |
| 2015-09-16 | Y152650015 | 0.970 ppm |
| 2015-10-06 | Y152850016 | 1.000 ppm |
| 2015-11-03 | Y153130006 | 1.000 ppm |
| 2015-12-16 | Y153520047 | 0.710 ppm |
| 2016-01-20 | Y160270020 | 0.980 ppm |
| 2016-02-03 | Y160350004 | 0.940 ppm |
| 2016-02-04 | Y160400016 | 1.000 ppm |
| 2016-02-17 | Y160490003 | 0.970 ppm |
| 2016-03-08 | Y160740012 | 0.910 ppm |
| 2016-04-05 | Y161040019 | 1.01 ppm |
| 2016-05-04 | Y161300005 | 0.890 ppm |
| 2016-06-06 | Y161650004 | 0.960 ppm |
| 2016-07-07 | Y161930018 | 0.850 ppm |
| 2016-08-09 | Y162280001 | 0.860 ppm |
| 2016-09-12 | Y162640004 | 0.920 ppm |
| 2016-10-11 | Y162880077 | 1.06 ppm |
| 2016-11-16 | Y163260017 | 1.03 ppm |
| 2016-12-13 | Y163500006 | 0.950 ppm |
| 2017-01-09 | Y170120002 | 0.920 ppm |
| 2017-01-10 | Y170110002 | 0.970 ppm |
| 2017-02-07 | Y170410001 | 0.980 ppm |
| 2017-03-07 | Y170720038 | 0.890 ppm |
| 2017-04-12 | Y171070029 | 0.960 ppm |
| 2017-05-09 | Y171350054 | 0.950 ppm |
| 2017-06-13 | Y171700022 | 0.890 ppm |
| 2017-07-19 | Y172050032 | 1.05 ppm |
| 2017-08-21 | Y172400010 | 1.06 ppm |
| 2017-09-11 | Y172610007 | 1.06 ppm |
| 2017-10-18 | Y172960024 | 0.990 ppm |
| 2017-11-01 | Y173100005 | 0.860 ppm |
| 2017-12-05 | Y173450020 | 0.980 ppm |
| 2018-01-09 | Y180110004 | 0.930 ppm |
| 2018-01-16 | Y180180066 | 0.770 ppm |
| 2018-02-21 | Y180530038 | 0.920 ppm |
| 2018-03-20 | Y180850017 | 1.06 ppm |
| 2018-04-09 | Y181070015 | 0.990 ppm |
| 2018-05-08 | Y181340019 | 0.930 ppm |
| 2018-06-13 | Y181690022 | 1.06 ppm |
| 2018-07-10 | Y181970045 | 0.880 ppm |
| 2018-08-07 | Y182250018 | 1.08 ppm |
| 2018-09-17 | Y182670029 | 1.06 ppm |
| 2018-10-09 | Y182890019 | 0.960 ppm |
| 2018-11-06 | Y183170010 | 1.13 ppm |
| 2018-12-03 | Y183440002 | 1.17 ppm |
| 2019-01-03 | Y190040001 | 0.800 ppm |
| 2019-01-14 | Y190170018 | 1.10 ppm |
| 2019-01-15 | Y190220021 | 1.05 ppm |
| 2019-02-19 | Y190560011 | 0.950 ppm |
| 2019-03-18 | Y190840003 | 0.940 ppm |
| 2019-04-16 | Y191120011 | 0.940 ppm |
| 2019-05-23 | Y191530030 | 1.04 ppm |
| 2019-06-20 | Y191750022 | 1.05 ppm |
| 2019-07-15 | Y192030001 | 1.12 ppm |
| 2019-08-06 | Y192250030 | 1.05 ppm |
| 2019-09-10 | Y192540044 | 1.05 ppm |
| 2019-10-02 | Y192880031 | 1.02 ppm |
| 2019-11-07 | Y193220030 | 1.19 ppm |
| 2019-12-04 | Y193430033 | 1.09 ppm |