Fluoride
Pomona Water Department
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 | 0.295 ppm | 25 | 25 | 0.120 ppm - 0.530 ppm |
| 2015 | 0.273 ppm | 20 | 20 | 0.140 ppm - 0.480 ppm |
| 2016 | 0.311 ppm | 12 | 12 | 0.220 ppm - 0.550 ppm |
| 2017 | 0.276 ppm | 18 | 18 | 0.120 ppm - 0.500 ppm |
| 2018 | 0.276 ppm | 21 | 21 | 0.150 ppm - 0.420 ppm |
| 2019 | 0.283 ppm | 15 | 15 | 0.200 ppm - 0.390 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 |
|---|---|---|
| 2014-01-02 | 9590-042-1105 | 0.430 ppm |
| 2014-01-06 | 9590-033-1012 | 0.390 ppm |
| 2014-01-06 | 9590-038-1046 | 0.210 ppm |
| 2014-02-27 | 9590-051-1000 | 0.280 ppm |
| 2014-03-18 | 9590-013-0955 | 0.370 ppm |
| 2014-03-26 | 9590-036-0957 | 0.330 ppm |
| 2014-04-02 | 9590-015-1003 | 0.220 ppm |
| 2014-04-02 | 9590-023-0906 | 0.270 ppm |
| 2014-04-08 | 9590-021-0838 | 0.280 ppm |
| 2014-04-09 | 9590-071-0935 | 0.240 ppm |
| 2014-05-20 | 9590-050-0915 | 0.120 ppm |
| 2014-06-10 | 9590-028-0740 | 0.320 ppm |
| 2014-06-24 | 9590-007-0940 | 0.120 ppm |
| 2014-06-30 | 9590-031-0940 | 0.510 ppm |
| 2014-07-02 | 9590-032-0813 | 0.310 ppm |
| 2014-07-07 | 9590-033-0847 | 0.530 ppm |
| 2014-07-07 | 9590-038-0945 | 0.240 ppm |
| 2014-07-07 | 9590-042-1135 | 0.390 ppm |
| 2014-07-16 | 9590-002-0828 | 0.260 ppm |
| 2014-07-16 | 9590-010-0925 | 0.260 ppm |
| 2014-07-16 | 9590-052-0856 | 0.240 ppm |
| 2014-08-28 | 9590-027-0930 | 0.250 ppm |
| 2014-10-06 | 9590-071-0918 | 0.240 ppm |
| 2014-11-03 | 9590-069-1122 | 0.240 ppm |
| 2014-12-09 | 9590-035-0943 | 0.320 ppm |
| 2015-01-05 | 9590-033-1052 | 0.250 ppm |
| 2015-01-05 | 9590-038-0946 | 0.210 ppm |
| 2015-01-05 | 9590-042-1030 | 0.380 ppm |
| 2015-02-12 | 9590-041-0750 | 0.140 ppm |
| 2015-02-25 | 9590-049-0949 | 0.190 ppm |
| 2015-02-26 | 9590-036-0922 | 0.340 ppm |
| 2015-03-31 | 9590-025-1023 | 0.190 ppm |
| 2015-04-06 | 9590-071-1131 | 0.230 ppm |
| 2015-04-16 | 9590-040-0810 | 0.280 ppm |
| 2015-04-21 | 9590-016-0920 | 0.230 ppm |
| 2015-05-20 | 9590-031-1017 | 0.320 ppm |
| 2015-06-10 | 9590-028-0844 | 0.300 ppm |
| 2015-07-06 | 9590-038-0857 | 0.240 ppm |
| 2015-07-06 | 9590-042-0959 | 0.320 ppm |
| 2015-07-07 | 9590-017-0905 | 0.230 ppm |
| 2015-07-08 | 9590-032-0815 | 0.480 ppm |
| 2015-07-09 | 9590-027-0910 | 0.200 ppm |
| 2015-08-10 | 9590-033-1005 | 0.340 ppm |
| 2015-10-05 | 9590-071-1040 | 0.240 ppm |
| 2015-10-20 | 9590-035-1021 | 0.340 ppm |
| 2016-01-04 | 9590-042-1250 | 0.360 ppm |
| 2016-01-06 | 9590-033-0947 | 0.320 ppm |
| 2016-01-11 | 9590-038-0907 | 0.220 ppm |
| 2016-01-12 | 9590-036-0850 | 0.340 ppm |
| 2016-04-04 | 9590-071-1009 | 0.220 ppm |
| 2016-05-16 | 9590-031-1000 | 0.550 ppm |
| 2016-06-02 | 9590-028-1115 | 0.310 ppm |
| 2016-07-05 | 9590-038-0954 | 0.230 ppm |
| 2016-07-14 | 9590-033-1000 | 0.440 ppm |
| 2016-07-14 | 9590-042-0845 | 0.280 ppm |
| 2016-07-20 | 9590-027-0945 | 0.220 ppm |
| 2016-10-12 | 9590-071-0942 | 0.240 ppm |
| 2017-01-04 | 9590-033-1130 | 0.300 ppm |
| 2017-01-05 | 9590-038-1015 | 0.260 ppm |
| 2017-01-25 | 9590-051-0910 | 0.290 ppm |
| 2017-03-09 | 9590-042-1005 | 0.340 ppm |
| 2017-04-06 | 9590-071-1145 | 0.270 ppm |
| 2017-04-13 | 9590-050-1030 | 0.120 ppm |
| 2017-04-20 | 9590-023-1245 | 0.230 ppm |
| 2017-05-17 | 9590-036-1045 | 0.310 ppm |
| 2017-07-11 | 9590-038-1040 | 0.250 ppm |
| 2017-07-13 | 9590-033-0930 | 0.500 ppm |
| 2017-07-13 | 9590-042-1150 | 0.290 ppm |
| 2017-07-20 | 9590-010-1356 | 0.240 ppm |
| 2017-07-24 | 9590-027-1415 | 0.200 ppm |
| 2017-07-25 | 9590-052-1445 | 0.250 ppm |
| 2017-10-19 | 9590-069-1035 | 0.250 ppm |
| 2017-10-19 | 9590-071-1052 | 0.250 ppm |
| 2017-10-25 | 9590-032-1115 | 0.390 ppm |
| 2017-12-21 | 9590-006-1240 | 0.230 ppm |
| 2018-01-04 | 9590-033-1301 | 0.270 ppm |
| 2018-01-11 | 9590-038-1325 | 0.240 ppm |
| 2018-01-18 | 9590-042-1313 | 0.360 ppm |
| 2018-02-15 | 9590-049-0903 | 0.180 ppm |
| 2018-02-16 | 9590-021-1310 | 0.280 ppm |
| 2018-02-16 | 9590-025-1219 | 0.190 ppm |
| 2018-02-16 | 9590-026-1242 | 0.250 ppm |
| 2018-04-16 | 9590-071-0956 | 0.250 ppm |
| 2018-04-18 | 9590-040-1330 | 0.310 ppm |
| 2018-04-25 | 9590-016-1025 | 0.240 ppm |
| 2018-05-23 | 9590-028-1006 | 0.280 ppm |
| 2018-06-13 | 9590-063-0955 | 0.350 ppm |
| 2018-06-20 | 9590-041-1035 | 0.150 ppm |
| 2018-07-11 | 9590-033-1309 | 0.420 ppm |
| 2018-07-16 | 9590-038-1333 | 0.240 ppm |
| 2018-07-17 | 9590-042-1055 | 0.330 ppm |
| 2018-07-18 | 9590-027-1408 | 0.220 ppm |
| 2018-07-19 | 9590-031-0951 | 0.380 ppm |
| 2018-07-25 | 9590-017-0845 | 0.220 ppm |
| 2018-10-23 | 9590-071-0935 | 0.240 ppm |
| 2018-12-06 | 9590-063-0820 | 0.400 ppm |
| 2019-01-09 | 9590-033-1045 | 0.230 ppm |
| 2019-01-23 | 9590-038-0843 | 0.240 ppm |
| 2019-01-29 | 9590-042-1256 | 0.350 ppm |
| 2019-01-30 | 9590-032-0915 | 0.330 ppm |
| 2019-04-04 | 9590-071-0901 | 0.210 ppm |
| 2019-04-17 | 9590-035-1010 | 0.350 ppm |
| 2019-04-17 | 9590-036-1005 | 0.320 ppm |
| 2019-04-17 | 9590-063-1354 | 0.390 ppm |
| 2019-07-02 | 9590-042-1220 | 0.340 ppm |
| 2019-07-03 | 9590-038-1400 | 0.200 ppm |
| 2019-07-10 | 9590-031-1326 | 0.310 ppm |
| 2019-07-18 | 9590-027-1156 | 0.210 ppm |
| 2019-09-26 | 9590-002-1030 | 0.230 ppm |
| 2019-10-03 | 9590-063-1340 | 0.330 ppm |
| 2019-10-10 | 9590-071-1316 | 0.210 ppm |