Fluoride

City of Escondido

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.

MORE ABOUT THIS CONTAMINANT

127

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	0.499 ppm	8	8	0.210 ppm - 0.860 ppm
2015	0.508 ppm	9	9	0.270 ppm - 0.850 ppm
2016	0.499 ppm	8	8	0.270 ppm - 0.700 ppm
2017	0.504 ppm	5	5	0.150 ppm - 0.690 ppm
2018	0.658 ppm	33	33	0.180 ppm - 0.770 ppm
2019	0.672 ppm	64	64	0.150 ppm - 0.790 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
2014-02-10	2706-018-1028	0.540 ppm
2014-02-10	2706-019-1012	0.300 ppm
2014-05-12	2706-018-1022	0.860 ppm
2014-05-12	2706-019-1001	0.340 ppm
2014-08-18	2706-018-1148	0.730 ppm
2014-08-18	2706-019-1126	0.210 ppm
2014-11-17	2706-018-1110	0.710 ppm
2014-11-17	2706-019-1043	0.300 ppm
2015-02-09	2706-018-1120	0.850 ppm
2015-02-17	2706-019-0852	0.340 ppm
2015-05-18	2706-018-1110	0.720 ppm
2015-05-18	2706-019-1010	0.270 ppm
2015-07-14	9209-019-0940	0.290 ppm
2015-08-17	2706-018-1120	0.730 ppm
2015-08-17	2706-019-1029	0.290 ppm
2015-11-16	2706-018-1104	0.730 ppm
2015-11-16	2706-019-1038	0.350 ppm
2016-02-23	2706-018-1020	0.690 ppm
2016-02-23	2706-019-0952	0.310 ppm
2016-05-16	2706-018-1010	0.670 ppm
2016-05-16	2706-019-0919	0.320 ppm
2016-08-15	2706-018-1013	0.700 ppm
2016-08-15	2706-019-0955	0.270 ppm
2016-11-14	2706-018-1028	0.700 ppm
2016-11-14	2706-019-0953	0.330 ppm
2017-02-13	2706-018-1144	0.670 ppm
2017-02-13	2706-019-1107	0.350 ppm
2017-05-09	2706-018-1050	0.690 ppm
2017-11-13	2706-018-0730	0.660 ppm
2017-11-13	2706-019-0843	0.150 ppm
2018-02-13	2706-018-0930	0.680 ppm
2018-02-13	2706-019-0900	0.180 ppm
2018-05-15	2706-018-0838	0.700 ppm
2018-05-15	2706-019-0916	0.330 ppm
2018-08-06	9209-018-1030	0.720 ppm
2018-08-14	9209-018-0842	0.720 ppm
2018-08-14	2706-018-0900	0.690 ppm
2018-08-14	2706-019-0935	0.250 ppm
2018-08-14	9209-900-1049	0.730 ppm
2018-08-14	9209-903-1032	0.740 ppm
2018-08-14	9209-908-1025	0.730 ppm
2018-09-04	9209-018-0940	0.690 ppm
2018-09-11	9209-018-0815	0.650 ppm
2018-09-11	9209-900-0856	0.630 ppm
2018-09-11	9209-903-0724	0.680 ppm
2018-09-11	9209-908-0735	0.670 ppm
2018-10-01	9209-018-0950	0.770 ppm
2018-10-09	9209-018-0725	0.740 ppm
2018-10-09	9209-900-0814	0.750 ppm
2018-10-09	9209-903-0700	0.750 ppm
2018-10-09	9209-908-0712	0.750 ppm
2018-11-05	9209-018-0950	0.770 ppm
2018-11-13	9209-018-0707	0.720 ppm
2018-11-13	2706-018-1035	0.680 ppm
2018-11-13	2706-019-1110	0.260 ppm
2018-11-13	9209-900-0808	0.760 ppm
2018-11-13	9209-903-0640	0.750 ppm
2018-11-13	9209-908-0651	0.750 ppm
2018-12-03	9209-018-0925	0.760 ppm
2018-12-11	9209-018-0730	0.640 ppm
2018-12-11	9209-900-0805	0.700 ppm
2018-12-11	9209-903-0650	0.690 ppm
2018-12-11	9209-908-0702	0.680 ppm
2019-01-07	9209-018-0910	0.710 ppm
2019-01-15	9209-018-0738	0.670 ppm
2019-01-15	9209-900-0820	0.700 ppm
2019-01-15	9209-903-0714	0.670 ppm
2019-01-15	9209-908-0723	0.690 ppm
2019-02-04	9209-018-0900	0.660 ppm
2019-02-19	9209-018-0803	0.640 ppm
2019-02-19	9209-900-0845	0.650 ppm
2019-02-19	9209-903-0738	0.650 ppm
2019-02-19	9209-908-0751	0.670 ppm
2019-03-04	9209-018-1050	0.670 ppm
2019-03-11	9209-018-0759	0.620 ppm
2019-03-11	9209-900-0851	0.660 ppm
2019-03-11	9209-903-0722	0.640 ppm
2019-03-11	9209-908-0743	0.630 ppm
2019-04-01	9209-018-1038	0.670 ppm
2019-04-09	9209-018-0805	0.720 ppm
2019-04-09	9209-900-0858	0.690 ppm
2019-04-09	9209-903-0735	0.710 ppm
2019-04-09	9209-908-0747	0.700 ppm
2019-05-06	9209-018-1015	0.680 ppm
2019-05-13	2706-018-0830	0.570 ppm
2019-05-14	9209-018-0745	0.680 ppm
2019-05-14	9209-900-0838	0.730 ppm
2019-05-14	9209-903-0714	0.700 ppm
2019-05-14	9209-908-0727	0.700 ppm
2019-06-03	9209-018-0955	0.680 ppm
2019-06-18	9209-018-0812	0.620 ppm
2019-06-18	9209-900-0855	0.620 ppm
2019-06-18	9209-903-0745	0.590 ppm
2019-06-18	9209-908-0758	0.640 ppm
2019-07-01	9209-018-0905	0.680 ppm
2019-07-16	9209-018-0750	0.670 ppm
2019-07-16	9209-900-0840	0.700 ppm
2019-07-16	9209-903-0709	0.690 ppm
2019-07-16	9209-908-0722	0.680 ppm
2019-08-05	9209-018-0855	0.700 ppm
2019-08-12	2706-018-0845	0.680 ppm
2019-08-13	9209-018-0730	0.710 ppm
2019-08-13	9209-900-0841	0.740 ppm
2019-08-13	9209-903-0651	0.740 ppm
2019-08-13	9209-908-0703	0.720 ppm
2019-09-04	9209-018-0810	0.760 ppm
2019-09-10	9209-018-0730	0.770 ppm
2019-09-10	9209-900-0825	0.780 ppm
2019-09-10	9209-903-0654	0.790 ppm
2019-09-10	9209-908-0706	0.760 ppm
2019-10-07	9209-018-0850	0.740 ppm
2019-10-08	9209-018-0720	0.710 ppm
2019-10-08	9209-900-0822	0.690 ppm
2019-10-08	9209-903-0655	0.710 ppm
2019-10-08	9209-908-0705	0.720 ppm
2019-11-04	9209-018-0910	0.660 ppm
2019-11-12	9209-018-0740	0.660 ppm
2019-11-12	2706-018-0845	0.620 ppm
2019-11-12	2706-019-0800	0.150 ppm
2019-11-12	9209-900-0830	0.640 ppm
2019-11-12	9209-903-0704	0.680 ppm
2019-11-12	9209-908-0718	0.630 ppm
2019-12-02	9209-018-0925	0.630 ppm
2019-12-10	9209-018-0750	0.640 ppm
2019-12-10	9209-900-0825	0.660 ppm
2019-12-10	9209-903-0710	0.630 ppm
2019-12-10	9209-908-0720	0.640 ppm