Fluoride

City of Clovis

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.

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185

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	0.108 ppm	31	26	ND - 0.170 ppm
2015	0.102 ppm	31	25	ND - 0.180 ppm
2016	0.143 ppm	31	30	ND - 0.220 ppm
2017	0.135 ppm	32	30	ND - 0.240 ppm
2018	0.146 ppm	29	29	0.110 ppm - 0.210 ppm
2019	0.135 ppm	31	30	ND - 0.180 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
2014-08-06	5810-067-0900	ND
2014-09-02	5810-074-1310	0.130 ppm
2014-09-04	5810-048-1210	0.120 ppm
2014-09-04	5810-072-1030	0.110 ppm
2014-09-08	5810-033-0840	0.120 ppm
2014-09-08	5810-034-0930	0.110 ppm
2014-09-10	5810-031-1100	0.140 ppm
2014-09-10	5810-032-1015	0.160 ppm
2014-09-10	5810-082-1015	0.110 ppm
2014-09-11	5810-012-0945	0.120 ppm
2014-09-11	5810-014-0845	0.1000 ppm
2014-09-12	5810-005-0949	0.110 ppm
2014-09-12	5810-019-0851	0.110 ppm
2014-09-12	5810-035-1024	0.120 ppm
2014-09-12	5810-036-1130	0.130 ppm
2014-09-12	5810-040-0925	0.120 ppm
2014-09-15	5810-018-0822	ND
2014-09-15	5810-049-1042	ND
2014-09-15	5810-050-0947	ND
2014-09-15	5810-054-0939	0.110 ppm
2014-09-15	5810-070-1025	0.150 ppm
2014-09-17	5810-046-0834	0.110 ppm
2014-09-17	5810-068-0857	0.160 ppm
2014-09-17	5810-076-0957	0.140 ppm
2014-09-18	5810-024-1050	0.170 ppm
2014-09-18	5810-026-0954	0.140 ppm
2014-09-19	5810-025-1036	0.170 ppm
2014-09-22	5810-016-1017	0.140 ppm
2014-09-23	5810-020-1106	ND
2014-09-23	5810-077-1040	0.110 ppm
2014-09-30	5810-052-1105	0.130 ppm
2015-08-06	5810-067-1015	ND
2015-09-03	5810-018-0846	ND
2015-09-09	5810-005-1044	0.110 ppm
2015-09-09	5810-019-1015	0.130 ppm
2015-09-09	5810-032-0936	0.140 ppm
2015-09-09	5810-033-0758	0.110 ppm
2015-09-09	5810-034-0816	0.110 ppm
2015-09-09	5810-040-1001	0.130 ppm
2015-09-09	5810-046-1028	0.110 ppm
2015-09-11	5810-020-0955	ND
2015-09-11	5810-048-0920	0.130 ppm
2015-09-11	5810-070-1045	ND
2015-09-14	5810-026-1031	0.160 ppm
2015-09-15	5810-014-0800	0.110 ppm
2015-09-15	5810-052-0911	0.120 ppm
2015-09-15	5810-077-0851	0.110 ppm
2015-09-15	5810-082-0830	0.110 ppm
2015-09-16	5810-012-0815	0.110 ppm
2015-09-16	5810-031-0850	0.120 ppm
2015-09-16	5810-035-1055	0.110 ppm
2015-09-16	5810-036-1026	0.130 ppm
2015-09-16	5810-049-0914	0.1000 ppm
2015-09-16	5810-050-0830	0.1000 ppm
2015-09-16	5810-074-0915	0.160 ppm
2015-09-16	5810-076-1033	ND
2015-09-18	5810-024-0922	0.160 ppm
2015-09-18	5810-054-1031	0.120 ppm
2015-09-21	5810-072-0945	0.130 ppm
2015-09-23	5810-068-0947	0.150 ppm
2015-09-25	5810-025-1234	0.180 ppm
2015-09-28	5810-016-1023	ND
2016-08-05	5810-067-0900	ND
2016-09-08	5810-005-0907	0.130 ppm
2016-09-08	5810-014-0800	0.140 ppm
2016-09-08	5810-019-1020	0.150 ppm
2016-09-08	5810-024-0928	0.200 ppm
2016-09-08	5810-025-1035	0.220 ppm
2016-09-08	5810-026-0856	0.180 ppm
2016-09-08	5810-040-0900	0.140 ppm
2016-09-08	5810-046-0756	0.140 ppm
2016-09-08	5810-068-0928	0.190 ppm
2016-09-08	5810-070-0815	0.190 ppm
2016-09-08	5810-077-0951	0.130 ppm
2016-09-09	5810-012-0950	0.130 ppm
2016-09-09	5810-018-0730	0.110 ppm
2016-09-09	5810-031-0847	0.150 ppm
2016-09-09	5810-032-0815	0.160 ppm
2016-09-09	5810-033-0730	0.120 ppm
2016-09-09	5810-034-0753	0.120 ppm
2016-09-09	5810-035-1038	0.140 ppm
2016-09-09	5810-036-1126	0.170 ppm
2016-09-09	5810-048-0900	0.190 ppm
2016-09-09	5810-052-0908	0.140 ppm
2016-09-09	5810-076-0925	0.150 ppm
2016-09-09	5810-082-0845	0.130 ppm
2016-09-12	5810-050-0955	0.130 ppm
2016-09-12	5810-054-1030	0.140 ppm
2016-09-12	5810-074-1103	0.160 ppm
2016-09-14	5810-016-0923	0.150 ppm
2016-09-14	5810-020-0805	0.1000 ppm
2016-09-14	5810-049-0900	0.110 ppm
2016-09-21	5810-072-1100	0.120 ppm
2017-08-03	5810-067-0850	ND
2017-09-07	5810-050-0650	0.130 ppm
2017-09-07	5810-070-0707	0.180 ppm
2017-09-07	5810-076-1130	0.150 ppm
2017-09-08	5810-054-0725	0.130 ppm
2017-09-08	5810-074-0700	0.160 ppm
2017-09-11	5810-005-0714	0.120 ppm
2017-09-11	5810-035-0635	0.130 ppm
2017-09-11	5810-036-0648	0.150 ppm
2017-09-12	5810-020-0642	0.110 ppm
2017-09-12	5810-032-0700	0.160 ppm
2017-09-12	5810-033-0745	0.120 ppm
2017-09-12	5810-034-0810	0.120 ppm
2017-09-12	5810-048-0950	0.150 ppm
2017-09-12	5810-068-0701	0.170 ppm
2017-09-12	5810-082-0935	0.130 ppm
2017-09-13	5810-018-1030	0.110 ppm
2017-09-13	5810-031-0735	0.140 ppm
2017-09-13	5810-049-0900	0.110 ppm
2017-09-14	5810-012-0850	0.140 ppm
2017-09-14	5810-019-0740	0.140 ppm
2017-09-14	5810-024-1225	0.190 ppm
2017-09-18	5810-016-1010	0.150 ppm
2017-09-18	5810-040-0916	0.180 ppm
2017-09-18	5810-052-0815	0.130 ppm
2017-09-18	5810-077-0945	0.130 ppm
2017-09-20	5810-025-1330	0.240 ppm
2017-09-20	5810-026-1250	0.170 ppm
2017-09-20	5810-046-1115	0.130 ppm
2017-09-20	5810-072-1000	0.120 ppm
2017-10-26	5810-014-0820	0.140 ppm
2017-11-03	5810-014-0815	ND
2018-09-05	5810-018-1025	0.120 ppm
2018-09-06	5810-005-0724	0.120 ppm
2018-09-06	5810-012-0750	0.140 ppm
2018-09-06	5810-019-0845	0.140 ppm
2018-09-06	5810-031-0654	0.150 ppm
2018-09-06	5810-032-0940	0.160 ppm
2018-09-06	5810-033-0925	0.130 ppm
2018-09-06	5810-040-1015	0.140 ppm
2018-09-06	5810-049-0849	0.110 ppm
2018-09-06	5810-054-0821	0.140 ppm
2018-09-06	5810-068-0737	0.190 ppm
2018-09-06	5810-070-0743	0.180 ppm
2018-09-06	5810-074-0856	0.160 ppm
2018-09-07	5810-014-0915	0.130 ppm
2018-09-07	5810-024-0726	0.200 ppm
2018-09-07	5810-034-0740	0.130 ppm
2018-09-07	5810-035-0749	0.130 ppm
2018-09-07	5810-046-0800	0.130 ppm
2018-09-07	5810-048-0810	0.150 ppm
2018-09-07	5810-050-0707	0.120 ppm
2018-09-07	5810-082-0710	0.130 ppm
2018-09-11	5810-025-1128	0.210 ppm
2018-09-11	5810-026-0722	0.170 ppm
2018-09-11	5810-077-1046	0.120 ppm
2018-09-12	5810-016-0928	0.180 ppm
2018-09-12	5810-036-0805	0.150 ppm
2018-09-12	5810-052-0900	0.120 ppm
2018-09-12	5810-076-0822	0.150 ppm
2018-09-19	5810-072-1026	0.130 ppm
2019-07-03	5810-024-0726	0.170 ppm
2019-07-03	5810-040-1005	0.130 ppm
2019-07-03	5810-070-0751	0.160 ppm
2019-07-05	5810-014-0814	0.140 ppm
2019-07-05	5810-035-0733	0.150 ppm
2019-07-05	5810-046-0700	0.130 ppm
2019-07-05	5810-050-0653	0.140 ppm
2019-07-05	5810-054-0755	0.150 ppm
2019-07-05	5810-074-0715	0.170 ppm
2019-07-09	5810-016-0951	0.160 ppm
2019-07-09	5810-019-0842	0.160 ppm
2019-07-09	5810-076-0700	0.160 ppm
2019-07-10	5810-012-0724	0.140 ppm
2019-07-10	5810-031-0655	0.160 ppm
2019-07-11	5810-018-0740	0.120 ppm
2019-07-11	5810-049-0950	0.120 ppm
2019-07-11	5810-077-0745	0.140 ppm
2019-07-12	5810-025-1020	0.180 ppm
2019-07-12	5810-048-0910	0.120 ppm
2019-07-16	5810-032-0925	0.140 ppm
2019-07-16	5810-033-0905	0.120 ppm
2019-07-16	5810-068-0830	0.170 ppm
2019-07-17	5810-034-0935	0.110 ppm
2019-07-17	5810-052-0710	0.110 ppm
2019-07-17	5810-082-0730	0.120 ppm
2019-07-18	5810-036-0820	0.140 ppm
2019-07-18	5810-072-0945	0.110 ppm
2019-07-19	5810-026-0825	0.170 ppm
2019-07-22	5810-005-0800	0.1000 ppm
2019-07-26	5810-020-0832	0.1000 ppm
2019-08-21	5810-067-0920	ND