Fluoride

Kennebec Water District

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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438

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	0.672 ppm	138	136	ND - 0.870 ppm
2015	0.705 ppm	145	145	0.600 ppm - 0.860 ppm
2016	0.675 ppm	61	61	0.350 ppm - 0.800 ppm
2017	0.684 ppm	48	48	0.480 ppm - 0.770 ppm
2018	0.659 ppm	33	32	ND - 0.920 ppm
2019	0.729 ppm	13	13	0.640 ppm - 0.870 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
2014-01-07		0.640 ppm
2014-01-07		0.670 ppm
2014-01-07		0.690 ppm
2014-01-16		0.570 ppm
2014-01-16		0.660 ppm
2014-01-16		0.670 ppm
2014-01-21		0.630 ppm
2014-01-21		0.730 ppm
2014-01-21		0.750 ppm
2014-01-27		0.800 ppm
2014-01-27		0.660 ppm
2014-01-27		0.730 ppm
2014-02-03		0.790 ppm
2014-02-03		0.740 ppm
2014-02-03		0.830 ppm
2014-02-10		0.660 ppm
2014-02-10		0.770 ppm
2014-02-10		0.870 ppm
2014-02-18		0.620 ppm
2014-02-18		0.750 ppm
2014-02-18		0.720 ppm
2014-02-25		ND
2014-02-25		0.620 ppm
2014-02-25		ND
2014-03-03		0.120 ppm
2014-03-03		0.610 ppm
2014-03-03		0.580 ppm
2014-03-10		0.0400 ppm
2014-03-10		0.350 ppm
2014-03-10		0.0200 ppm
2014-03-17		0.650 ppm
2014-03-17		0.340 ppm
2014-03-17		0.640 ppm
2014-03-24		0.490 ppm
2014-03-24		0.750 ppm
2014-03-28		0.800 ppm
2014-04-07		0.680 ppm
2014-04-07		0.510 ppm
2014-04-07		0.660 ppm
2014-04-14		0.710 ppm
2014-04-14		0.700 ppm
2014-04-14		0.770 ppm
2014-04-23		0.570 ppm
2014-04-23		0.780 ppm
2014-04-23		0.760 ppm
2014-04-28		0.760 ppm
2014-04-28		0.740 ppm
2014-04-28		0.700 ppm
2014-05-05		0.630 ppm
2014-05-05		0.680 ppm
2014-05-05		0.720 ppm
2014-05-13		0.660 ppm
2014-05-13		0.610 ppm
2014-05-13		0.700 ppm
2014-05-19		0.800 ppm
2014-05-19		0.760 ppm
2014-05-19		0.790 ppm
2014-05-27		0.750 ppm
2014-05-27		0.720 ppm
2014-05-27		0.790 ppm
2014-06-02		0.810 ppm
2014-06-02		0.800 ppm
2014-06-02		0.840 ppm
2014-06-09		0.740 ppm
2014-06-09		0.700 ppm
2014-06-09		0.710 ppm
2014-06-17		0.760 ppm
2014-06-17		0.680 ppm
2014-06-17		0.700 ppm
2014-06-23		0.700 ppm
2014-06-23		0.700 ppm
2014-06-23		0.690 ppm
2014-07-07		0.680 ppm
2014-07-07		0.580 ppm
2014-07-14		0.175 ppm
2014-07-14		0.650 ppm
2014-07-21		0.760 ppm
2014-07-21		0.760 ppm
2014-07-28		0.730 ppm
2014-07-28		0.710 ppm
2014-07-28		0.720 ppm
2014-08-04		0.720 ppm
2014-08-04		0.800 ppm
2014-08-04		0.770 ppm
2014-08-11		0.730 ppm
2014-08-11		0.720 ppm
2014-08-11		0.690 ppm
2014-08-19		0.740 ppm
2014-08-19		0.640 ppm
2014-08-25		0.690 ppm
2014-08-25		0.650 ppm
2014-08-25		0.650 ppm
2014-09-02		0.710 ppm
2014-09-02		0.690 ppm
2014-09-02		0.670 ppm
2014-09-08		0.670 ppm
2014-09-08		0.690 ppm
2014-09-08		0.700 ppm
2014-09-15		0.670 ppm
2014-09-15		0.690 ppm
2014-09-15		0.710 ppm
2014-09-22		0.720 ppm
2014-09-22		0.680 ppm
2014-09-22		0.640 ppm
2014-10-06		0.750 ppm
2014-10-06		0.680 ppm
2014-10-06		0.660 ppm
2014-10-14		0.760 ppm
2014-10-14		0.719 ppm
2014-10-14		0.712 ppm
2014-10-22		0.780 ppm
2014-10-22		0.730 ppm
2014-10-22		0.750 ppm
2014-10-28		0.790 ppm
2014-10-28		0.710 ppm
2014-10-28		0.720 ppm
2014-11-03		0.720 ppm
2014-11-10		0.738 ppm
2014-11-10		0.715 ppm
2014-11-10		0.735 ppm
2014-11-17		0.755 ppm
2014-11-17		0.709 ppm
2014-11-17		0.705 ppm
2014-11-24		0.700 ppm
2014-11-24		0.680 ppm
2014-11-24		0.650 ppm
2014-12-01		0.760 ppm
2014-12-01		0.700 ppm
2014-12-01		0.710 ppm
2014-12-08		0.690 ppm
2014-12-08		0.660 ppm
2014-12-08		0.650 ppm
2014-12-15		0.690 ppm
2014-12-15		0.760 ppm
2014-12-15		0.730 ppm
2014-12-22		0.590 ppm
2014-12-22		0.720 ppm
2014-12-22		0.680 ppm
2015-01-05	F9-10515	0.640 ppm
2015-01-05	F2-10515	0.600 ppm
2015-01-05	F12-10515	0.600 ppm
2015-01-12	F9-11215	0.610 ppm
2015-01-12	F2-11215	0.720 ppm
2015-01-12	F12-11215	0.700 ppm
2015-01-20	F9-12015	0.720 ppm
2015-01-20	F2-12015	0.730 ppm
2015-01-20	F12-12015	0.710 ppm
2015-01-26	F9-12615	0.740 ppm
2015-01-26	F2-12615	0.710 ppm
2015-01-26	F12-12615	0.770 ppm
2015-02-02	F9-20215	0.630 ppm
2015-02-02	F2-20215	0.630 ppm
2015-02-02	F12-20215	0.640 ppm
2015-02-09	F9-20915	0.740 ppm
2015-02-09	F2-20915.	0.700 ppm
2015-02-09	F12-20915	0.720 ppm
2015-02-17	F9-21715	0.760 ppm
2015-02-17	F2-21715	0.830 ppm
2015-02-17	F12-21715	0.760 ppm
2015-02-24	F9-22415	0.720 ppm
2015-02-24	F2-22415	0.730 ppm
2015-02-24	F12-22415	0.730 ppm
2015-03-02	K005605001	0.700 ppm
2015-03-02	F9-30215	0.650 ppm
2015-03-02	F2-30215	0.670 ppm
2015-03-02	F12-30215	0.650 ppm
2015-03-09	F9-30915	0.720 ppm
2015-03-09	F2-30915	0.700 ppm
2015-03-09	F12-30915	0.640 ppm
2015-03-17	F9-31715	0.780 ppm
2015-03-17	F2-31715	0.760 ppm
2015-03-17	F12-31715	0.760 ppm
2015-03-23	F9-32315	0.650 ppm
2015-03-23	F2-32315	0.660 ppm
2015-03-23	F12-32315	0.650 ppm
2015-04-06	F9-40615	0.720 ppm
2015-04-06	F2-40615	0.720 ppm
2015-04-06	F12-40615	0.770 ppm
2015-04-13	F9-41315	0.760 ppm
2015-04-13	F2-41315	0.740 ppm
2015-04-13	F12-41315	0.790 ppm
2015-04-21	F9-42115	0.690 ppm
2015-04-21	F2-42115	0.670 ppm
2015-04-21	F12-42115	0.700 ppm
2015-04-27	F9-42715	0.700 ppm
2015-04-27	F2-42715	0.750 ppm
2015-04-27	F12-42715	0.810 ppm
2015-05-04	F9-50415	0.640 ppm
2015-05-04	F2-50415	0.770 ppm
2015-05-04	F12-50415	0.740 ppm
2015-05-11	F9-51115	0.790 ppm
2015-05-11	F2-51115	0.860 ppm
2015-05-11	F12-51115	0.830 ppm
2015-05-18	F9-51815	0.790 ppm
2015-05-18	F2-51815	0.810 ppm
2015-05-18	F12-51815	0.790 ppm
2015-05-26	F9-52615	0.740 ppm
2015-05-26	F2-52615	0.710 ppm
2015-05-26	F12-52615	0.640 ppm
2015-06-03	F9-60315	0.770 ppm
2015-06-03	F2-60315	0.790 ppm
2015-06-03	F12-60315	0.760 ppm
2015-06-08	F9-60815	0.700 ppm
2015-06-08	F2-60815	0.670 ppm
2015-06-08	F12-60815	0.670 ppm
2015-06-15	F9-61515	0.710 ppm
2015-06-15	F2-61515	0.680 ppm
2015-06-15	F12-61515	0.710 ppm
2015-06-22	F9-62215	0.680 ppm
2015-06-22	F2-62215	0.670 ppm
2015-06-22	F12-62215	0.660 ppm
2015-07-06	F9-70615	0.770 ppm
2015-07-06	F2-70615	0.740 ppm
2015-07-06	F12-70615	0.750 ppm
2015-07-14	F9-71415	0.700 ppm
2015-07-14	F2-71415	0.700 ppm
2015-07-14	F12-71415	0.670 ppm
2015-07-21	F9-72115	0.700 ppm
2015-07-21	F2-72115	0.660 ppm
2015-07-21	F12-72115	0.690 ppm
2015-07-27	F9-72715	0.630 ppm
2015-07-27	F2-72715	0.620 ppm
2015-07-27	F12-72715	0.610 ppm
2015-08-03	F9-80315	0.650 ppm
2015-08-03	F2-80315	0.690 ppm
2015-08-03	F12-80315	0.630 ppm
2015-08-10	F9-81015	0.650 ppm
2015-08-10	F2-81015	0.640 ppm
2015-08-10	F12-81015	0.620 ppm
2015-08-18	F9-81815	0.680 ppm
2015-08-18	F2-81815	0.660 ppm
2015-08-18	F12-81815	0.670 ppm
2015-08-24	F9-82415	0.680 ppm
2015-08-24	F2-82415	0.690 ppm
2015-08-24	F12-82415	0.690 ppm
2015-09-08	F9-90815	0.700 ppm
2015-09-08	F2-90815	0.710 ppm
2015-09-08	F12-90815	0.710 ppm
2015-09-14	F9-91415	0.730 ppm
2015-09-14	F2-91415	0.730 ppm
2015-09-14	F12-91415	0.690 ppm
2015-09-21	F9-92115	0.720 ppm
2015-09-21	F2-92115	0.690 ppm
2015-09-21	F12-92115	0.690 ppm
2015-09-28	F9-92815	0.710 ppm
2015-09-28	F2-92815	0.750 ppm
2015-09-28	F12-92815	0.720 ppm
2015-10-05	F9-100515	0.750 ppm
2015-10-05	F2-100515	0.750 ppm
2015-10-05	F12-100515	0.740 ppm
2015-10-14	F9-101415	0.710 ppm
2015-10-14	F2-101415	0.750 ppm
2015-10-14	F12-101415	0.690 ppm
2015-10-19	F9-101915	0.760 ppm
2015-10-19	F2-101915	0.760 ppm
2015-10-19	F12-101915	0.720 ppm
2015-10-26	F9-102615	0.740 ppm
2015-10-26	F2-102615	0.730 ppm
2015-10-26	F12-102615	0.780 ppm
2015-11-03	F9-110315	0.720 ppm
2015-11-03	F2-110315	0.690 ppm
2015-11-03	F12-110315	0.760 ppm
2015-11-09	F9-110915	0.750 ppm
2015-11-09	F2-110915	0.770 ppm
2015-11-09	F12-110915	0.750 ppm
2015-11-16	F9-111615	0.710 ppm
2015-11-16	F2-111615	0.690 ppm
2015-11-16	F12-111615	0.700 ppm
2015-11-23	F9-112315	0.690 ppm
2015-11-23	F2-112315	0.680 ppm
2015-11-23	F12-112315	0.700 ppm
2015-12-08	F9-120815	0.680 ppm
2015-12-08	F2-120815	0.690 ppm
2015-12-08	F12-120815	0.690 ppm
2015-12-14	F9-121415	0.610 ppm
2015-12-14	F2-121415	0.640 ppm
2015-12-14	F12-121415	0.630 ppm
2015-12-22	F9-122215	0.650 ppm
2015-12-22	F2-122215	0.650 ppm
2015-12-22	F12-122215	0.660 ppm
2015-12-28	F9-122815	0.630 ppm
2015-12-28	F2-122815	0.640 ppm
2015-12-28	F12-122815	0.640 ppm
2016-01-05	F9-10516	0.590 ppm
2016-01-05	F2-10516	0.720 ppm
2016-01-05	F12-10516	0.590 ppm
2016-01-11	F9-11116	0.600 ppm
2016-01-11	F2-11116	0.730 ppm
2016-01-11	F12-11116	0.650 ppm
2016-01-19	F9-11916	0.790 ppm
2016-01-19	F2-11916	0.800 ppm
2016-01-19	F12-11916	0.790 ppm
2016-01-26	F9-12616	0.750 ppm
2016-01-26	F2-12616	0.690 ppm
2016-01-26	F12-12616	0.720 ppm
2016-02-01	F9-20116	0.740 ppm
2016-02-01	F2-20116	0.660 ppm
2016-02-01	F12-20116	0.730 ppm
2016-02-08	F9-20816	0.650 ppm
2016-02-08	F2-20816	0.670 ppm
2016-02-08	F12-20816	0.640 ppm
2016-02-17	F9-21716	0.670 ppm
2016-02-17	F2-21716	0.650 ppm
2016-02-17	F12-21716	0.670 ppm
2016-02-22	F9-22216	0.670 ppm
2016-02-22	F2-22216	0.690 ppm
2016-02-22	F12-22216	0.680 ppm
2016-03-08	F5-30816	0.720 ppm
2016-03-14	F5-31416	0.690 ppm
2016-03-22	F5-32216	0.750 ppm
2016-03-28	F5-32816	0.720 ppm
2016-04-04	F5-40416	0.670 ppm
2016-04-05	L008569001	0.700 ppm
2016-04-11	F5-41116	0.700 ppm
2016-04-19	F5-41916	0.680 ppm
2016-04-25	F5-42516	0.800 ppm
2016-05-02	F5--20160502	0.680 ppm
2016-05-09	F5-20160509	0.700 ppm
2016-05-16	F5-20160516	0.690 ppm
2016-05-23	F5-20160523	0.640 ppm
2016-06-06	F5-20160606	0.660 ppm
2016-06-13	F5-20160613	0.640 ppm
2016-07-18	F5-20160718	0.350 ppm
2016-07-26	F5-20160726	0.470 ppm
2016-08-01	F5-20160801	0.550 ppm
2016-08-15	F5-20160815	0.600 ppm
2016-08-23	F5-20160823	0.680 ppm
2016-08-29	F5-20160829	0.660 ppm
2016-09-06	F5-20160906	0.690 ppm
2016-09-12	F5-20160912	0.680 ppm
2016-09-19	F5-20160919	0.680 ppm
2016-09-27	F5-20160927	0.690 ppm
2016-10-03	F5-20161003	0.720 ppm
2016-10-11	F5-20161011	0.640 ppm
2016-10-17	F5-20161017	0.680 ppm
2016-10-24	F5-20161024	0.670 ppm
2016-11-08	F5-20161108	0.660 ppm
2016-11-15	F5-20161115	0.700 ppm
2016-11-21	F5-20161121	0.680 ppm
2016-11-28	F5-20161128	0.710 ppm
2016-12-05	F5-20161205	0.680 ppm
2016-12-13	F5-20161213	0.660 ppm
2016-12-19	F5-20161219	0.650 ppm
2016-12-27	F5-20161227	0.690 ppm
2017-01-03	F5-20170103	0.660 ppm
2017-01-09	F5-20170109	0.680 ppm
2017-01-17	F5-20170117	0.650 ppm
2017-01-23	F5-20170123	0.630 ppm
2017-02-07	F5-20170207	0.670 ppm
2017-02-14	F5-20170214	0.740 ppm
2017-02-21	F5-20170221	0.740 ppm
2017-02-27	F5-20170227	0.710 ppm
2017-03-06	F5-20170306	0.720 ppm
2017-03-13	F5-20170313	0.700 ppm
2017-03-21	F5-20170321	0.730 ppm
2017-03-27	F5-20170327	0.730 ppm
2017-04-03	F5-20170403	0.690 ppm
2017-04-10	1701435-01	0.700 ppm
2017-04-11	F5-20170411	0.720 ppm
2017-04-18	F5-20170418	0.720 ppm
2017-04-25	F5-20170425	0.680 ppm
2017-05-02	F5-20170502	0.680 ppm
2017-05-08	F5-20170508	0.750 ppm
2017-05-16	F5-20170516	0.700 ppm
2017-05-22	F5-20170522	0.570 ppm
2017-06-05	F5-20170605	0.710 ppm
2017-06-12	F5-20170612	0.710 ppm
2017-06-19	F5-20170619	0.710 ppm
2017-06-26	F5-20170626	0.670 ppm
2017-07-05	F5-20170705	0.700 ppm
2017-07-10	F5-20170710	0.660 ppm
2017-07-24	F5-20170724	0.720 ppm
2017-07-31	F5-20170731	0.690 ppm
2017-08-10	F5-20170810	0.770 ppm
2017-08-15	F5-20170815	0.690 ppm
2017-08-21	F5-20170821	0.730 ppm
2017-08-28	F5-20170828	0.700 ppm
2017-09-07	F5-20170907	0.710 ppm
2017-09-12	F5-20170912	0.710 ppm
2017-09-18	F5-20170918	0.740 ppm
2017-09-25	F5-20170925	0.680 ppm
2017-10-03	F5-20171003	0.750 ppm
2017-10-10	F5-20171010	0.700 ppm
2017-10-16	F5-20171016	0.710 ppm
2017-10-23	F5-20171023	0.710 ppm
2017-11-13	F5-20171113	0.480 ppm
2017-11-20	F5-20171120	0.490 ppm
2017-11-27	F5-20171127	0.560 ppm
2017-12-04	F5-20171204	0.640 ppm
2017-12-11	F5-20171211	0.620 ppm
2017-12-18	F5-20171218	0.630 ppm
2017-12-27	F5-20171227	0.690 ppm
2018-01-02	F5-20180102	0.670 ppm
2018-01-08	F5-20180108	0.690 ppm
2018-01-16	F5-20180116	0.670 ppm
2018-01-22	F5-20180122	0.700 ppm
2018-02-05	F5-20180205	0.710 ppm
2018-02-12	F5-20180212	0.720 ppm
2018-02-21	F5-20180221	0.680 ppm
2018-02-26	F5-20180226	0.690 ppm
2018-03-05	F5-20180305	0.660 ppm
2018-03-12	F5-20180312	0.670 ppm
2018-03-20	F5-20180320	0.670 ppm
2018-03-27	F5-20180327	0.680 ppm
2018-04-03	F5-20180403	0.720 ppm
2018-04-04	401800699C	0.760 ppm
2018-04-09	F5-20180409	0.710 ppm
2018-04-17	F5-20180417	0.690 ppm
2018-04-23	F5-20180423	0.680 ppm
2018-05-07	F5-20180507	0.690 ppm
2018-05-14	F5-20180514	0.660 ppm
2018-05-21	F5-20180521	0.700 ppm
2018-05-29	F5-20180529	0.700 ppm
2018-06-05	F5-20180605	0.700 ppm
2018-06-12	F5-20180612	ND
2018-06-19	F5-20180619	0.430 ppm
2018-06-20	301805728C	0.540 ppm
2018-06-22	301805892C	0.550 ppm
2018-06-25	F5-20180625	0.480 ppm
2018-07-11	301806806C	0.740 ppm
2018-08-07	301809202C	0.820 ppm
2018-09-10	301809868C	0.600 ppm
2018-10-04	301811031C	0.720 ppm
2018-11-06	301812224C	0.730 ppm
2018-12-04	301813096C	0.920 ppm
2019-01-09	301900191C	0.700 ppm
2019-02-06	301900817C	0.870 ppm
2019-03-05	301901457C	0.680 ppm
2019-04-04	301902437C	0.750 ppm
2019-05-06	301903590C	0.750 ppm
2019-05-15	401901291	0.760 ppm
2019-06-07	301905152C	0.730 ppm
2019-07-11	301906830C	0.650 ppm
2019-08-07	301908240C	0.740 ppm
2019-09-17	301910203C	0.640 ppm
2019-10-03	301910954C	0.740 ppm
2019-11-07	301912293C	0.760 ppm
2019-12-05	451900109C	0.710 ppm