Fluoride
California Water Service (CWS) - Bakersfield
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 | 0.0913 ppm | 16 | 11 | ND - 0.340 ppm |
| 2015 | 0.131 ppm | 22 | 22 | 0.0570 ppm - 0.280 ppm |
| 2016 | 0.103 ppm | 24 | 24 | 0.0540 ppm - 0.250 ppm |
| 2017 | 0.0798 ppm | 16 | 14 | ND - 0.140 ppm |
| 2018 | 0.119 ppm | 23 | 23 | 0.0640 ppm - 0.200 ppm |
| 2019 | 0.113 ppm | 21 | 21 | 0.0500 ppm - 0.230 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 |
|---|---|---|
| 2014-01-06 | 5810-026-1415 | 0.110 ppm |
| 2014-01-14 | 5810-002-1008 | ND |
| 2014-02-04 | 5810-009-0931 | ND |
| 2014-03-04 | 5810-253-0810 | 0.340 ppm |
| 2014-06-05 | 5810-005-1016 | ND |
| 2014-06-25 | 5810-018-1018 | ND |
| 2014-06-25 | 5810-020-0934 | ND |
| 2014-06-30 | 5810-021-1025 | 0.130 ppm |
| 2014-07-07 | 5806-011-1500 | 0.130 ppm |
| 2014-07-10 | 5806-031-1345 | 0.140 ppm |
| 2014-08-06 | 5806-024-1420 | 0.130 ppm |
| 2014-08-13 | 5806-015-1120 | 0.110 ppm |
| 2014-10-08 | 5806-050-1013 | 0.0720 ppm |
| 2014-10-09 | 5806-004-1326 | 0.0780 ppm |
| 2014-10-20 | 5806-006-1125 | 0.0900 ppm |
| 2014-12-16 | 5810-003-2240 | 0.130 ppm |
| 2015-03-04 | 5806-051-1130 | 0.110 ppm |
| 2015-03-04 | 5806-072-1215 | 0.140 ppm |
| 2015-03-19 | 5806-253-0735 | 0.280 ppm |
| 2015-04-20 | 5806-053-1307 | 0.120 ppm |
| 2015-04-21 | 5806-038-1450 | 0.0850 ppm |
| 2015-05-11 | 5806-096-1025 | 0.150 ppm |
| 2015-05-11 | 5806-105-1331 | 0.110 ppm |
| 2015-05-11 | 5806-156-0938 | 0.120 ppm |
| 2015-07-08 | 5806-059-1410 | 0.160 ppm |
| 2015-07-08 | 5806-068-1132 | 0.180 ppm |
| 2015-08-05 | 5806-099-1400 | 0.130 ppm |
| 2015-08-10 | 5806-098-1035 | 0.0570 ppm |
| 2015-08-13 | 5806-160-0934 | 0.120 ppm |
| 2015-09-10 | 5806-092-1437 | 0.0740 ppm |
| 2015-10-05 | 5806-079-1335 | 0.110 ppm |
| 2015-10-05 | 5806-091-1205 | 0.110 ppm |
| 2015-10-06 | 5806-058-1050 | 0.150 ppm |
| 2015-10-27 | 5806-056-1205 | 0.0860 ppm |
| 2015-12-09 | 5806-106-1300 | 0.120 ppm |
| 2015-12-09 | 5806-163-1203 | 0.170 ppm |
| 2015-12-10 | 5806-094-1315 | 0.140 ppm |
| 2015-12-15 | 5806-108-1015 | 0.160 ppm |
| 2016-01-04 | 5806-106-0905 | 0.0950 ppm |
| 2016-01-04 | 5806-107-0905 | 0.0950 ppm |
| 2016-02-10 | 5806-122-1321 | 0.0900 ppm |
| 2016-03-16 | 5806-253-1025 | 0.250 ppm |
| 2016-05-04 | 5806-124-1235 | 0.110 ppm |
| 2016-05-05 | 5806-118-1350 | 0.0990 ppm |
| 2016-05-20 | 5806-110-1350 | 0.0610 ppm |
| 2016-05-20 | 5806-126-1250 | 0.0930 ppm |
| 2016-06-08 | 5806-148-1230 | 0.110 ppm |
| 2016-06-15 | 5806-131-1045 | 0.120 ppm |
| 2016-06-16 | 5806-055-1025 | 0.0730 ppm |
| 2016-06-17 | 5806-151-1015 | 0.0540 ppm |
| 2016-07-14 | 5806-109-1200 | 0.0680 ppm |
| 2016-08-08 | 5806-149-1240 | 0.1000 ppm |
| 2016-08-08 | 5806-154-0945 | 0.0840 ppm |
| 2016-08-15 | 5806-125-1013 | 0.130 ppm |
| 2016-08-18 | 5806-069-1051 | 0.0990 ppm |
| 2016-08-18 | 5806-150-1153 | 0.120 ppm |
| 2016-09-07 | 5806-119-1120 | 0.0990 ppm |
| 2016-09-08 | 5806-052-1120 | 0.1000 ppm |
| 2016-09-12 | 5806-143-1015 | 0.0980 ppm |
| 2016-09-12 | 5806-146-1055 | 0.110 ppm |
| 2016-09-22 | 5806-117-0930 | 0.0900 ppm |
| 2016-10-11 | 5806-129-1519 | 0.120 ppm |
| 2017-01-10 | 5806-002-1025 | ND |
| 2017-01-19 | 5806-026-0949 | 0.110 ppm |
| 2017-03-14 | 5806-253-0850 | 0.140 ppm |
| 2017-03-23 | 5806-021-0904 | 0.0920 ppm |
| 2017-04-10 | 5806-009-1125 | 0.0670 ppm |
| 2017-04-19 | 5806-004-1145 | 0.0920 ppm |
| 2017-06-12 | 5806-050-1135 | 0.0620 ppm |
| 2017-06-19 | 5806-018-0936 | ND |
| 2017-06-20 | 5806-005-1035 | 0.0500 ppm |
| 2017-06-20 | 5806-015-1019 | 0.0760 ppm |
| 2017-06-26 | 5806-006-0947 | 0.0810 ppm |
| 2017-07-12 | 5806-003-0741 | 0.120 ppm |
| 2017-07-18 | 5806-031-1100 | 0.110 ppm |
| 2017-08-23 | 5806-024-1337 | 0.110 ppm |
| 2017-11-06 | 5806-011-1027 | 0.110 ppm |
| 2017-12-28 | 5806-020-1010 | 0.0570 ppm |
| 2018-03-14 | 5806-051-1140 | 0.0860 ppm |
| 2018-03-14 | 5806-072-1250 | 0.140 ppm |
| 2018-03-22 | 5806-253-0800 | 0.200 ppm |
| 2018-04-16 | 5806-156-1057 | 0.130 ppm |
| 2018-04-17 | 5806-053-1400 | 0.0940 ppm |
| 2018-04-17 | 5806-105-0930 | 0.0680 ppm |
| 2018-04-23 | 5806-094-1107 | 0.120 ppm |
| 2018-04-25 | 5806-096-0930 | 0.130 ppm |
| 2018-04-26 | 5806-038-1145 | 0.0790 ppm |
| 2018-06-15 | 9590-026-0945 | 0.120 ppm |
| 2018-07-11 | 5806-068-1118 | 0.170 ppm |
| 2018-07-11 | 5806-092-1400 | 0.130 ppm |
| 2018-07-11 | 5806-106-1431 | 0.160 ppm |
| 2018-07-12 | 5806-056-1444 | 0.0730 ppm |
| 2018-07-24 | 5806-059-1414 | 0.140 ppm |
| 2018-07-24 | 5806-091-0850 | 0.1000 ppm |
| 2018-08-13 | 5806-099-0950 | 0.0970 ppm |
| 2018-08-21 | 5806-098-0942 | 0.0640 ppm |
| 2018-08-27 | 5806-160-1221 | 0.110 ppm |
| 2018-09-13 | 5806-058-0955 | 0.150 ppm |
| 2018-09-20 | 5806-069-1025 | 0.1000 ppm |
| 2018-10-25 | 5806-058-1144 | 0.140 ppm |
| 2018-11-16 | 5806-048-1128 | 0.140 ppm |
| 2019-01-09 | 5806-107-1109 | 0.110 ppm |
| 2019-02-13 | 5806-122-1021 | 0.0960 ppm |
| 2019-03-26 | 5806-253-1055 | 0.230 ppm |
| 2019-05-14 | 5806-125-0840 | 0.150 ppm |
| 2019-05-14 | 5806-126-0920 | 0.160 ppm |
| 2019-05-15 | 5806-118-1330 | 0.1000 ppm |
| 2019-05-29 | 5806-110-1130 | 0.0740 ppm |
| 2019-05-29 | 5806-124-0930 | 0.130 ppm |
| 2019-06-10 | 5806-148-1100 | 0.110 ppm |
| 2019-06-10 | 5806-151-1059 | 0.0930 ppm |
| 2019-07-18 | 5806-109-0955 | 0.0500 ppm |
| 2019-08-12 | 5806-117-1130 | 0.130 ppm |
| 2019-08-12 | 5806-149-1054 | 0.130 ppm |
| 2019-08-12 | 5806-154-1259 | 0.1000 ppm |
| 2019-09-10 | 5806-146-0836 | 0.110 ppm |
| 2019-09-11 | 5806-143-0920 | 0.0970 ppm |
| 2019-09-24 | 5806-055-1330 | 0.120 ppm |
| 2019-10-16 | 5806-052-1150 | 0.0770 ppm |
| 2019-10-28 | 5806-150-1135 | 0.0950 ppm |
| 2019-11-20 | 5806-108-0835 | 0.110 ppm |
| 2019-12-10 | 5806-119-0845 | 0.110 ppm |