Fluoride
San Gabriel Valley Water Company- El Monte
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 | 0.345 ppm | 25 | 25 | 0.210 ppm - 0.680 ppm |
| 2015 | 0.412 ppm | 16 | 16 | 0.240 ppm - 0.790 ppm |
| 2016 | 0.342 ppm | 24 | 24 | 0.130 ppm - 0.580 ppm |
| 2017 | 0.342 ppm | 23 | 23 | 0.160 ppm - 0.700 ppm |
| 2018 | 0.431 ppm | 16 | 16 | 0.240 ppm - 0.910 ppm |
| 2019 | 0.377 ppm | 22 | 22 | 0.230 ppm - 0.660 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 |
|---|---|---|
| 2014-03-31 | 9588-029-0845 | 0.280 ppm |
| 2014-04-10 | 9588-023-0950 | 0.230 ppm |
| 2014-04-10 | 9588-077-1005 | 0.330 ppm |
| 2014-05-06 | 9588-011-0935 | 0.590 ppm |
| 2014-06-18 | 9588-003-0815 | 0.270 ppm |
| 2014-08-13 | 9588-001-1035 | 0.260 ppm |
| 2014-08-13 | 9588-006-1020 | 0.610 ppm |
| 2014-08-14 | 9588-018-1200 | 0.400 ppm |
| 2014-08-14 | 9588-026-1000 | 0.260 ppm |
| 2014-08-14 | 9588-027-0915 | 0.390 ppm |
| 2014-08-14 | 9588-029-1210 | 0.360 ppm |
| 2014-08-27 | 9588-009-0905 | 0.680 ppm |
| 2014-08-27 | 9588-112-0725 | 0.240 ppm |
| 2014-08-27 | 9588-113-0735 | 0.310 ppm |
| 2014-08-27 | 9588-114-0750 | 0.240 ppm |
| 2014-08-27 | 9588-115-0815 | 0.360 ppm |
| 2014-09-15 | 9588-001-0905 | 0.210 ppm |
| 2014-09-15 | 9588-013-0945 | 0.350 ppm |
| 2014-09-15 | 9588-015-1000 | 0.290 ppm |
| 2014-09-15 | 9588-033-1220 | 0.300 ppm |
| 2014-09-15 | 9588-116-1305 | 0.270 ppm |
| 2014-09-23 | 9588-005-1430 | 0.560 ppm |
| 2014-09-24 | 9588-117-1135 | 0.310 ppm |
| 2014-11-13 | 9588-070-1045 | 0.260 ppm |
| 2014-11-26 | 9588-070-0805 | 0.260 ppm |
| 2015-02-10 | 9588-114-0855 | 0.280 ppm |
| 2015-02-10 | 9588-115-0845 | 0.400 ppm |
| 2015-05-12 | 9588-030-1020 | 0.250 ppm |
| 2015-06-17 | 9588-018-1315 | 0.390 ppm |
| 2015-06-17 | 9588-030-1215 | 0.270 ppm |
| 2015-08-11 | 9588-002-1215 | 0.260 ppm |
| 2015-08-11 | 9588-009-1025 | 0.640 ppm |
| 2015-08-11 | 9588-010-0940 | 0.580 ppm |
| 2015-08-11 | 9588-013-1110 | 0.330 ppm |
| 2015-08-11 | 9588-015-1120 | 0.320 ppm |
| 2015-08-11 | 9588-076-1255 | 0.460 ppm |
| 2015-11-13 | 9588-003-1040 | 0.240 ppm |
| 2015-11-13 | 9588-036-0900 | 0.690 ppm |
| 2015-12-03 | 9588-014-1115 | 0.330 ppm |
| 2015-12-30 | 9588-014-0950 | 0.360 ppm |
| 2015-12-30 | 9588-036-0850 | 0.790 ppm |
| 2016-02-10 | 9588-116-1125 | 0.260 ppm |
| 2016-02-10 | 9588-117-1130 | 0.230 ppm |
| 2016-05-05 | 9588-112-1020 | 0.170 ppm |
| 2016-05-05 | 9588-113-1005 | 0.270 ppm |
| 2016-08-10 | 9588-002-1150 | 0.210 ppm |
| 2016-08-10 | 9588-005-1045 | 0.490 ppm |
| 2016-08-10 | 9588-006-1110 | 0.580 ppm |
| 2016-08-10 | 9588-010-0755 | 0.540 ppm |
| 2016-08-10 | 9588-011-0810 | 0.560 ppm |
| 2016-08-10 | 9588-012-0945 | 0.410 ppm |
| 2016-08-10 | 9588-076-1130 | 0.450 ppm |
| 2016-08-15 | 9588-069-1010 | 0.280 ppm |
| 2016-08-17 | 9588-023-1145 | 0.160 ppm |
| 2016-08-17 | 9588-026-1150 | 0.130 ppm |
| 2016-08-17 | 9588-027-1200 | 0.270 ppm |
| 2016-08-17 | 9588-033-0940 | 0.270 ppm |
| 2016-08-17 | 9588-069-1200 | 0.300 ppm |
| 2016-08-17 | 9588-077-1125 | 0.260 ppm |
| 2016-08-18 | 9588-012-1025 | 0.320 ppm |
| 2016-10-19 | 9588-066-0935 | 0.530 ppm |
| 2016-10-21 | 9588-038-1115 | 0.300 ppm |
| 2016-10-21 | 9588-044-0830 | 0.300 ppm |
| 2016-10-21 | 9588-068-0900 | 0.470 ppm |
| 2016-11-10 | 9588-066-1015 | 0.450 ppm |
| 2017-04-25 | 9588-023-0950 | 0.260 ppm |
| 2017-04-25 | 9588-077-1000 | 0.340 ppm |
| 2017-05-11 | 9588-011-1010 | 0.700 ppm |
| 2017-06-22 | 9588-003-1150 | 0.260 ppm |
| 2017-07-06 | 9588-224-0950 | 0.330 ppm |
| 2017-08-16 | 9588-018-0945 | 0.370 ppm |
| 2017-08-16 | 9588-027-1040 | 0.320 ppm |
| 2017-08-17 | 9588-001-1145 | 0.160 ppm |
| 2017-08-17 | 9588-005-1210 | 0.510 ppm |
| 2017-08-17 | 9588-006-1215 | 0.640 ppm |
| 2017-09-12 | 9588-112-1003 | 0.220 ppm |
| 2017-09-12 | 9588-113-0955 | 0.310 ppm |
| 2017-09-12 | 9588-114-1022 | 0.250 ppm |
| 2017-09-12 | 9588-115-1015 | 0.350 ppm |
| 2017-09-14 | 9588-001-0830 | 0.180 ppm |
| 2017-09-14 | 9588-009-0800 | 0.640 ppm |
| 2017-09-14 | 9588-013-0900 | 0.310 ppm |
| 2017-09-14 | 9588-015-0930 | 0.320 ppm |
| 2017-09-14 | 9588-033-1150 | 0.280 ppm |
| 2017-09-14 | 9588-116-1255 | 0.250 ppm |
| 2017-09-14 | 9588-117-1325 | 0.310 ppm |
| 2017-11-07 | 9588-070-1140 | 0.290 ppm |
| 2017-11-08 | 9588-070-1025 | 0.270 ppm |
| 2018-02-06 | 9588-114-0935 | 0.290 ppm |
| 2018-02-06 | 9588-115-0920 | 0.400 ppm |
| 2018-05-09 | 9588-030-1105 | 0.300 ppm |
| 2018-06-12 | 9588-030-0815 | 0.270 ppm |
| 2018-06-13 | 9588-018-1045 | 0.360 ppm |
| 2018-08-22 | 9588-009-0915 | 0.680 ppm |
| 2018-08-22 | 9588-010-0935 | 0.690 ppm |
| 2018-08-22 | 9588-013-1140 | 0.340 ppm |
| 2018-08-22 | 9588-015-1150 | 0.310 ppm |
| 2018-08-22 | 9588-076-1030 | 0.500 ppm |
| 2018-10-04 | 9588-224-0830 | 0.310 ppm |
| 2018-11-08 | 9588-003-1205 | 0.240 ppm |
| 2018-11-08 | 9588-014-1325 | 0.250 ppm |
| 2018-11-08 | 9588-036-0850 | 0.760 ppm |
| 2018-12-11 | 9588-014-1130 | 0.280 ppm |
| 2018-12-12 | 9588-036-0940 | 0.910 ppm |
| 2019-02-14 | 9588-116-1120 | 0.300 ppm |
| 2019-02-14 | 9588-117-1140 | 0.290 ppm |
| 2019-05-14 | 9588-112-0845 | 0.240 ppm |
| 2019-05-14 | 9588-113-0835 | 0.340 ppm |
| 2019-08-12 | 9588-023-0845 | 0.230 ppm |
| 2019-08-12 | 9588-033-1040 | 0.320 ppm |
| 2019-08-12 | 9588-069-0930 | 0.360 ppm |
| 2019-08-12 | 9588-069-1035 | 0.370 ppm |
| 2019-08-12 | 9588-077-0855 | 0.310 ppm |
| 2019-08-13 | 9588-005-0711 | 0.530 ppm |
| 2019-08-13 | 9588-006-0735 | 0.660 ppm |
| 2019-08-13 | 9588-012-0955 | 0.410 ppm |
| 2019-08-13 | 9588-076-0659 | 0.510 ppm |
| 2019-08-14 | 9588-010-0645 | 0.590 ppm |
| 2019-08-14 | 9588-011-0725 | 0.630 ppm |
| 2019-08-14 | 9588-012-0820 | 0.400 ppm |
| 2019-10-23 | 9588-066-1140 | 0.400 ppm |
| 2019-11-18 | 9588-066-1120 | 0.410 ppm |
| 2019-11-21 | 9588-038-1410 | 0.260 ppm |
| 2019-11-21 | 9588-044-1445 | 0.260 ppm |
| 2019-11-21 | 9588-068-1505 | 0.230 ppm |
| 2019-11-21 | 9588-071-1500 | 0.250 ppm |