Fluoride
Cucamonga Valley 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.
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 | 0.272 ppm | 31 | 31 | 0.120 ppm - 0.520 ppm |
| 2015 | 0.217 ppm | 7 | 7 | 0.150 ppm - 0.320 ppm |
| 2016 | 0.268 ppm | 5 | 5 | 0.120 ppm - 0.390 ppm |
| 2017 | 0.189 ppm | 24 | 21 | ND - 0.430 ppm |
| 2018 | 0.163 ppm | 29 | 25 | ND - 0.410 ppm |
| 2019 | 0.110 ppm | 4 | 2 | ND - 0.260 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 |
|---|---|---|
| 2014-02-27 | 3761-038-1255 | 0.190 ppm |
| 2014-05-29 | 3761-033-0940 | 0.170 ppm |
| 2014-06-05 | 3761-027-1045 | 0.250 ppm |
| 2014-06-18 | 3761-051-1138 | 0.170 ppm |
| 2014-06-19 | 3761-054-0940 | 0.200 ppm |
| 2014-06-19 | 3761-053-0925 | 0.250 ppm |
| 2014-06-19 | 3761-052-0930 | 0.220 ppm |
| 2014-06-19 | 3761-050-1035 | 0.240 ppm |
| 2014-06-26 | 3761-029-1052 | 0.520 ppm |
| 2014-06-26 | 3761-010-1103 | 0.470 ppm |
| 2014-06-26 | 3761-035-1022 | 0.280 ppm |
| 2014-06-26 | 3761-035-1007 | 0.390 ppm |
| 2014-06-26 | 3761-034-1042 | 0.500 ppm |
| 2014-06-26 | 3761-008-1015 | 0.420 ppm |
| 2014-07-10 | 3761-002-1103 | 0.210 ppm |
| 2014-07-10 | 3761-025-1042 | 0.290 ppm |
| 2014-07-10 | 3761-037-1007 | 0.210 ppm |
| 2014-07-10 | 3761-004-1022 | 0.270 ppm |
| 2014-07-10 | 3761-042-1015 | 0.340 ppm |
| 2014-07-10 | 3761-003-1052 | 0.250 ppm |
| 2014-08-05 | 3761-055-1150 | 0.240 ppm |
| 2014-08-14 | 3761-016-1105 | 0.120 ppm |
| 2014-08-14 | 3761-022-0842 | 0.250 ppm |
| 2014-08-14 | 3761-001-0917 | 0.370 ppm |
| 2014-08-18 | 3761-033-1050 | 0.200 ppm |
| 2014-08-21 | 3761-024-0940 | 0.190 ppm |
| 2014-08-21 | 3761-023-0930 | 0.150 ppm |
| 2014-09-04 | 3761-027-1010 | 0.360 ppm |
| 2014-10-16 | 3761-039-1050 | 0.280 ppm |
| 2014-11-20 | 3761-033-1145 | 0.130 ppm |
| 2014-12-09 | 3761-027-1040 | 0.290 ppm |
| 2015-03-05 | 3761-027-0855 | 0.280 ppm |
| 2015-05-13 | 3761-055-1050 | 0.160 ppm |
| 2015-06-11 | 3761-022-1035 | 0.210 ppm |
| 2015-06-11 | 3761-001-1020 | 0.320 ppm |
| 2015-07-09 | 3761-017-1100 | 0.200 ppm |
| 2015-08-20 | 3761-055-0925 | 0.200 ppm |
| 2015-11-23 | 3761-055-0900 | 0.150 ppm |
| 2016-02-11 | 3761-055-1040 | 0.190 ppm |
| 2016-07-21 | 3761-001-0930 | 0.380 ppm |
| 2016-07-21 | 3761-022-0955 | 0.260 ppm |
| 2016-07-21 | 3761-017-1120 | 0.120 ppm |
| 2016-11-23 | 3761-035-1440 | 0.390 ppm |
| 2017-06-02 | 3761-027-0918 | 0.300 ppm |
| 2017-06-14 | 3761-035-0930 | 0.280 ppm |
| 2017-06-14 | 3761-039-0959 | 0.220 ppm |
| 2017-06-14 | 3761-038-1026 | 0.150 ppm |
| 2017-06-15 | 3761-034-0910 | 0.430 ppm |
| 2017-06-15 | 3761-033-1047 | 0.1000 ppm |
| 2017-06-15 | 3761-008-0931 | 0.260 ppm |
| 2017-06-19 | 3761-042-0859 | 0.170 ppm |
| 2017-06-19 | 3761-053-0908 | 0.140 ppm |
| 2017-06-22 | 3761-003-0806 | 0.120 ppm |
| 2017-06-22 | 3761-025-0818 | 0.150 ppm |
| 2017-06-22 | 3761-052-0913 | 0.140 ppm |
| 2017-06-22 | 3761-053-0902 | 0.160 ppm |
| 2017-06-26 | 3761-002-0929 | ND |
| 2017-06-26 | 3761-054-1041 | ND |
| 2017-06-28 | 3761-050-0744 | 0.240 ppm |
| 2017-06-28 | 3761-051-0735 | 0.270 ppm |
| 2017-07-03 | 3761-055-1041 | 0.110 ppm |
| 2017-07-12 | 3761-017-1408 | ND |
| 2017-07-13 | 3761-022-0928 | 0.180 ppm |
| 2017-07-13 | 3761-001-0733 | 0.260 ppm |
| 2017-07-13 | 3761-010-1305 | 0.350 ppm |
| 2017-07-13 | 3761-029-1319 | 0.350 ppm |
| 2017-07-17 | 3761-004-1231 | 0.160 ppm |
| 2018-03-14 | 3761-023-1149 | ND |
| 2018-03-14 | 3761-016-1008 | ND |
| 2018-03-28 | 3761-024-0931 | 0.120 ppm |
| 2018-06-20 | 9588-029-1228 | 0.330 ppm |
| 2018-06-20 | 9588-027-1105 | 0.210 ppm |
| 2018-06-20 | 9588-038-1138 | 0.160 ppm |
| 2018-06-20 | 9588-008-1044 | 0.270 ppm |
| 2018-06-20 | 9588-034-1200 | 0.400 ppm |
| 2018-06-21 | 9588-003-0848 | 0.130 ppm |
| 2018-06-21 | 9588-051-0815 | 0.160 ppm |
| 2018-06-21 | 9588-037-0914 | 0.140 ppm |
| 2018-06-21 | 9588-050-1244 | 0.150 ppm |
| 2018-06-21 | 9588-025-0832 | 0.150 ppm |
| 2018-06-25 | 9588-035-1127 | 0.410 ppm |
| 2018-06-25 | 9588-004-0941 | 0.160 ppm |
| 2018-06-26 | 9588-054-1035 | 0.120 ppm |
| 2018-06-26 | 9588-052-0925 | 0.140 ppm |
| 2018-06-26 | 9588-053-1000 | 0.160 ppm |
| 2018-06-27 | 9588-033-1020 | 0.1000 ppm |
| 2018-06-27 | 9588-055-1140 | 0.120 ppm |
| 2018-07-03 | 9588-010-0917 | 0.350 ppm |
| 2018-07-11 | 9588-042-0950 | 0.180 ppm |
| 2018-07-11 | 9588-002-1000 | 0.110 ppm |
| 2018-07-12 | 9588-017-1214 | ND |
| 2018-07-18 | 9588-022-1010 | 0.170 ppm |
| 2018-07-18 | 9588-001-0950 | 0.270 ppm |
| 2018-07-26 | 9588-016-0846 | ND |
| 2018-07-26 | 9588-023-0912 | 0.1000 ppm |
| 2018-07-26 | 9588-024-0904 | 0.110 ppm |
| 2019-07-01 | 9588-017-0945 | ND |
| 2019-07-24 | 9588-017-1115 | ND |
| 2019-07-26 | 9588-022-0915 | 0.180 ppm |
| 2019-07-26 | 9588-001-0900 | 0.260 ppm |