Know Your Environment. Protect Your Health.

Fluoride

Hillview Water Company-oakhurst/sierra Lakes

Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems to prevent cavities and support oral health in people.

In 2015, the Department of Health and Human Services updated its recommendation of an optimal level of 0.7 parts per million, or ppm, added to drinking water based on the health benefits of tooth decay prevention. Studies have shown that fluoride added to community water systems at this level reduces dental cavities, especially in children.

And studies have conclusively shown that fluoride in toothpaste and mouthwash can also provide these benefits. Read More.

Health Concerns

Although the HHS-recommended level of 0.7 ppm can help promote oral health in children and adults, this level is likely too high for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water.

And fluoride in water at higher levels can be detrimental for everyone, especially children.

Long-term ingestion of higher levels of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth in children.

A 2024 authoritative assessment by the National Toxicology Program found that higher levels of fluoride exposure, such as drinking water containing more than 1.5 ppm of fluoride, are associated with lower IQ in children. The conclusion was based on studies in human populations outside of the U.S.

Affecting systems with naturally occurring fluoride, 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 fracture. But these effects may occur at lower levels of exposure, raising concerns that the current limit may not adequately protect public health.

 

58

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.324 ppm770.220 ppm - 0.550 ppm
20190.265 ppm220.170 ppm - 0.360 ppm
20200.363 ppm2220ND - 0.730 ppm
20210.389 ppm12120.220 ppm - 0.540 ppm
2022N/A00N/A
20230.365 ppm1514ND - 0.820 ppm

ppm = parts per million

State, National, and Health Guidelines for Drinking Water

EPA Maximum Contaminant
Level (MCL): 4 ppm

ppm = parts per million

All test results

Date Lab ID Result
2018-04-30CA2010007_047_047-2018043014100.300 ppm
2018-04-30CA2010007_046_046-2018043014100.240 ppm
2018-04-30CA2010007_048_048-2018043014320.360 ppm
2018-04-30CA2010007_024_024-2018043014450.360 ppm
2018-07-25CA2010007_009_009-2018072510000.550 ppm
2018-07-25CA2010007_010_010-2018072510250.240 ppm
2018-09-19CA2010007_001_001-2018091909110.220 ppm
2019-12-11CA2010007_039_039-2019121108500.360 ppm
2019-12-11CA2010007_041_041-2019121109050.170 ppm
2020-03-09CA2010007_032_032-2020030909450.460 ppm
2020-03-09CA2010007_033_033-2020030910000.540 ppm
2020-03-09CA2010007_017_017-2020030910500.110 ppm
2020-03-09CA2010007_030_030-2020030909140.730 ppm
2020-03-09CA2010007_031_031-2020030909300.730 ppm
2020-03-23CA2010007_034_034-2020032310150.420 ppm
2020-05-04CA2010007_002_002-202005041011ND
2020-05-04CA2010007_003_003-2020050410000.180 ppm
2020-05-04CA2010007_028_028-2020050410250.120 ppm
2020-05-05CA2010007_007_007-2020050508140.460 ppm
2020-08-20CA2010007_034_034-2020082011120.470 ppm
2020-08-20CA2010007_007_007-2020082011020.420 ppm
2020-08-20CA2010007_033_033-2020082011550.520 ppm
2020-08-20CA2010007_041_041-2020082012150.1000 ppm
2020-08-20CA2010007_003_003-2020082013540.170 ppm
2020-08-20CA2010007_031_031-2020082011410.660 ppm
2020-08-20CA2010007_002_002-2020082013430.150 ppm
2020-08-20CA2010007_028_028-2020082011320.110 ppm
2020-08-20CA2010007_032_032-2020082011480.480 ppm
2020-08-20CA2010007_017_017-202008200820ND
2020-08-20CA2010007_030_030-2020082011270.530 ppm
2020-08-20CA2010007_039_039-2020082012300.630 ppm
2021-02-17CA2010007_040_040-2021021711050.380 ppm
2021-08-11CA2010007_048_048-2021081109080.540 ppm
2021-08-16CA2010007_010_010-2021081609080.520 ppm
2021-08-16CA2010007_047_047-2021081609080.340 ppm
2021-08-16CA2010007_001_001-2021081608080.220 ppm
2021-08-16CA2010007_046_046-2021081609080.380 ppm
2021-08-16CA2010007_024_024-2021081609080.250 ppm
2021-08-16CA2010007_009_009-2021081609080.480 ppm
2021-09-28CA2010007_014_014-2021092808000.260 ppm
2021-09-28CA2010007_051_051-2021092807570.480 ppm
2021-09-28CA2010007_048_048-2021092809020.510 ppm
2021-09-28CA2010007_047_047-2021092808580.310 ppm
2023-06-05CA2010007_033_033-2023060509580.480 ppm
2023-06-05CA2010007_032_032-2023060509510.470 ppm
2023-06-05CA2010007_041_041-2023060510120.150 ppm
2023-06-05CA2010007_040_040-2023060510310.240 ppm
2023-06-05CA2010007_034_034-2023060510150.450 ppm
2023-06-05CA2010007_030_030-2023060509350.550 ppm
2023-06-05CA2010007_039_039-2023060511170.820 ppm
2023-06-05CA2010007_007_007-2023060509150.440 ppm
2023-06-05CA2010007_031_031-2023060509450.660 ppm
2023-06-06CA2010007_051_051-2023060608200.340 ppm
2023-06-06CA2010007_002_002-202306060822ND
2023-06-06CA2010007_013_013-2023060610000.490 ppm
2023-06-06CA2010007_028_028-2023060610140.110 ppm
2023-06-06CA2010007_017_017-2023060609580.1000 ppm
2023-06-06CA2010007_003_003-2023060608510.180 ppm