Know Your Environment. Protect Your Health.

Fluoride

CTWC - Shoreline Region-Guilford System

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.

 

37

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.520 ppm1311ND - 0.710 ppm
20190.462 ppm550.0300 ppm - 0.580 ppm
20200.513 ppm65ND - 0.810 ppm
20210.320 ppm21ND - 0.640 ppm
20220.317 ppm32ND - 0.490 ppm
20230.450 ppm87ND - 0.710 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
2018-03-30CA11463IOCRND
2018-03-30CA11466IOC10.500 ppm
2018-04-23CA24244IOC1ND
2018-04-23CA24243IOC10.630 ppm
2018-05-22CA51266IOC10.600 ppm
2018-05-22CA51267IOC10.600 ppm
2018-05-22CA51268IOC10.690 ppm
2018-05-22CA51269IOC10.630 ppm
2018-05-22CA51270IOC10.560 ppm
2018-05-22CA51265IOC10.710 ppm
2018-08-13CB099750.660 ppm
2018-10-01IOC 2005072760.580 ppm
2018-10-09IOC 2005083870.600 ppm
2019-01-30IOC1 2005200570.570 ppm
2019-02-27IOCR 2005230020.0300 ppm
2019-04-26IOC1 2005298270.560 ppm
2019-06-24IOC1 2005376250.570 ppm
2019-07-10IOC1 2005399980.580 ppm
2020-01-20IOC1 2005635090.670 ppm
2020-01-21IOC1 2005635160.620 ppm
2020-01-28IOC1 2005642120.810 ppm
2020-02-11IOC1 2005657990.550 ppm
2020-02-11IOCR 200565797ND
2020-02-25IOC1 2005672750.430 ppm
2021-09-30I300072093 3000720940.640 ppm
2021-09-30R300072099 300072100ND
2022-08-15CM056360.490 ppm
2022-08-29CM17831ND
2022-08-29CM178300.460 ppm
2023-02-13CN418580.460 ppm
2023-02-13CN41859ND
2023-09-12CO958740.670 ppm
2023-09-12CO958750.630 ppm
2023-09-12CO958770.420 ppm
2023-10-12CP236290.450 ppm
2023-11-28CP553200.260 ppm
2023-11-29CP564340.710 ppm