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EWG's Tap Water Database — 2021 UPDATE

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Fluoride

North Springs Improvement 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.

 

36

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.594 ppm330.500 ppm - 0.642 ppm
20150.500 ppm220.500 ppm
20160.678 ppm220.678 ppm
20170.593 ppm220.593 ppm
20180.568 ppm770.542 ppm - 0.603 ppm
20190.548 ppm20200.479 ppm - 0.612 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 Result
2014-04-160.500 ppm
2014-10-070.642 ppm
2014-10-070.641 ppm
2015-04-160.500 ppm
2015-04-160.500 ppm
2016-04-200.678 ppm
2016-04-200.678 ppm
2017-04-130.593 ppm
2017-04-130.593 ppm
2018-04-240.603 ppm
2018-04-240.603 ppm
2018-08-060.544 ppm
2018-10-150.563 ppm
2018-10-150.542 ppm
2018-12-180.559 ppm
2018-12-180.559 ppm
2019-02-050.560 ppm
2019-02-050.550 ppm
2019-03-050.541 ppm
2019-03-050.523 ppm
2019-04-080.550 ppm
2019-04-080.556 ppm
2019-04-240.590 ppm
2019-04-240.590 ppm
2019-05-140.585 ppm
2019-05-140.612 ppm
2019-06-110.479 ppm
2019-06-110.534 ppm
2019-07-080.510 ppm
2019-07-080.503 ppm
2019-09-100.542 ppm
2019-10-080.575 ppm
2019-10-080.575 ppm
2019-11-120.588 ppm
2019-12-160.486 ppm
2019-12-160.505 ppm