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EWG's Tap Water Database — 2019 UPDATE

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Fluoride

San Fernando Water Department

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.

 

78

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20120.314 ppm15150.220 ppm - 0.370 ppm
20130.297 ppm12120.190 ppm - 0.360 ppm
20140.320 ppm12120.240 ppm - 0.370 ppm
20150.295 ppm15150.210 ppm - 0.360 ppm
20160.298 ppm12120.220 ppm - 0.360 ppm
20170.318 ppm12120.220 ppm - 0.370 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
2012-01-049590-002-08500.350 ppm
2012-01-049590-003-09250.340 ppm
2012-01-049590-004-08250.220 ppm
2012-01-189590-002-10350.360 ppm
2012-01-189590-003-10000.350 ppm
2012-01-189590-004-09200.250 ppm
2012-04-189590-004-07000.230 ppm
2012-04-189590-003-10100.370 ppm
2012-04-189590-002-07150.360 ppm
2012-07-119590-004-07550.250 ppm
2012-07-119590-002-08150.350 ppm
2012-07-119590-003-08400.350 ppm
2012-10-179590-004-09300.240 ppm
2012-10-179590-002-09450.350 ppm
2012-10-179590-003-10200.340 ppm
2013-01-099590-004-08350.220 ppm
2013-01-099590-002-09450.330 ppm
2013-01-099590-003-09200.320 ppm
2013-04-179590-003-08500.320 ppm
2013-04-179590-002-07300.320 ppm
2013-04-179590-004-07100.190 ppm
2013-07-109590-003-09500.330 ppm
2013-07-109590-004-06250.240 ppm
2013-07-109590-002-09200.340 ppm
2013-10-099590-003-09350.340 ppm
2013-10-099590-004-08350.250 ppm
2013-10-099590-002-09100.360 ppm
2014-01-089590-002-08300.350 ppm
2014-01-089590-004-08550.260 ppm
2014-01-089590-003-10000.340 ppm
2014-04-099590-002-09400.350 ppm
2014-04-099590-003-10500.340 ppm
2014-04-099590-004-08550.240 ppm
2014-07-119590-002-09100.370 ppm
2014-07-119590-003-09450.360 ppm
2014-07-119590-004-08450.270 ppm
2014-10-089590-004-09100.260 ppm
2014-10-089590-003-10200.340 ppm
2014-10-089590-002-09450.360 ppm
2015-01-149590-002-09150.340 ppm
2015-01-149590-003-10150.320 ppm
2015-01-149590-004-08500.210 ppm
2015-04-089590-004-08450.230 ppm
2015-04-089590-003-11300.330 ppm
2015-04-089590-003-11250.320 ppm
2015-04-089590-004-08300.230 ppm
2015-04-089590-002-10000.360 ppm
2015-04-089590-002-09450.340 ppm
2015-07-219590-004-09050.250 ppm
2015-07-219590-002-09450.340 ppm
2015-07-219590-003-10450.260 ppm
2015-10-149590-004-07450.230 ppm
2015-10-149590-002-08020.340 ppm
2015-10-149590-003-09250.320 ppm
2016-01-209590-004-07150.240 ppm
2016-01-209590-002-07450.360 ppm
2016-01-209590-003-10000.340 ppm
2016-04-069590-003-09450.320 ppm
2016-04-069590-002-06450.350 ppm
2016-04-069590-004-07550.220 ppm
2016-07-139590-003-06400.320 ppm
2016-07-139590-004-06200.250 ppm
2016-07-139590-002-08100.300 ppm
2016-10-129590-003-07250.310 ppm
2016-10-129590-004-06550.220 ppm
2016-10-129590-002-08000.350 ppm
2017-01-259590-002-07150.370 ppm
2017-01-259590-004-08000.220 ppm
2017-01-259590-003-08550.350 ppm
2017-04-259590-002-10250.370 ppm
2017-04-259590-003-09480.350 ppm
2017-04-259590-004-08500.260 ppm
2017-07-199590-002-11200.340 ppm
2017-07-199590-003-10350.330 ppm
2017-07-199590-004-09100.260 ppm
2017-10-249590-004-07150.270 ppm
2017-10-249590-003-09250.340 ppm
2017-10-249590-002-07300.360 ppm