EWG's Tap Water Database — 2019 UPDATE



Whittier 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.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20120.280 ppm220.280 ppm
20130.285 ppm220.220 ppm - 0.350 ppm
20140.180 ppm220.170 ppm - 0.190 ppm
20150.200 ppm330.190 ppm - 0.210 ppm
20160.140 ppm110.140 ppm
20170.210 ppm660.200 ppm - 0.220 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
2012-03-139588-009-11300.280 ppm
2012-03-139588-013-10000.280 ppm
2013-05-169588-003-08000.350 ppm
2013-09-179588-010-10100.220 ppm
2014-03-119588-008-09250.170 ppm
2014-03-119588-011-09100.190 ppm
2015-02-249588-009-09300.200 ppm
2015-03-069588-009-10100.210 ppm
2015-03-179588-013-10000.190 ppm
2016-09-139588-010-09100.140 ppm
2017-02-229588-008-11220.220 ppm
2017-02-229588-010-12490.200 ppm
2017-02-229588-011-13300.210 ppm
2017-02-229588-013-10470.200 ppm
2017-03-089588-008-09050.220 ppm
2017-03-089588-011-08550.210 ppm