EWG's Tap Water Database — 2019 UPDATE



Geneva City

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
20120.651 ppm14140.000700 ppm - 0.800 ppm
20130.693 ppm14140.000800 ppm - 0.900 ppm
20140.692 ppm15150.600 ppm - 0.800 ppm
20150.610 ppm11110.500 ppm - 0.800 ppm
20160.529 ppm13130.400 ppm - 0.700 ppm
20170.604 ppm12120.400 ppm - 0.800 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
2012-01-18201213090 - FL0.800 ppm
2012-02-09SB43674-08 - IOC0.720 ppm
2012-02-15201213199 - FL0.600 ppm
2012-03-14201213326 - FL0.600 ppm
2012-04-18EHS 1200011357-00.600 ppm
2012-05-16EHS1200014820-SR0.800 ppm
2012-06-13EHS1200018196-SR0.700 ppm
2012-07-23EHS1200023142-SR0.800 ppm
2012-08-21EHS1200026915-SR0.700 ppm
2012-09-13EHS1200029769-SR0.600 ppm
2012-10-17EHS1200033965-SR0.700 ppm
2012-10-18EHS1200033965-SR0.700 ppm
2012-11-13EHS1200036928-SR0.800 ppm
2012-12-11EHS1200040024-SR0.000700 ppm
2013-01-15EHS1300001956-SR0.700 ppm
2013-02-06SB64191-IOC0.704 ppm
2013-02-12EHS1300004832-SR0.800 ppm
2013-03-13EHS1300007024-SR0.700 ppm
2013-04-12EHS1300010852-SR0.800 ppm
2013-05-151300013898-FLUO0.700 ppm
2013-06-121300016725-FLUO0.700 ppm
2013-07-171300021123-FLUO0.900 ppm
2013-08-151300025079-FLUO0.700 ppm
2013-09-18EHS1300030065-SR0.800 ppm
2013-10-16EHS1300032454-SR0.900 ppm
2013-11-13EHS1300035501-SR0.600 ppm
2013-12-10EHS1300038386-SR0.000800 ppm
2013-12-10EHS1300039378-SR0.700 ppm
2014-01-17EHS1400001933-SR0.700 ppm
2014-02-12EHS1400005258-SR0.700 ppm
2014-02-13SB84641-IOC0.680 ppm
2014-03-12EHS1400008396-SR0.700 ppm
2014-05-14EHS1400011715-SR0.700 ppm
2014-05-29EHS14001400014250.600 ppm
2014-06-11EHS1400017005-SR0.700 ppm
2014-07-09EHS1400020047-SR0.800 ppm
2014-07-17EHS1400021197-SR0.700 ppm
2014-08-14EHS1400024493-SR0.700 ppm
2014-08-14EHS1400024678-SR0.600 ppm
2014-09-17EHS1400029445-SR0.700 ppm
2014-10-15EHS1400032772-SR0.700 ppm
2014-11-12EHS1400036030-SR0.700 ppm
2014-12-22EHS1400039850-SR0.700 ppm
2015-02-04R1500835-005-IOC0.610 ppm
2015-02-11EHS1500004835-SR0.700 ppm
2015-03-11EHS1500007525-SR0.800 ppm
2015-04-08EHS15000010163-S0.700 ppm
2015-05-13EHS1500046377-SR0.700 ppm
2015-06-11EHS1500049117-SR0.500 ppm
2015-07-08EHS1500051868-SR0.600 ppm
2015-08-12EHS1500057346-SR0.500 ppm
2015-09-09EHS1500060711-SR0.600 ppm
2015-10-20EHS1500065466-SR0.500 ppm
2015-12-10EHS150007119-SR10.500 ppm
2016-01-14EHS1600001252-SR0.600 ppm
2016-02-10EHS1600004478-SR0.600 ppm
2016-02-17R1601398-001-PRI0.580 ppm
2016-03-09EHS1600011022-SR0.400 ppm
2016-04-06EHS1600017240-SR0.400 ppm
2016-05-11EHA1600022495-SR0.400 ppm
2016-06-08EHS1600027080-SR0.400 ppm
2016-07-06EHS1600031627-SR0.600 ppm
2016-08-10EHS1600037345-SR0.700 ppm
2016-09-14EHS1600043710-SR0.600 ppm
2016-10-06EHS1600047100-SR0.500 ppm
2016-11-02EHS160005071-SR10.600 ppm
2016-12-07EHS1600055697-SR0.500 ppm
2017-01-18EHS1700002554-SR0.400 ppm
2017-02-08EHS1700007619-SR0.500 ppm
2017-02-15R1701418-001-IOC0.450 ppm
2017-03-08EHS1700013390-SR0.500 ppm
2017-04-05EHS1700018934-SR0.500 ppm
2017-05-03EHS1700023925-SR0.700 ppm
2017-06-12EHS1700029823-SR0.800 ppm
2017-07-10EHS1700035332-SR0.700 ppm
2017-09-07EHS1700045481-SR0.700 ppm
2017-10-04EHS1700050008-010.700 ppm
2017-11-08EHS1700055570-010.700 ppm
2017-12-11EHS1700059638-010.600 ppm