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EWG's Tap Water Database — 2019 UPDATE

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Fluoride

Genoa City Waterworks

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.

 

148

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20121.17 ppm24240.750 ppm - 1.50 ppm
20130.742 ppm24240.270 ppm - 1.54 ppm
20140.707 ppm26260.250 ppm - 1.14 ppm
20150.679 ppm24240.450 ppm - 0.960 ppm
20160.750 ppm24240.420 ppm - 1.12 ppm
20170.684 ppm26260.260 ppm - 0.950 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
2012-01-03IW0114701.16 ppm
2012-01-03IW0114701.20 ppm
2012-02-01IW0122611.05 ppm
2012-02-01IW0122611.06 ppm
2012-03-06IW0136080.960 ppm
2012-03-06IW0136081.06 ppm
2012-04-05IW0149991.16 ppm
2012-04-05IW0149991.29 ppm
2012-05-03IW0173760.750 ppm
2012-05-03IW0173760.900 ppm
2012-06-06IW0205141.35 ppm
2012-06-06IW0205141.40 ppm
2012-07-05IX0005071.23 ppm
2012-07-05IX0005071.42 ppm
2012-08-02IX0032831.31 ppm
2012-08-02IX0032831.50 ppm
2012-09-10IX0072501.06 ppm
2012-09-10IX0072501.35 ppm
2012-10-02IX0096041.08 ppm
2012-10-02IX0096041.27 ppm
2012-11-05IX0113351.21 ppm
2012-11-05IX0113351.32 ppm
2012-12-04IX0125750.920 ppm
2012-12-04IX0125751.04 ppm
2013-01-02IX0135271.34 ppm
2013-01-02IX0135271.54 ppm
2013-02-05IX0151530.310 ppm
2013-02-05IX0151530.480 ppm
2013-03-04IX0164580.350 ppm
2013-03-04IX0164580.450 ppm
2013-04-01IX0183010.270 ppm
2013-04-01IX0183010.430 ppm
2013-05-01712430010.719 ppm
2013-05-01712430010.890 ppm
2013-06-10781470010.760 ppm
2013-06-10781470010.770 ppm
2013-07-08849670010.708 ppm
2013-07-08849670010.890 ppm
2013-08-07905770010.790 ppm
2013-08-07905770010.814 ppm
2013-09-05972150010.880 ppm
2013-09-05972150011.01 ppm
2013-10-021023460010.769 ppm
2013-10-021023460010.920 ppm
2013-11-041081450010.500 ppm
2013-11-041081450010.714 ppm
2013-12-031121110010.710 ppm
2013-12-031121110010.800 ppm
2014-01-131164140010.735 ppm
2014-01-131164140010.790 ppm
2014-02-031189170010.627 ppm
2014-02-031189170010.710 ppm
2014-03-041224640010.653 ppm
2014-03-041224640010.740 ppm
2014-04-011261200010.634 ppm
2014-04-011261200010.790 ppm
2014-04-224040873-010.250 ppm
2014-04-224040870-010.500 ppm
2014-05-061312430010.616 ppm
2014-05-061312430010.670 ppm
2014-06-041377970010.530 ppm
2014-06-041377970011.14 ppm
2014-07-021440930010.711 ppm
2014-07-021440930010.800 ppm
2014-08-041512940010.706 ppm
2014-08-041512940010.750 ppm
2014-09-031551460010.820 ppm
2014-09-031551460010.837 ppm
2014-10-011614440010.610 ppm
2014-10-011614440010.981 ppm
2014-11-031673060010.620 ppm
2014-11-031673060010.743 ppm
2014-12-011711540010.639 ppm
2014-12-011711540010.780 ppm
2015-01-061749710010.579 ppm
2015-01-061749710010.650 ppm
2015-02-031785820010.560 ppm
2015-02-031785820010.656 ppm
2015-03-031822150010.630 ppm
2015-03-031822150010.671 ppm
2015-04-011859090010.820 ppm
2015-04-011859090010.960 ppm
2015-05-041921020010.588 ppm
2015-05-041921020010.780 ppm
2015-06-011977100010.710 ppm
2015-06-011977100010.948 ppm
2015-07-062042690010.580 ppm
2015-07-062042690010.777 ppm
2015-08-042102170010.450 ppm
2015-08-042102170010.714 ppm
2015-09-082167060010.710 ppm
2015-09-082167060010.720 ppm
2015-10-012226420010.450 ppm
2015-10-012226420010.508 ppm
2015-11-022269830010.659 ppm
2015-11-022269830010.780 ppm
2015-12-012310380010.675 ppm
2015-12-012310380010.710 ppm
2016-01-062360240010.664 ppm
2016-01-062360240010.880 ppm
2016-02-032383840010.420 ppm
2016-02-032383840010.495 ppm
2016-03-022421850010.730 ppm
2016-03-022421850010.837 ppm
2016-04-042475280010.663 ppm
2016-04-042475280010.730 ppm
2016-05-032524170010.560 ppm
2016-05-032524170010.573 ppm
2016-06-072603640010.460 ppm
2016-06-072603640010.589 ppm
2016-07-052656210010.790 ppm
2016-07-052656210010.905 ppm
2016-08-012704320010.720 ppm
2016-08-012704320010.900 ppm
2016-09-012764920010.640 ppm
2016-09-012764920010.669 ppm
2016-10-102838750010.810 ppm
2016-10-102838750010.946 ppm
2016-11-072886520010.957 ppm
2016-11-072886520010.990 ppm
2016-12-012918590010.959 ppm
2016-12-012918590011.12 ppm
2017-01-042956340010.620 ppm
2017-01-042956340010.689 ppm
2017-02-063004850010.691 ppm
2017-02-063004850010.900 ppm
2017-03-013033080010.694 ppm
2017-03-013033080010.810 ppm
2017-04-043094420010.618 ppm
2017-04-043094420010.820 ppm
2017-05-043149580010.617 ppm
2017-05-043149580010.870 ppm
2017-06-083220580010.724 ppm
2017-06-083220580010.950 ppm
2017-07-063279210010.630 ppm
2017-07-063279210010.637 ppm
2017-07-2517G0983-010.260 ppm
2017-07-2517G0984-010.480 ppm
2017-08-013340160010.643 ppm
2017-08-013340160010.650 ppm
2017-09-053404980010.625 ppm
2017-09-053404980010.870 ppm
2017-10-033473690010.639 ppm
2017-10-033473690010.650 ppm
2017-11-023528190010.566 ppm
2017-11-023528190010.800 ppm
2017-12-043582280010.642 ppm
2017-12-043582280010.680 ppm