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EWG's Tap Water Database — 2019 UPDATE

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Fluoride

Lake Mills 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.

 

150

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20121.19 ppm24241.000 ppm - 1.81 ppm
20131.21 ppm24241.000 ppm - 1.46 ppm
20140.843 ppm27270.0990 ppm - 1.20 ppm
20150.767 ppm24240.400 ppm - 1.20 ppm
20160.682 ppm24240.340 ppm - 0.840 ppm
20170.674 ppm27270.250 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
2012-01-09IW0116021.21 ppm
2012-01-09IW0116021.81 ppm
2012-02-06IW0123221.000 ppm
2012-02-06IW0123221.22 ppm
2012-03-05IW0133241.11 ppm
2012-03-05IW0133241.19 ppm
2012-04-09IW0150741.19 ppm
2012-04-09IW0150741.21 ppm
2012-05-07IW0174551.05 ppm
2012-05-07IW0174551.09 ppm
2012-06-18IW0213191.17 ppm
2012-06-18IW0213191.19 ppm
2012-07-16IX0012751.24 ppm
2012-07-16IX0012751.25 ppm
2012-08-06IX0033631.21 ppm
2012-08-06IX0033631.24 ppm
2012-09-04IX0062661.11 ppm
2012-09-04IX0062661.20 ppm
2012-10-16IX0100481.10 ppm
2012-10-16IX0100481.19 ppm
2012-11-05IX0110751.09 ppm
2012-11-05IX0110751.18 ppm
2012-12-03IX0122691.16 ppm
2012-12-03IX0122691.24 ppm
2013-01-14IX0138841.000 ppm
2013-01-14IX0138841.21 ppm
2013-02-04IX0146601.18 ppm
2013-02-04IX0146601.19 ppm
2013-03-04IX0161871.16 ppm
2013-03-04IX0161871.19 ppm
2013-04-08IX0183171.12 ppm
2013-04-08IX0183171.20 ppm
2013-05-14726940011.26 ppm
2013-05-14726940011.43 ppm
2013-06-12788420011.27 ppm
2013-06-12788420011.46 ppm
2013-07-16856360011.11 ppm
2013-07-16856360011.18 ppm
2013-08-20927600011.21 ppm
2013-08-20927600011.23 ppm
2013-09-17981240011.18 ppm
2013-09-17981240011.24 ppm
2013-10-091033150011.27 ppm
2013-10-091033150011.32 ppm
2013-11-051074630011.15 ppm
2013-11-051074630011.21 ppm
2013-12-091121950011.13 ppm
2013-12-091121950011.19 ppm
2014-01-081153140011.18 ppm
2014-01-081153140011.20 ppm
2014-02-241206060011.10 ppm
2014-02-241206060011.20 ppm
2014-03-191240790011.10 ppm
2014-03-191240790011.20 ppm
2014-04-081266440010.899 ppm
2014-04-081266440011.07 ppm
2014-05-061306950011.04 ppm
2014-05-061306950011.13 ppm
2014-06-107960350.0990 ppm
2014-06-107960340.120 ppm
2014-06-107960330.120 ppm
2014-06-231405710010.900 ppm
2014-06-231405710010.960 ppm
2014-07-221466640011.08 ppm
2014-07-221466640011.17 ppm
2014-08-201525160010.860 ppm
2014-08-201525160010.862 ppm
2014-09-161574790010.596 ppm
2014-09-161574790010.600 ppm
2014-10-201643280010.695 ppm
2014-10-201643280010.730 ppm
2014-11-111677970010.640 ppm
2014-11-111677970010.651 ppm
2014-12-081713390010.770 ppm
2014-12-081713390010.795 ppm
2015-01-061744590010.649 ppm
2015-01-061744590010.700 ppm
2015-02-171798070011.01 ppm
2015-02-171798070011.01 ppm
2015-03-171838000010.999 ppm
2015-03-171838000011.01 ppm
2015-04-201885310010.788 ppm
2015-04-201885310010.800 ppm
2015-05-181938510010.783 ppm
2015-05-181938510010.830 ppm
2015-06-151994520010.678 ppm
2015-06-151994520010.770 ppm
2015-07-212069150010.672 ppm
2015-07-212069150010.770 ppm
2015-08-182123250010.740 ppm
2015-08-182123250011.20 ppm
2015-09-212185630010.680 ppm
2015-09-212185630010.682 ppm
2015-10-132232940010.400 ppm
2015-10-132232940010.684 ppm
2015-11-172289070010.678 ppm
2015-11-172289070010.730 ppm
2015-12-152327480010.490 ppm
2015-12-152327480010.659 ppm
2016-01-192361220010.570 ppm
2016-01-192361220010.664 ppm
2016-02-172401280010.690 ppm
2016-02-172401280010.761 ppm
2016-03-142436600010.704 ppm
2016-03-142436600010.840 ppm
2016-04-202497710010.689 ppm
2016-04-202497710010.780 ppm
2016-05-232558630010.627 ppm
2016-05-232558630010.650 ppm
2016-06-222620300010.430 ppm
2016-06-222620300010.650 ppm
2016-07-192669950010.738 ppm
2016-07-192669950010.760 ppm
2016-08-172726660010.657 ppm
2016-08-172726660010.690 ppm
2016-09-212793080010.751 ppm
2016-09-212793080010.790 ppm
2016-10-172840830010.707 ppm
2016-10-172840830010.740 ppm
2016-11-212898450010.690 ppm
2016-11-212898450010.815 ppm
2016-12-122923360010.340 ppm
2016-12-122923360010.646 ppm
2017-01-232970150010.250 ppm
2017-01-232970150010.300 ppm
2017-02-223011920010.560 ppm
2017-02-223011920010.569 ppm
2017-03-019755730.520 ppm
2017-03-089767250.720 ppm
2017-03-089767280.820 ppm
2017-03-143039480010.700 ppm
2017-03-143039480010.709 ppm
2017-04-193107930010.779 ppm
2017-04-193107930010.930 ppm
2017-05-103150250010.778 ppm
2017-05-103150250010.950 ppm
2017-06-203229700010.420 ppm
2017-06-203229700010.764 ppm
2017-07-183291020010.690 ppm
2017-07-183291020010.748 ppm
2017-08-213369240010.490 ppm
2017-08-213369240010.761 ppm
2017-09-183426300010.420 ppm
2017-09-183426300010.718 ppm
2017-10-183497700010.610 ppm
2017-10-183497700010.838 ppm
2017-11-203553200010.750 ppm
2017-11-203553200010.823 ppm
2017-12-113584100010.740 ppm
2017-12-113584100010.832 ppm