EWG's Tap Water Database — 2019 UPDATE



Forrest 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.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20120.790 ppm27270.600 ppm - 1.07 ppm
20130.746 ppm25250.540 ppm - 0.880 ppm
20140.682 ppm2322ND - 0.930 ppm
20150.751 ppm24240.430 ppm - 0.950 ppm
20160.813 ppm30300.590 ppm - 2.57 ppm
20170.828 ppm28280.640 ppm - 1.21 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
2012-01-241203000170.770 ppm
2012-01-241203000160.730 ppm
2012-02-05Y804600040.800 ppm
2012-02-291207300040.660 ppm
2012-02-291207300050.780 ppm
2012-03-291210000170.870 ppm
2012-03-291210000180.650 ppm
2012-04-111211400090.900 ppm
2012-04-111211400080.830 ppm
2012-04-251212800020.720 ppm
2012-04-251212800030.850 ppm
2012-05-301216300160.780 ppm
2012-05-311216300150.850 ppm
2012-06-281219100060.870 ppm
2012-06-281219100070.600 ppm
2012-07-241221200070.880 ppm
2012-07-241221200080.860 ppm
2012-08-071222700020.810 ppm
2012-08-071222700010.920 ppm
2012-09-051226100090.820 ppm
2012-09-051226100081.07 ppm
2012-10-181230300050.620 ppm
2012-10-181230300060.750 ppm
2012-11-151233800130.700 ppm
2012-11-151233800120.730 ppm
2012-12-141235500090.770 ppm
2012-12-141235500100.730 ppm
2013-01-231303500070.850 ppm
2013-01-231303500080.790 ppm
2013-02-121304400020.700 ppm
2013-02-121304400010.780 ppm
2013-02-281307000170.540 ppm
2013-02-281307000180.720 ppm
2013-03-081308500240.670 ppm
2013-03-181308500230.640 ppm
2013-04-221312100210.740 ppm
2013-04-221312100220.720 ppm
2013-05-131314800090.710 ppm
2013-05-131314800080.700 ppm
2013-06-171317500200.770 ppm
2013-07-171321100060.650 ppm
2013-07-171321100070.790 ppm
2013-08-131323200270.800 ppm
2013-08-131323200260.880 ppm
2013-09-111326800060.790 ppm
2013-09-111326800050.740 ppm
2013-10-081329500070.740 ppm
2013-10-081329500060.760 ppm
2013-11-071332400120.720 ppm
2013-11-071332400130.780 ppm
2013-12-091336500170.820 ppm
2013-12-091336500160.840 ppm
2014-01-101401600420.930 ppm
2014-01-101401600430.720 ppm
2014-02-061404900200.600 ppm
2014-02-061404900210.720 ppm
2014-03-051407600240.710 ppm
2014-03-051407600250.650 ppm
2014-04-031410400170.670 ppm
2014-04-031410400180.710 ppm
2014-05-061413200410.740 ppm
2014-05-061413200400.780 ppm
2014-06-061416700220.680 ppm
2014-06-061416700230.630 ppm
2014-07-161421100030.770 ppm
2014-07-161421100040.600 ppm
2014-08-151423700170.800 ppm
2014-08-151423700150.670 ppm
2014-09-031425800270.680 ppm
2014-09-031425800260.860 ppm
2014-10-06Y1428600300.760 ppm
2014-10-06Y1428600320.710 ppm
2014-12-08Y1434900230.680 ppm
2014-12-08Y1434900240.620 ppm
2015-01-16Y1502600140.710 ppm
2015-01-16Y1502600150.430 ppm
2015-02-27Y1507500190.760 ppm
2015-02-27Y1507500180.520 ppm
2015-03-16Y1508200230.460 ppm
2015-03-16Y1508200240.620 ppm
2015-04-10Y1511100420.600 ppm
2015-04-10Y1511100410.730 ppm
2015-05-05Y1513400390.750 ppm
2015-05-05Y1513400400.790 ppm
2015-06-11Y1517400070.800 ppm
2015-06-11Y1517400080.660 ppm
2015-07-14Y1520200240.870 ppm
2015-07-14Y1520200320.810 ppm
2015-08-12Y1523600100.800 ppm
2015-08-12Y1523600110.930 ppm
2015-09-18Y1527100100.950 ppm
2015-09-18Y1527100110.850 ppm
2015-10-14Y1529900190.830 ppm
2015-10-14Y1529900180.810 ppm
2015-11-03Y1531300430.810 ppm
2015-11-03Y1531300440.880 ppm
2015-12-08Y1535200100.860 ppm
2015-12-08Y1535200110.800 ppm
2016-01-11Y1602000200.800 ppm
2016-01-11Y1602000210.730 ppm
2016-02-09Y1604700300.840 ppm
2016-02-09Y1604700310.840 ppm
2016-02-16Y1604900042.57 ppm
2016-02-16Y1604900061.01 ppm
2016-03-10Y1608100420.620 ppm
2016-03-10Y1608100430.830 ppm
2016-03-28Y1609500140.820 ppm
2016-04-05Y1610400390.670 ppm
2016-04-05Y1610400420.800 ppm
2016-04-20Y1611600330.650 ppm
2016-05-02Y1613000160.620 ppm
2016-05-02Y1613000170.820 ppm
2016-06-13Y1617900400.820 ppm
2016-06-13Y1617900410.830 ppm
2016-07-06Y1619300130.780 ppm
2016-07-08Y1620000070.760 ppm
2016-07-08Y1620000080.640 ppm
2016-08-03Y1622800150.820 ppm
2016-08-03Y1622800160.800 ppm
2016-09-14Y1627000100.760 ppm
2016-09-14Y1627000110.710 ppm
2016-10-03Y1628800600.810 ppm
2016-10-04Y1628800980.770 ppm
2016-10-04Y1628801000.620 ppm
2016-11-21Y1633400070.750 ppm
2016-11-21Y1633400090.590 ppm
2016-12-13Y1636400030.730 ppm
2016-12-13Y1636400040.590 ppm
2017-01-09Y1701200660.690 ppm
2017-01-09Y1701200670.640 ppm
2017-02-08Y1704600260.660 ppm
2017-02-08Y1704600280.720 ppm
2017-03-13Y1708600200.830 ppm
2017-03-17Y1708600190.750 ppm
2017-04-03Y1709600070.830 ppm
2017-04-03Y1710000270.860 ppm
2017-04-19Y1712100040.750 ppm
2017-04-19Y1712100050.790 ppm
2017-05-24Y1715600010.810 ppm
2017-05-24Y1715600021.21 ppm
2017-06-05Y1717700120.840 ppm
2017-06-05Y1717700130.820 ppm
2017-07-03Y1719100351.03 ppm
2017-07-14Y1720500590.850 ppm
2017-07-14Y1720500600.950 ppm
2017-08-03Y1722600460.880 ppm
2017-08-03Y1722600470.730 ppm
2017-09-25Y1727600210.680 ppm
2017-09-25Y1727600220.870 ppm
2017-10-03Y1728200480.950 ppm
2017-10-18Y1730300130.820 ppm
2017-10-18Y1730300140.860 ppm
2017-11-15Y1733800080.740 ppm
2017-11-15Y1733800090.910 ppm
2017-12-07Y1735400420.940 ppm
2017-12-18Y1735400410.770 ppm