EWG's Tap Water Database — 2021 UPDATE



Malvern Water Supply

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
20140.917 ppm12120.400 ppm - 2.60 ppm
20150.667 ppm12120.200 ppm - 0.900 ppm
20160.725 ppm12120.400 ppm - 1.000 ppm
20170.892 ppm13130.400 ppm - 2.30 ppm
20180.440 ppm12120.0800 ppm - 0.600 ppm
20190.708 ppm12120.200 ppm - 1.30 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
2014-01-2120294622.60 ppm
2014-02-2420361430.900 ppm
2014-03-1120400380.600 ppm
2014-04-0720444110.400 ppm
2014-05-1320524901.20 ppm
2014-06-0920567460.800 ppm
2014-07-0820629850.700 ppm
2014-08-1220720260.800 ppm
2014-09-0920768500.800 ppm
2014-10-1420863710.800 ppm
2014-11-1820930760.700 ppm
2014-12-0920979970.700 ppm
2015-01-131A50582-010.800 ppm
2015-02-101B50562-010.700 ppm
2015-03-101C50521-010.700 ppm
2015-04-071D50442-010.500 ppm
2015-05-131E50875-010.500 ppm
2015-06-091F50639-010.800 ppm
2015-07-141G51054-030.700 ppm
2015-08-181H51281-030.600 ppm
2015-09-081I50479-030.800 ppm
2015-10-191J51385-030.900 ppm
2015-11-161K51057-030.800 ppm
2015-12-151L51142-030.200 ppm
2016-01-131A60870-030.900 ppm
2016-02-091B60503-030.500 ppm
2016-03-091C60671-031.000 ppm
2016-04-121D60913-030.800 ppm
2016-05-161E61170-030.800 ppm
2016-06-201F61496-030.800 ppm
2016-07-111G60682-030.700 ppm
2016-08-101H60914-040.400 ppm
2016-09-141I61027-040.800 ppm
2016-10-111J60750-040.800 ppm
2016-11-081K60680-040.700 ppm
2016-12-061L60389-040.500 ppm
2017-01-091A70477-040.500 ppm
2017-02-231B71563-040.800 ppm
2017-03-141C70952-040.800 ppm
2017-04-041D70214-040.800 ppm
2017-05-151E71240-040.700 ppm
2017-06-061F70414-040.600 ppm
2017-07-111G70669-040.600 ppm
2017-08-221H71767-040.500 ppm
2017-08-221H71767-010.500 ppm
2017-09-121I70763-042.30 ppm
2017-10-171J71332-042.20 ppm
2017-11-081K70740-040.900 ppm
2017-12-121L70871-040.400 ppm
2018-01-091A80562-040.400 ppm
2018-02-131B80860-040.500 ppm
2018-03-141C81116-040.500 ppm
2018-04-101D80759-040.500 ppm
2018-05-211E81808-040.400 ppm
2018-06-191F81620-040.500 ppm
2018-07-101G80687-040.0800 ppm
2018-08-201H81684-040.500 ppm
2018-09-111I80717-040.600 ppm
2018-10-161J81431-040.200 ppm
2018-11-191K81499-040.600 ppm
2018-12-111L80714-040.500 ppm
2019-01-151A91143-040.700 ppm
2019-02-191B91228-040.500 ppm
2019-03-051C90230-040.800 ppm
2019-04-161D91415-040.200 ppm
2019-05-081E90744-040.900 ppm
2019-06-111F90755-041.000 ppm
2019-07-151G91300-040.800 ppm
2019-08-061H90407-040.700 ppm
2019-09-101I90673-040.500 ppm
2019-10-081J90723-040.500 ppm
2019-11-181K91304-040.600 ppm
2019-12-171L91417-041.30 ppm