moderate Risk

Top 100 Cities with Highest Fluoride Levels

Added for dental health but excessive levels cause bone problems. Below are US cities ranked by their measured Fluoride levels compared to EPA limits. Higher percentages indicate greater concern.

EPA Limit (MCL)

4 ppm

Health Goal (MCLG)

4 ppm

Cities Above 50% of Limit

Cities Exceeding Limit

National Statistics for Fluoride

Cities Tested

515

Average Level

0.559 ppm

Highest Level

2.042 ppm

in Lewiston, ID

People Affected (>50% of limit)

0.0M

Health Effects of Fluoride

Children

Dental fluorosis (tooth discoloration)
Pitting and damage to tooth enamel
Potential impacts on developing brain

Adults

Skeletal fluorosis (bone disease)
Increased bone fracture risk
Joint stiffness and pain
Thyroid problems at high levels

Vulnerable Populations: Infants and young children most susceptible to dental fluorosis. People with kidney problems may accumulate fluoride.

Top 100 Cities by Fluoride Level

Ranked by percentage of the EPA limit, using one real EPA measurement per water system (2012–2019 (SYR4)). Click any city for its full report.

Historical data. Figure shown is the average of the system's 2012–2019 finished-water compliance samples (EPA Six-Year Review 4), non-detects counted as zero. Treat as history, not today's tap water.

Rank	City	State	Level	Period	EPA Limit	% of Limit	Status	Population
#1	Lewiston	Idaho	2.042 ppmAverage of 4 samples	2012–2019	4.000 ppm	51.0%	Elevated	20,000
#2	Easton	Maryland	1.904 ppmAverage of 30 samples	2012–2019	4.000 ppm	47.6%	Within Limit	17,357
#3	Fountain	Colorado	1.764 ppmAverage of 11 samples	2012–2019	4.000 ppm	44.1%	Within Limit	25,130
#4	Buckeye	Arizona	1.439 ppmAverage of 19 samples	2012–2019	4.000 ppm	36.0%	Within Limit	30,377
#5	Maricopa	Arizona	1.427 ppmAverage of 128 samples	2012–2019	4.000 ppm	35.7%	Within Limit	84,000
#6	Alexandria	Louisiana	1.323 ppmAverage of 24 samples	2012–2019	4.000 ppm	33.1%	Within Limit	66,798
#7	Kingman	Arizona	1.185 ppmAverage of 26 samples	2012–2019	4.000 ppm	29.6%	Within Limit	45,000
#8	Dodge City	Kansas	1.143 ppmAverage of 43 samples	2012–2019	4.000 ppm	28.6%	Within Limit	27,104
#9	Joliet	Illinois	1.119 ppmAverage of 32 samples	2012–2019	4.000 ppm	28.0%	Within Limit	160,000
#10	Michigan City	Indiana	1.121 ppmAverage of 8 samples	2012–2019	4.000 ppm	28.0%	Within Limit	33,996
#11	Marion	Iowa	1.100 ppmAverage of 93 samples	2012–2019	4.000 ppm	27.5%	Within Limit	41,623
#12	Seaford	Delaware	1.057 ppmAverage of 309 samples	2012–2019	4.000 ppm	26.4%	Within Limit	6,699
#13	Surprise	Arizona	1.017 ppmAverage of 128 samples	2012–2019	4.000 ppm	25.4%	Within Limit	40,007
#14	Cleveland	Ohio	0.986 ppmAverage of 380 samples	2012–2019	4.000 ppm	24.7%	Within Limit	1,308,955
#15	Toledo	Ohio	0.982 ppmAverage of 8 samples	2012–2019	4.000 ppm	24.5%	Within Limit	360,000
#16	Carpentersville	Illinois	0.976 ppmAverage of 3 samples	2012–2019	4.000 ppm	24.4%	Within Limit	37,983
#17	Akron	Ohio	0.966 ppmAverage of 8 samples	2012–2019	4.000 ppm	24.2%	Within Limit	280,000
#18	Parker	Colorado	0.966 ppmAverage of 51 samples	2012–2019	4.000 ppm	24.2%	Within Limit	75,949
#19	Elkhart	Indiana	0.950 ppmAverage of 12 samples	2012–2019	4.000 ppm	23.8%	Within Limit	46,455
#20	Moline	Illinois	0.953 ppmAverage of 8 samples	2012–2019	4.000 ppm	23.8%	Within Limit	44,500
#21	DeKalb	Illinois	0.953 ppmAverage of 15 samples	2012–2019	4.000 ppm	23.8%	Within Limit	40,290
#22	St. Charles	Illinois	0.953 ppmAverage of 25 samples	2012–2019	4.000 ppm	23.8%	Within Limit	33,103
#23	Galesburg	Illinois	0.951 ppmAverage of 3 samples	2012–2019	4.000 ppm	23.8%	Within Limit	31,620
#24	Palm Desert	California	0.947 ppmAverage of 6 samples	2012–2019	4.000 ppm	23.7%	Within Limit	270,000
#25	Romeoville	Illinois	0.941 ppmAverage of 15 samples	2012–2019	4.000 ppm	23.5%	Within Limit	50,458
#26	Pine Bluff	Arkansas	0.938 ppmAverage of 300 samples	2012–2019	4.000 ppm	23.5%	Within Limit	43,438
#27	Gardner	Kansas	0.940 ppmAverage of 40 samples	2012–2019	4.000 ppm	23.5%	Within Limit	23,942
#28	Oswego	Illinois	0.938 ppmAverage of 22 samples	2012–2019	4.000 ppm	23.4%	Within Limit	38,169
#29	Hanover Park	Illinois	0.936 ppmAverage of 8 samples	2012–2019	4.000 ppm	23.4%	Within Limit	37,470
#30	Hammond	Indiana	0.926 ppmAverage of 8 samples	2012–2019	4.000 ppm	23.2%	Within Limit	78,384
#31	Noblesville	Indiana	0.927 ppmAverage of 9 samples	2012–2019	4.000 ppm	23.2%	Within Limit	45,575
#32	Columbus	Ohio	0.910 ppmAverage of 18 samples	2012–2019	4.000 ppm	22.8%	Within Limit	1,305,946
#33	Lubbock	Texas	0.914 ppmAverage of 17 samples	2012–2019	4.000 ppm	22.8%	Within Limit	275,041
#34	Georgetown	Delaware	0.914 ppmAverage of 256 samples	2012–2019	4.000 ppm	22.8%	Within Limit	7,259
#35	New Bedford	Massachusetts	0.908 ppmAverage of 8 samples	2012–2019	4.000 ppm	22.7%	Within Limit	101,079
#36	Manchester	Connecticut	0.905 ppmAverage of 26 samples	2012–2019	4.000 ppm	22.6%	Within Limit	51,198
#37	Smyrna	Delaware	0.903 ppmAverage of 303 samples	2012–2019	4.000 ppm	22.6%	Within Limit	11,813
#38	Elgin	Illinois	0.899 ppmAverage of 10 samples	2012–2019	4.000 ppm	22.5%	Within Limit	114,797
#39	North Chicago	Illinois	0.900 ppmAverage of 8 samples	2012–2019	4.000 ppm	22.5%	Within Limit	16,813
#40	Burlington	Massachusetts	0.898 ppmAverage of 13 samples	2012–2019	4.000 ppm	22.4%	Within Limit	25,864
#41	Winchester	Kentucky	0.891 ppmAverage of 16 samples	2012–2019	4.000 ppm	22.3%	Within Limit	29,823
#42	Rockford	Illinois	0.889 ppmAverage of 59 samples	2012–2019	4.000 ppm	22.2%	Within Limit	147,051
#43	Peoria	Illinois	0.890 ppmAverage of 21 samples	2012–2019	4.000 ppm	22.2%	Within Limit	137,575
#44	Dover	Delaware	0.885 ppmAverage of 813 samples	2012–2019	4.000 ppm	22.1%	Within Limit	39,491
#45	Rock Island	Illinois	0.881 ppmAverage of 8 samples	2012–2019	4.000 ppm	22.0%	Within Limit	39,018
#46	Murray	Kentucky	0.881 ppmAverage of 10 samples	2012–2019	4.000 ppm	22.0%	Within Limit	26,302
#47	Granite City	Illinois	0.875 ppmAverage of 8 samples	2012–2019	4.000 ppm	21.9%	Within Limit	33,572
#48	Haverhill	Massachusetts	0.870 ppmAverage of 7 samples	2012–2019	4.000 ppm	21.8%	Within Limit	61,277
#49	Wakefield	Massachusetts	0.873 ppmAverage of 8 samples	2012–2019	4.000 ppm	21.8%	Within Limit	27,090
#50	Cincinnati	Ohio	0.863 ppmAverage of 16 samples	2012–2019	4.000 ppm	21.6%	Within Limit	750,200
#51	Fremont	California	0.862 ppmAverage of 133 samples	2012–2019	4.000 ppm	21.6%	Within Limit	344,000
#52	Hartford	Connecticut	0.862 ppmAverage of 24 samples	2012–2019	4.000 ppm	21.5%	Within Limit	390,887
#53	Fall River	Massachusetts	0.859 ppmAverage of 8 samples	2012–2019	4.000 ppm	21.5%	Within Limit	94,000
#54	Bloomington	Illinois	0.856 ppmAverage of 9 samples	2012–2019	4.000 ppm	21.4%	Within Limit	77,610
#55	Crystal Lake	Illinois	0.857 ppmAverage of 15 samples	2012–2019	4.000 ppm	21.4%	Within Limit	40,661
#56	Nicholasville	Kentucky	0.857 ppmAverage of 27 samples	2012–2019	4.000 ppm	21.4%	Within Limit	35,266
#57	New Haven	Connecticut	0.848 ppmAverage of 82 samples	2012–2019	4.000 ppm	21.2%	Within Limit	418,900
#58	Henderson	Kentucky	0.850 ppmAverage of 15 samples	2012–2019	4.000 ppm	21.2%	Within Limit	31,705
#59	Groton	Connecticut	0.848 ppmAverage of 8 samples	2012–2019	4.000 ppm	21.2%	Within Limit	30,200
#60	Lexington	Kentucky	0.842 ppmAverage of 49 samples	2012–2019	4.000 ppm	21.1%	Within Limit	669,042
#61	Shreveport	Louisiana	0.843 ppmAverage of 9 samples	2012–2019	4.000 ppm	21.1%	Within Limit	192,378
#62	Champaign	Illinois	0.843 ppmAverage of 8 samples	2012–2019	4.000 ppm	21.1%	Within Limit	150,000
#63	Russellville	Arkansas	0.845 ppmAverage of 103 samples	2012–2019	4.000 ppm	21.1%	Within Limit	29,260
#64	Aurora	Illinois	0.840 ppmAverage of 10 samples	2012–2019	4.000 ppm	21.0%	Within Limit	183,000
#65	New Britain	Connecticut	0.841 ppmAverage of 8 samples	2012–2019	4.000 ppm	21.0%	Within Limit	73,534
#66	Marlborough	Massachusetts	0.834 ppmAverage of 5 samples	2012–2019	4.000 ppm	20.9%	Within Limit	41,799
#67	Jacksonville	Arkansas	0.838 ppmAverage of 105 samples	2012–2019	4.000 ppm	20.9%	Within Limit	32,875
#68	Temple Terrace	Florida	0.835 ppmAverage of 47 samples	2012–2019	4.000 ppm	20.9%	Within Limit	31,250
#69	Algonquin	Illinois	0.837 ppmAverage of 9 samples	2012–2019	4.000 ppm	20.9%	Within Limit	30,700
#70	Rexburg	Idaho	0.827 ppmAverage of 9 samples	2012–2019	4.000 ppm	20.7%	Within Limit	40,695
#71	Shelbyville	Kentucky	0.826 ppmAverage of 34 samples	2012–2019	4.000 ppm	20.7%	Within Limit	23,760
#72	Pueblo	Colorado	0.819 ppmAverage of 32 samples	2012–2019	4.000 ppm	20.5%	Within Limit	114,070
#73	Waterbury	Connecticut	0.819 ppmAverage of 8 samples	2012–2019	4.000 ppm	20.5%	Within Limit	107,271
#74	Decatur	Illinois	0.821 ppmAverage of 10 samples	2012–2019	4.000 ppm	20.5%	Within Limit	76,122
#75	Danville	Kentucky	0.819 ppmAverage of 16 samples	2012–2019	4.000 ppm	20.5%	Within Limit	32,600
#76	Fort Thomas	Kentucky	0.816 ppmAverage of 64 samples	2012–2019	4.000 ppm	20.4%	Within Limit	259,949
#77	Cambridge	Massachusetts	0.816 ppmAverage of 6 samples	2012–2019	4.000 ppm	20.4%	Within Limit	118,214
#78	Normal	Illinois	0.814 ppmAverage of 4 samples	2012–2019	4.000 ppm	20.4%	Within Limit	52,736
#79	Louisville	Kentucky	0.814 ppmAverage of 44 samples	2012–2019	4.000 ppm	20.3%	Within Limit	806,997
#80	Waukegan	Illinois	0.812 ppmAverage of 8 samples	2012–2019	4.000 ppm	20.3%	Within Limit	87,149
#81	Castle Rock	Colorado	0.802 ppmAverage of 31 samples	2012–2019	4.000 ppm	20.1%	Within Limit	110,298
#82	Columbus	Indiana	0.805 ppmAverage of 4 samples	2012–2019	4.000 ppm	20.1%	Within Limit	51,122
#83	Milford	Delaware	0.803 ppmAverage of 385 samples	2012–2019	4.000 ppm	20.1%	Within Limit	9,800
#84	Twin Falls	Idaho	0.801 ppmAverage of 7 samples	2012–2019	4.000 ppm	20.0%	Within Limit	56,121
#85	Hialeah	Florida	0.793 ppmAverage of 14 samples	2012–2019	4.000 ppm	19.8%	Within Limit	238,000
#86	Jonesboro	Arkansas	0.791 ppmAverage of 361 samples	2012–2019	4.000 ppm	19.8%	Within Limit	81,888
#87	Georgetown	Kentucky	0.794 ppmAverage of 16 samples	2012–2019	4.000 ppm	19.8%	Within Limit	44,608
#88	Moscow	Idaho	0.793 ppmAverage of 5 samples	2012–2019	4.000 ppm	19.8%	Within Limit	26,000
#89	Bristol	Connecticut	0.788 ppmAverage of 16 samples	2012–2019	4.000 ppm	19.7%	Within Limit	52,079
#90	Santa Maria	California	0.782 ppmAverage of 73 samples	2012–2019	4.000 ppm	19.6%	Within Limit	109,477
#91	Lawrence	Massachusetts	0.786 ppmAverage of 7 samples	2012–2019	4.000 ppm	19.6%	Within Limit	89,143
#92	Paragould	Arkansas	0.783 ppmAverage of 99 samples	2012–2019	4.000 ppm	19.6%	Within Limit	31,188
#93	Sahuarita	Arizona	0.783 ppmAverage of 3 samples	2012–2019	4.000 ppm	19.6%	Within Limit	18,178
#94	Fairfield	California	0.779 ppmAverage of 65 samples	2012–2019	4.000 ppm	19.5%	Within Limit	120,377
#95	Bardstown	Kentucky	0.780 ppmAverage of 14 samples	2012–2019	4.000 ppm	19.5%	Within Limit	31,185
#96	Florence	Arizona	0.780 ppmAverage of 3 samples	2012–2019	4.000 ppm	19.5%	Within Limit	15,900
#97	Houma	Louisiana	0.781 ppmAverage of 7 samples	2012–2019	4.000 ppm	19.5%	Within Limit	11,658
#98	Key West	Florida	0.775 ppmAverage of 123 samples	2012–2019	4.000 ppm	19.4%	Within Limit	86,000
#99	Commerce City	Colorado	0.776 ppmAverage of 264 samples	2012–2019	4.000 ppm	19.4%	Within Limit	75,559
#100	Benton	Arkansas	0.776 ppmAverage of 200 samples	2012–2019	4.000 ppm	19.4%	Within Limit	30,681

Common Sources of Fluoride

Water fluoridation (intentionally added at 0.7 mg/L)
Natural geological deposits
Industrial discharge
Phosphate fertilizer production
Aluminum smelting

How to Remove Fluoride from Drinking Water

Reverse Osmosis

90-95% effective

Most effective home option for fluoride removal.

Activated Alumina

90%+ effective

Specialized media for fluoride. Point-of-use systems.

Bone Char Carbon

80-90% effective

Natural option for fluoride reduction.

View Filter Recommendations

Frequently Asked Questions About Fluoride

Why is fluoride added to water?

Water fluoridation at 0.7 mg/L is added to prevent tooth decay. The EPA limit of 4 mg/L protects against bone disease from natural or industrial contamination.

Do standard carbon filters remove fluoride?

No. Standard activated carbon does not remove fluoride. You need reverse osmosis or activated alumina.

Is fluoridated water safe?

CDC recommends fluoridation at 0.7 mg/L as safe and beneficial. Concerns arise only at levels approaching EPA limit of 4 mg/L.

Browse Other Contaminants

Lead Arsenic PFAS (Forever Chemicals)Nitrates Chromium-6 (Hexavalent Chromium)Chlorine Copper Mercury View All Contaminants

Back to All Contaminant Rankings

Loading water data...

Top 100 Cities by Fluoride Level

Ranked by percentage of the EPA limit, using one real EPA measurement per water system (2012–2019 (SYR4)). Click any city for its full report.

Rank

City

State

Level

Period

EPA Limit

% of Limit

Status

Population

Lewiston

Idaho

2.042 ppmAverage of 4 samples

2012–2019

4.000 ppm

51.0%

Elevated

20,000

Easton

Maryland

1.904 ppmAverage of 30 samples

2012–2019

4.000 ppm

47.6%

Within Limit

17,357

Fountain

Colorado

1.764 ppmAverage of 11 samples

2012–2019

4.000 ppm

44.1%

Within Limit

25,130

Buckeye

Arizona

1.439 ppmAverage of 19 samples

2012–2019

4.000 ppm

36.0%

Within Limit

30,377

Maricopa

Arizona

1.427 ppmAverage of 128 samples

2012–2019

4.000 ppm

35.7%

Within Limit

84,000

Alexandria

Louisiana

1.323 ppmAverage of 24 samples

2012–2019

4.000 ppm

33.1%

Within Limit

66,798

Kingman

Arizona

1.185 ppmAverage of 26 samples

2012–2019

4.000 ppm

29.6%

Within Limit

45,000

Dodge City

Kansas

1.143 ppmAverage of 43 samples

2012–2019

4.000 ppm

28.6%

Within Limit

27,104

Joliet

Illinois

1.119 ppmAverage of 32 samples

2012–2019

4.000 ppm

28.0%

Within Limit

160,000

#10

Michigan City

Indiana

1.121 ppmAverage of 8 samples

2012–2019

4.000 ppm

28.0%

Within Limit

33,996

#11

Marion

Iowa

1.100 ppmAverage of 93 samples

2012–2019

4.000 ppm

27.5%

Within Limit

41,623

#12

Seaford

Delaware

1.057 ppmAverage of 309 samples

2012–2019

4.000 ppm

26.4%

Within Limit

6,699

#13

Surprise

Arizona

1.017 ppmAverage of 128 samples

2012–2019

4.000 ppm

25.4%

Within Limit

40,007

#14

Cleveland

Ohio

0.986 ppmAverage of 380 samples

2012–2019

4.000 ppm

24.7%

Within Limit

1,308,955

#15

Toledo

Ohio

0.982 ppmAverage of 8 samples

2012–2019

4.000 ppm

24.5%

Within Limit

360,000

#16

Carpentersville

Illinois

0.976 ppmAverage of 3 samples

2012–2019

4.000 ppm

24.4%

Within Limit

37,983

#17

Akron

Ohio

0.966 ppmAverage of 8 samples

2012–2019

4.000 ppm

24.2%

Within Limit

280,000

#18

Parker

Colorado

0.966 ppmAverage of 51 samples

2012–2019

4.000 ppm

24.2%

Within Limit

75,949

#19

Elkhart

Indiana

0.950 ppmAverage of 12 samples

2012–2019

4.000 ppm

23.8%

Within Limit

46,455

#20

Moline

Illinois

0.953 ppmAverage of 8 samples

2012–2019

4.000 ppm

23.8%

Within Limit

44,500

#21

DeKalb

Illinois

0.953 ppmAverage of 15 samples

2012–2019

4.000 ppm

23.8%

Within Limit

40,290

#22

St. Charles

Illinois

0.953 ppmAverage of 25 samples

2012–2019

4.000 ppm

23.8%

Within Limit

33,103

#23

Galesburg

Illinois

0.951 ppmAverage of 3 samples

2012–2019

4.000 ppm

23.8%

Within Limit

31,620

#24

Palm Desert

California

0.947 ppmAverage of 6 samples

2012–2019

4.000 ppm

23.7%

Within Limit

270,000

#25

Romeoville

Illinois

0.941 ppmAverage of 15 samples

2012–2019

4.000 ppm

23.5%

Within Limit

50,458

#26

Pine Bluff

Arkansas

0.938 ppmAverage of 300 samples

2012–2019

4.000 ppm

23.5%

Within Limit

43,438

#27

Gardner

Kansas

0.940 ppmAverage of 40 samples

2012–2019

4.000 ppm

23.5%

Within Limit

23,942

#28

Oswego

Illinois

0.938 ppmAverage of 22 samples

2012–2019

4.000 ppm

23.4%

Within Limit

38,169

#29

Hanover Park

Illinois

0.936 ppmAverage of 8 samples

2012–2019

4.000 ppm

23.4%

Within Limit

37,470

#30

Hammond

Indiana

0.926 ppmAverage of 8 samples

2012–2019

4.000 ppm

23.2%

Within Limit

78,384

#31

Noblesville

Indiana

0.927 ppmAverage of 9 samples

2012–2019

4.000 ppm

23.2%

Within Limit

45,575

#32

Columbus

Ohio

0.910 ppmAverage of 18 samples

2012–2019

4.000 ppm

22.8%

Within Limit

1,305,946

#33

Lubbock

Texas

0.914 ppmAverage of 17 samples

2012–2019

4.000 ppm

22.8%

Within Limit

275,041

#34

Georgetown

Delaware

0.914 ppmAverage of 256 samples

2012–2019

4.000 ppm

22.8%

Within Limit

7,259

#35

New Bedford

Massachusetts

0.908 ppmAverage of 8 samples

2012–2019

4.000 ppm

22.7%

Within Limit

101,079

#36

Manchester

Connecticut

0.905 ppmAverage of 26 samples

2012–2019

4.000 ppm

22.6%

Within Limit

51,198

#37

Smyrna

Delaware

0.903 ppmAverage of 303 samples

2012–2019

4.000 ppm

22.6%

Within Limit

11,813

#38

Elgin

Illinois

0.899 ppmAverage of 10 samples

2012–2019

4.000 ppm

22.5%

Within Limit

114,797

#39

North Chicago

Illinois

0.900 ppmAverage of 8 samples

2012–2019

4.000 ppm

22.5%

Within Limit

16,813

#40

Burlington

Massachusetts

0.898 ppmAverage of 13 samples

2012–2019

4.000 ppm

22.4%

Within Limit

25,864

#41

Winchester

Kentucky

0.891 ppmAverage of 16 samples

2012–2019

4.000 ppm

22.3%

Within Limit

29,823

#42

Rockford

Illinois

0.889 ppmAverage of 59 samples

2012–2019

4.000 ppm

22.2%

Within Limit

147,051

#43

Peoria

Illinois

0.890 ppmAverage of 21 samples

2012–2019

4.000 ppm

22.2%

Within Limit

137,575

#44

Dover

Delaware

0.885 ppmAverage of 813 samples

2012–2019

4.000 ppm

22.1%

Within Limit

39,491

#45

Rock Island

Illinois

0.881 ppmAverage of 8 samples

2012–2019

4.000 ppm

22.0%

Within Limit

39,018

#46

Murray

Kentucky

0.881 ppmAverage of 10 samples

2012–2019

4.000 ppm

22.0%

Within Limit

26,302

#47

Granite City

Illinois

0.875 ppmAverage of 8 samples

2012–2019

4.000 ppm

21.9%

Within Limit

33,572

#48

Haverhill

Massachusetts

0.870 ppmAverage of 7 samples

2012–2019

4.000 ppm

21.8%

Within Limit

61,277

#49

Wakefield

Massachusetts

0.873 ppmAverage of 8 samples

2012–2019

4.000 ppm

21.8%

Within Limit

27,090

#50

Cincinnati

Ohio

0.863 ppmAverage of 16 samples

2012–2019

4.000 ppm

21.6%

Within Limit

750,200

#51

Fremont

California

0.862 ppmAverage of 133 samples

2012–2019

4.000 ppm

21.6%

Within Limit

344,000

#52

Hartford

Connecticut

0.862 ppmAverage of 24 samples

2012–2019

4.000 ppm

21.5%

Within Limit

390,887

#53

Fall River

Massachusetts

0.859 ppmAverage of 8 samples

2012–2019

4.000 ppm

21.5%

Within Limit

94,000

#54

Bloomington

Illinois

0.856 ppmAverage of 9 samples

2012–2019

4.000 ppm

21.4%

Within Limit

77,610

#55

Crystal Lake

Illinois

0.857 ppmAverage of 15 samples

2012–2019

4.000 ppm

21.4%

Within Limit

40,661

#56

Nicholasville

Kentucky

0.857 ppmAverage of 27 samples

2012–2019

4.000 ppm

21.4%

Within Limit

35,266

#57

New Haven

Connecticut

0.848 ppmAverage of 82 samples

2012–2019

4.000 ppm

21.2%

Within Limit

418,900

#58

Henderson

Kentucky

0.850 ppmAverage of 15 samples

2012–2019

4.000 ppm

21.2%

Within Limit

31,705

#59

Groton

Connecticut

0.848 ppmAverage of 8 samples

2012–2019

4.000 ppm

21.2%

Within Limit

30,200

#60

Lexington

Kentucky

0.842 ppmAverage of 49 samples

2012–2019

4.000 ppm

21.1%

Within Limit

669,042

#61

Shreveport

Louisiana

0.843 ppmAverage of 9 samples

2012–2019

4.000 ppm

21.1%

Within Limit

192,378

#62

Champaign

Illinois

0.843 ppmAverage of 8 samples

2012–2019

4.000 ppm

21.1%

Within Limit

150,000

#63

Russellville

Arkansas

0.845 ppmAverage of 103 samples

2012–2019

4.000 ppm

21.1%

Within Limit

29,260

#64

Aurora

Illinois

0.840 ppmAverage of 10 samples

2012–2019

4.000 ppm

21.0%

Within Limit

183,000

#65

New Britain

Connecticut

0.841 ppmAverage of 8 samples

2012–2019

4.000 ppm

21.0%

Within Limit

73,534

#66

Marlborough

Massachusetts

0.834 ppmAverage of 5 samples

2012–2019

4.000 ppm

20.9%

Within Limit

41,799

#67

Jacksonville

Arkansas

0.838 ppmAverage of 105 samples

2012–2019

4.000 ppm

20.9%

Within Limit

32,875

#68

Temple Terrace

Florida

0.835 ppmAverage of 47 samples

2012–2019

4.000 ppm

20.9%

Within Limit

31,250

#69

Algonquin

Illinois

0.837 ppmAverage of 9 samples

2012–2019

4.000 ppm

20.9%

Within Limit

30,700

#70

Rexburg

Idaho

0.827 ppmAverage of 9 samples

2012–2019

4.000 ppm

20.7%

Within Limit

40,695

#71

Shelbyville

Kentucky

0.826 ppmAverage of 34 samples

2012–2019

4.000 ppm

20.7%

Within Limit

23,760

#72

Pueblo

Colorado

0.819 ppmAverage of 32 samples

2012–2019

4.000 ppm

20.5%

Within Limit

114,070

#73

Waterbury

Connecticut

0.819 ppmAverage of 8 samples

2012–2019

4.000 ppm

20.5%

Within Limit

107,271

#74

Decatur

Illinois

0.821 ppmAverage of 10 samples

2012–2019

4.000 ppm

20.5%

Within Limit

76,122

#75

Danville

Kentucky

0.819 ppmAverage of 16 samples

2012–2019

4.000 ppm

20.5%

Within Limit

32,600

#76

Fort Thomas

Kentucky

0.816 ppmAverage of 64 samples

2012–2019

4.000 ppm

20.4%

Within Limit

259,949

#77

Cambridge

Massachusetts

0.816 ppmAverage of 6 samples

2012–2019

4.000 ppm

20.4%

Within Limit

118,214

#78

Normal

Illinois

0.814 ppmAverage of 4 samples

2012–2019

4.000 ppm

20.4%

Within Limit

52,736

#79

Louisville

Kentucky

0.814 ppmAverage of 44 samples

2012–2019

4.000 ppm

20.3%

Within Limit

806,997

#80

Waukegan

Illinois

0.812 ppmAverage of 8 samples

2012–2019

4.000 ppm

20.3%

Within Limit

87,149

#81

Castle Rock

Colorado

0.802 ppmAverage of 31 samples

2012–2019

4.000 ppm

20.1%

Within Limit

110,298

#82

Columbus

Indiana

0.805 ppmAverage of 4 samples

2012–2019

4.000 ppm

20.1%

Within Limit

51,122

#83

Milford

Delaware

0.803 ppmAverage of 385 samples

2012–2019

4.000 ppm

20.1%

Within Limit

9,800

#84

Twin Falls

Idaho

0.801 ppmAverage of 7 samples

2012–2019

4.000 ppm

20.0%

Within Limit

56,121

#85

Hialeah

Florida

0.793 ppmAverage of 14 samples

2012–2019

4.000 ppm

19.8%

Within Limit

238,000

#86

Jonesboro

Arkansas

0.791 ppmAverage of 361 samples

2012–2019

4.000 ppm

19.8%

Within Limit

81,888

#87

Georgetown

Kentucky

0.794 ppmAverage of 16 samples

2012–2019

4.000 ppm

19.8%

Within Limit

44,608

#88

Moscow

Idaho

0.793 ppmAverage of 5 samples

2012–2019

4.000 ppm

19.8%

Within Limit

26,000

#89

Bristol

Connecticut

0.788 ppmAverage of 16 samples

2012–2019

4.000 ppm

19.7%

Within Limit

52,079

#90

Santa Maria

California

0.782 ppmAverage of 73 samples

2012–2019

4.000 ppm

19.6%

Within Limit

109,477

#91

Lawrence

Massachusetts

0.786 ppmAverage of 7 samples

2012–2019

4.000 ppm

19.6%

Within Limit

89,143

#92

Paragould

Arkansas

0.783 ppmAverage of 99 samples

2012–2019

4.000 ppm

19.6%

Within Limit

31,188

#93

Sahuarita

Arizona

0.783 ppmAverage of 3 samples

2012–2019

4.000 ppm

19.6%

Within Limit

18,178

#94

Fairfield

California

0.779 ppmAverage of 65 samples

2012–2019

4.000 ppm

19.5%

Within Limit

120,377

#95

Bardstown

Kentucky

0.780 ppmAverage of 14 samples

2012–2019

4.000 ppm

19.5%

Within Limit

31,185

#96

Florence

Arizona

0.780 ppmAverage of 3 samples

2012–2019

4.000 ppm

19.5%

Within Limit

15,900

#97

Houma

Louisiana

0.781 ppmAverage of 7 samples

2012–2019

4.000 ppm

19.5%

Within Limit

11,658

#98

Key West

Florida

0.775 ppmAverage of 123 samples

2012–2019

4.000 ppm

19.4%

Within Limit

86,000

#99

Commerce City

Colorado

0.776 ppmAverage of 264 samples

2012–2019

4.000 ppm

19.4%

Within Limit

75,559

#100

Benton

Arkansas

0.776 ppmAverage of 200 samples

2012–2019

4.000 ppm

19.4%

Within Limit

30,681