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EWG's Tap Water Database

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All Contaminants

Every contaminant detected nationwide is listed below. Use the search bar to find a specific contaminant.

Contaminant*People served# of states
where detected
#
1,1,1-Trichloroethane2,581,49015
1,1,2-Trichloroethane47,7174
1,1-Dichloroethane*16,821,21339
1,1-Dichloroethylene3,978,56023
1,2,3-Trichlorobenzene361
1,2,3-Trichloropropane*16,878,38221
1,2,3-trimethylbenzene (hemellitol)10,3881
1,2,4-Trichlorobenzene31,3936
1,2,4-Trimethylbenzene314,55918
1,2-Dibromo-3-chloropropane (DBCP)4,486,5588
1,2-Dichloroethane562,22318
1,2-Dichloroethylene, cis-6,140,91631
1,2-Dichloroethylene, trans-499,41410
1,2-Dichloropropane550,2408
1,3,5-Trimethylbenzene173,22010
1,3-Butadiene*429,9191
1,3-Dichloropropane8,0111
1,4-Dioxane*88,422,06845
17-beta-Estradiol*265,3601
2,4-D4,346,19514
2,4-DB1,2021
2-Furancarboxyaldehyde766,1681
2-Methylbutane28,0021
3-Hydroxycarbofuran5771
4-Androstene-3,17-dione*20,169,68025
A
Acetochlor371,7233
Acetone6,360,62511
Alachlor (Lasso)36,0314
Aldicarb sulfoxide5242
Aldrin961
Aluminum65,967,55130
Antimony11,914,68631
Arsenic70,496,55748
Asbestos1,264,5109
Atrazine29,860,22328
B
Barium153,678,01449
Bentazon (Basagran)1,2021
Benzaldehyde1,8781
Benzene496,37916
Benzo[a]pyrene1,974,63312
Beryllium1,600,12421
bis(2-chloroethyl) ether494,9364
Bromacil149,9692
Bromate31,176,03828
Bromide26,637,30319
Bromochloroacetic acid49,482,39818
Bromochloromethane*33,288,89642
Bromodichloroacetic acid3,776,1023
Bromodichloromethane219,622,56548
Bromoform124,938,99747
Bromomethane*5,225,58432
Butachlor1101
Butane44,1751
Butyl benzyl phthalate352,8803
Butyl citrate135,4891
C
Cadmium2,453,58228
Caffeine816,8851
Carbofuran256,7215
Carbon tetrachloride1,111,29420
Chlorate*207,949,91350
Chlordane2,627,6267
Chlorite25,336,67328
Chlorodibromoacetic acid1,237,9131
Chlorodifluoromethane*29,025,32238
Chloroethane104,2527
Chloroform220,552,41346
Chloromethane*19,252,63340
Chlorotoluene, o-1332
Chlorotoluene, p-841
Chromium (hexavalent)*249,646,74750
Chromium (total)128,332,24750
Cobalt*16,439,19834
Cresol, p-45,0601
Cyanide22,948,80329
Cyclohexane9,6571
D
Dacthal264,5001
Dalapon4,056,14812
DCPA di-acid degradate1,312,4401
DCPA mono- and di-acid degradates2,351,9965
Desethylatrazine19,3361
Desisopropylatrazine249,7422
Di(2-ethylhexyl) adipate770,67910
Di(2-ethylhexyl) phthalate12,918,84433
Di-n-butyl phthalate371,2179
Dibromoacetic acid119,792,97643
Dibromochloromethane198,918,47748
Dibromomethane1,100,6747
Dicamba1,9502
Dichloroacetic acid169,886,38644
Dichlorobenzene, m-1261
Dichlorobenzene, o-9,2082
Dichlorobenzene, p-521,01013
Dichlorodifluoromethane2,473,6736
Dichlorofluoromethane45,5051
Dichloromethane (methylene chloride)807,76721
Dichlorprop4371
Dieldrin397,2905
Diethyl phthalate6501
Diisobutyl phthalate60,9081
Dinoseb52,3846
Diquat1,211,6043
E
Endothall6,6562
Endrin66,7732
Estriol*18,1992
Ethinyl estradiol*3,286,5014
Ethyl ether1,2271
Ethylbenzene1,773,80142
Ethylene dibromide780,66013
F
Fluoranthene55,8631
Fluoride208,632,09850
Formaldehyde680,3111
G
Germanium9,2142
Glyphosate8,6612
H
Haloacetic acids (HAA5)258,362,19650
Heptachlor24,7392
Heptachlor epoxide843,9786
Hexachlorobenzene (HCB)65,9941
Hexachlorocyclopentadiene912,30713
Hexadecanoic acid7,496,5671
Hydrogen sulfide8,0691
I
Iodine-131*38,7541
Iodomethane301
Isobutane35,8221
Isopropyl alcohol23,7941
Isopropyl ether741
Isopropylbenzene11,8044
Isopropyltoluene, p-1,7852
L
Lindane171,3173
Lithium3,594,5573
M
Manganese78,301,93947
Mercury (inorganic)2,509,75926
Methane8501
Methomyl5771
Methoxychlor1,5311
Methyl ethyl ketone908,2435
Methyl isobutyl ketone3,343,6287
Methylcyclohexane5,6491
Metolachlor5,108,11712
Metribuzin187,1112
Microcystin-ADDA251,9381
Molybdenum*156,023,46150
Monobromoacetic acid57,361,85633
Monochloroacetic acid93,026,84240
Monochlorobenzene (chlorobenzene)120,4389
MTBE2,518,31522
N
n-Butylbenzene841
N-Nitrosodi-N-butylamine261,2911
N-Nitrosodimethylamine (NDMA)3,800,3412
n-Propylbenzene264,41516
Naphthalene26,74910
Nitrate217,819,89749
Nitrate & nitrite140,452,43545
Nitrite23,767,46233
O
Octadecanoic acid1,062,0051
Oxamyl (Vydate)1,7122
P
Paraquat1,054,6511
Pentachlorophenol318,01710
Pentane2,0741
Perchlorate7,430,9894
Perfluorobutane sulfonate (PFBS)*336,3204
Perfluoroheptanoic acid (PFHPA)*8,877,51723
Perfluorohexane sulfonate (PFHXS)*5,495,27923
Perfluorononanoic acid (PFNA)*553,3128
Perfluorooctane sulfonate (PFOS)*10,500,84826
Perfluorooctanoic acid (PFOA)*7,535,21927
Phenanthrene145,2722
Phenols3,1501
Picloram228,01012
Polychlorinated biphenyls (PCBs)27,7412
Potassium-40*128,5521
R
Radium, combined (-226 & -228)*92,993,21139
Radium-226*115,851,64548
Radium-228*126,313,10847
Radon*13,539,52922
S
sec-Butylbenzene52,9243
Selenium33,533,38245
Silver2,726,58013
Simazine13,409,42016
Strontium*259,992,70650
Strontium-90*5,240,7999
Styrene131,64015
T
tert-Butyl alcohol865,9332
Testosterone*19,510,56823
Tetrachloroethylene (perchloroethylene)18,967,24844
Tetradecanoic acid192,8191
Tetrahydrofuran169,2754
Thallium1,587,94523
Toluene1,945,37738
Total trihalomethanes (TTHMs)284,034,95150
Toxaphene301
Tribromoacetic acid301,7581
Trichloroacetic acid160,982,97843
Trichloroethylene16,430,86439
Trichlorofluoromethane4,542,9146
Trichlorotrifluoroethane676,2813
Tritium*9,157,13512
U
Uranium, combined (pCi/L)*80,688,80946
V
Vanadium*211,193,93050
Vinyl chloride435,27916
X
Xylene, m-200,7146
Xylene, m- and p-1,059,17816
Xylene, o-1,189,41924
Xylene, p-27,5586
Xylenes (total)11,240,66741

* States and population affected are for 2015 except those chemicals marked with an asterisk. For these chemicals, states and population affected are from 2010-2015. These chemicals were detected under the EPA's Unregulated Contaminant Monitoring Rule (UCMR 3) program or are radiological contaminants.