EWG's Tap Water Database — 2019 UPDATE



Status: National drinking water standard exists


Thalium is a naturally occurring metal released into the environment from metal smelting and coal burning. Exposure to too much thalium can cause hair loss, liver damage, reduced sperm motility and nervous system impairment.




states detected


utilities detected

11 million

people served


states over health guideline


utilities over health guideline

2.3 million

people served over health guideline

Health concerns for thallium

Hair loss

Harm to the liver

Harm to the central nervous system

Harm to the brain and nervous system

Harm to the male reproductive system

State and national drinking water standards and health guidelines

EWG Health Guideline 0.1 ppb

The EWG Health Guideline of 0.1 ppb for thallium was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to internal organs.

EPA Maximum Contaminant
Level (MCL) 2 ppb

The legal limit for thallium, established in 1992, was based on analytical detection limits at the time that the standard was set.

ppb = parts per billion

States reporting thallium in drinking water

State UtilitiesPeople Served UtilitiesPeople Served
North Carolina9558,445171,425,776
New Jersey33305,580971,184,018
New York22154,94154789,942
South Carolina512,262621,332
New Mexico21,25321,253
South Dakota12001200
West Virginia00160
New Hampshire127127

Filtering technologies that reduce thallium

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Reverse Osmosis

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Ion Exchange

Utilities with the highest amounts of thallium, 2015-2017

UtilityLocationTestsAverage levelPeople served
Alpine Acres Community AssociationLeavenworth, WA2 of 23.10 ppb46
Kathleen Oaks Mobile Home ParkLakeland, FL1 of 13.00 ppb35
Davenport Mob EstHaines City, FL1 of 13.00 ppb390
Sandy Hook Water DistrictSandy Hook, KY1 of 12.40 ppb3,528
Cedar Acres Mobile Home ParkNassau, NY1 of 12.00 ppb276
White Haven CenterWhite Haven, PA1 of 12.00 ppb659
Yuma West Mobile Home ParkYuma, AZ1 of 11.90 ppb30
Independence Municipal Utilities Authority HighlndGreat Meadows, NJ1 of 11.71 ppb350
Arlinghaus PropertyBurlington, KY1 of 11.70 ppb49
Hidden Village Condo AssociationHambrug, NJ1 of 11.70 ppb175
Lake Ridge Water SystemAustin, TX1 of 11.70 ppb966
Lake Stockholm Inc.Stockholm, NJ1 of 11.66 ppb300
Independence Municipal Utilities Authority Valley ViewGreat Meadows, NJ1 of 11.56 ppb110
Rough & Ready Mobilehome VillageChowchilla, CA1 of 11.53 ppb200
Freedom Water & Sewer DistrThayne, WY1 of 11.50 ppb300
Sunnyside EstatesBeaver Dam, WI2 of 21.44 ppb130
Pioneer Estates Of DelavanDelavan, WI2 of 21.41 ppb400
Caernarvon Township AuthorityMorgantown, PA3 of 31.33 ppb4,139
Clinton WaterworksClinton, WI12 of 121.31 ppb2,119
PeruPeru, IL1 of 21.30 ppb11,000
Toppenish Water DepartmentToppenish, WA4 of 51.26 ppb8,950
Canyon Hills Mutual Domestic Water Consumers AssociationAlamogordo, NM2 of 21.18 ppb53
Concordia Waterworks District 1Ferriday, LA2 of 121.17 ppb6,921
Pine Country EstatesKnightdale, NC1 of 11.16 ppb44
Palms River ResortHemet, CA1 of 21.15 ppb200
Rivermeadows Water DistrictJackson, WY1 of 31.13 ppb100
Hopatcong Water DepartmentHopatcong, NJ7 of 71.13 ppb7,224
Hunt Farms S/dGarner, NC1 of 11.12 ppb88
Yellowstone Np Old FaithfulYellowstone National Park, WY2 of 41.10 ppb150
Inwood EstatesPlymouth, IN1 of 11.10 ppb20
Fayson Lakes Water Company Inc.Kinnelon, NJ1 of 11.09 ppb3,010
Hillside Estates At FranklinFranklin, NJ1 of 11.09 ppb300
Birchwood TerraceWyoming, MN1 of 11.05 ppb200
Awo&m - Picatinny ArsenalWharton, NJ1 of 11.01 ppb6,011
Regal Mobile EstatesYakima, WA1 of 11.000 ppb127
Gulf Correctional InstitutionWewahitchka, FL1 of 11.000 ppb3,500
Martins Community Lp Mobile Home ParkCochranville, PA1 of 11.000 ppb180
Cheswick Borough Water DepartmentCheswick, PA1 of 11.000 ppb1,769
Bingen Water DepartmentBingen, WA1 of 11.000 ppb735
Melody Lake AcresMonticello, NY1 of 11.000 ppb150
Wrentham Developmental CenterWrentham, MA1 of 11.000 ppb1,309
De Chenne Water SystemEast Wenatchee, WA1 of 11.000 ppb34
MagnoliaMagnolia, IL1 of 21.000 ppb279
Twin Pines Health Care CenterWest Grove, PA1 of 11.000 ppb120
Riverbend EstatesAmerican Falls, ID1 of 11.000 ppb92
Arbor Arms ApartmentsPoughkeepsie, NY1 of 11.000 ppb70
Dillon FarmsMonticello, NY1 of 11.000 ppb50
Snell Isle Realty LLCAuburndale, FL1 of 11.000 ppb200
Harmar Township Muni Authority*Cheswick, PA1 of 11.000 ppb2,921
LebanonLebanon, MO4 of 160.998 ppb14,300

* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Thallium, but it likely has the contaminant in its water supply.

UtilityLocationTestsAverage levelPeople served
PeruPeru, IL1 of 21.30 ppb11,000
LebanonLebanon, MO4 of 160.998 ppb14,300
Eagle Mountain CityEagle Mountain, UT24 of 380.774 ppb24,000
Winter Garden Water Department*Winter Garden, FL3 of 30.567 ppb69,738
City of GrandviewGrandview, WA3 of 30.567 ppb10,922
City of Moses LakeMoses Lake, WA5 of 50.520 ppb22,930
City of Mount DoraMount Dora, FL2 of 20.450 ppb29,996
City of Yakima Water Division*Yakima, WA7 of 70.429 ppb65,238
Atascosa Rural WSCAtascosa, TX2 of 40.413 ppb10,482
Rehoboth DistrictDover, DE2 of 130.354 ppb32,700
Gardner Water DepartmentGardner, MA1 of 40.350 ppb19,133
Windermere CommunityPflugerville, TX4 of 60.337 ppb20,091
City of Havre De Grace*Havre De Grace, MD1 of 30.333 ppb14,000
City of Fort StocktonFort Stockton, TX1 of 20.330 ppb12,502
Onalaska WaterworksOnalaska, WI3 of 50.320 ppb18,000
South Brunswick Twp W*Rocky Hill, NJ2 of 100.314 ppb45,450
Nob Hill Water AssociationYakima, WA3 of 30.300 ppb28,827
City of Show LowShow Low, AZ2 of 90.256 ppb17,139
Paw Penn DistrictBirdsboro, PA1 of 80.238 ppb29,525
Lake Asbury WTPOrange Park, FL1 of 10.200 ppb10,294
Fair Lawn Water DepartmentFair Lawn Boro, NJ3 of 100.192 ppb31,000
Town of Hempstead Water DepartmentEast Meadow, NY9 of 660.176 ppb110,000
Ogdensburg CityOgdensburg, NY1 of 30.173 ppb11,128
Greenup Water System*Greenup, KY1 of 30.167 ppb12,193
Jackson County Water Association*Tyner, KY1 of 30.167 ppb13,629
City of Raleigh*Raleigh, NC1 of 60.167 ppb521,839
Williamson Town WD*Williamson, NY1 of 30.167 ppb12,000
Lackland Air Force BaseJbsa Lackland, TX1 of 50.162 ppb20,907
Lacey Twp MUAForked River, NJ1 of 30.156 ppb26,240
Mcguire Air Force BaseJoint Base Mdl, NJ2 of 60.150 ppb12,227
Whitman Water System*Whitman, MA1 of 70.143 ppb14,574
Brockton Water Commission*Brockton, MA1 of 70.143 ppb93,810
Manitowoc Waterworks*Manitowoc, WI1 of 40.141 ppb34,500
Grafton WaterworksGrafton, WI5 of 50.138 ppb11,745
Tri SUDMount Pleasant, TX1 of 30.120 ppb16,734
Minden Water SystemMinden, LA2 of 200.120 ppb16,950
City of Mount Pleasant*Mount Pleasant, TX1 of 30.120 ppb16,113
City of Rio Grande City*Rio Grande City, TX1 of 60.118 ppb17,901
Garfield Water DepartmentGarfield, NJ1 of 30.113 ppb30,487
Perth Amboy Water DepartmentPerth Amboy, NJ1 of 30.107 ppb52,328
Clermont East Water SystemClermont, FL2 of 20.1000 ppb33,162
Platteville WaterworksPlatteville, WI1 of 20.1000 ppb12,268
City of Temple Terrace UtilityTemple Terrace, FL1 of 20.1000 ppb31,062
University of South FloridaTampa, FL1 of 10.1000 ppb46,237
Pike County Water Authority*Troy, AL3 of 70.0986 ppb10,590
New York American Water - MerrickMerrick, NY38 of 1320.0974 ppb177,000
City of San LuisSan Luis, AZ6 of 60.0933 ppb27,800
City of Mansfield*Mansfield, TX1 of 30.0900 ppb68,612
Miramar (East & West) PlantsMiramar, FL1 of 60.0833 ppb128,729
HempsteadHempstead, NY5 of 250.0808 ppb56,000

* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Thallium, but it likely has the contaminant in its water supply.