EWG's Tap Water Database — 2021 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

9.8 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
New York28304,102601,267,995
New Jersey37,95612205,867
West Virginia812,2531230,629
North Carolina33,515422,057
Rhode Island00210,199
South Carolina58,11358,113
New Mexico32,56232,562
New Hampshire22902290
South Dakota12001200

Filtering technologies that reduce thallium

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Reverse Osmosis

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Ion Exchange

Utilities with the highest amounts of thallium, 2017-2019

UtilityLocationTestsAverage levelPeople served
Alpine Acres Community AssociationLeavenworth, WA3 of 32.30 ppb46
Butterfield Common Senior HousingKeene, VT1 of 32.00 ppb105
Rincon Water Consumers Co-opHatch, NM2 of 51.97 ppb580
Yuma West Mobile Home ParkYuma, AZ1 of 11.90 ppb30
South Hills Water Users Association Inc.Yakima, WA1 of 11.90 ppb135
Lake Ridge Water SystemAustin, TX2 of 21.75 ppb1,041
Fordair Water Co-op Inc.Coulee City, WA1 of 11.70 ppb34
Kathleen Oaks Mobile Home ParkLakeland, FL1 of 21.50 ppb35
Freedom W&s DistrictGrover, WY1 of 11.50 ppb300
Davenport Mob EstHaines City, FL1 of 21.50 ppb390
Cedar PointeRockville, VA1 of 21.38 ppb145
East Ridge ParkYakima, WA1 of 21.30 ppb150
Kake Municipal WaterKake, AK1 of 11.30 ppb415
Tampico Drive Well Owners AssociationYakima, WA2 of 31.27 ppb42
Clinton WaterworksClinton, WI25 of 251.25 ppb2,119
Valley Maint Corporation No. 2Divide, CO1 of 11.20 ppb55
Loch Laurel Mobile Home ParkValdosta, GA1 of 21.20 ppb62
Canyon Hills Mutual Domestic Water Consumers AssociationAlamogordo, NM2 of 21.18 ppb53
Surrey Village Water Company Inc.Red Bluff, CA2 of 41.15 ppb145
Gleed Mobile EstatesYakima, WA2 of 21.15 ppb76
Rivermeadows Water DistrictJackson, WY1 of 31.13 ppb100
Bauers Landing LodgeOrondo, WA1 of 11.10 ppb124
Inwood EstatesPlymouth, IN1 of 11.10 ppb50
Ruth Water DistrictMcgill, NV1 of 11.10 ppb470
Brown Taylor Water Company Inc.Selah, WA1 of 11.10 ppb30
MO American Stonebridge VillageBranson, MO4 of 81.03 ppb1,875
Shiloh Waterworks DistrictBienville, LA2 of 41.000 ppb153
Cedar Acres Mobile Home ParkChatham, NY1 of 21.000 ppb276
Bingen Water DepartmentBingen, WA1 of 11.000 ppb735
Bryceland Water System*Bienville, LA2 of 41.000 ppb243
Southview WiseNewburg, MD1 of 21.000 ppb61
White Haven CenterWhite Haven, PA1 of 21.000 ppb620
Peshastin Domestic Water AssociationPeshastin, WA1 of 11.000 ppb108
De Chenne Water SystemEast Wenatchee, WA1 of 11.000 ppb34
Arbor Arms ApartmentsPoughkeepsie, NY1 of 11.000 ppb70
Riverbend EstatesAmerican Falls, ID2 of 21.000 ppb92
Sundquist Twh-terrace HeightsYakima, WA2 of 20.950 ppb96
Birchwood TerraceMaplewood, MN3 of 40.923 ppb125
Twin W OrchardsOrondo, WA1 of 10.900 ppb103
Moxie Community LlcPort Orchard, WA1 of 10.900 ppb114
Shady Oaks Rv and Mobile Home ParkCross City, FL1 of 20.900 ppb75
Yoder, Town OfYoder, WY1 of 10.900 ppb158
Broken Wrench LlcCasper, WY1 of 30.900 ppb30
Hawks Meadow Water SystemEast Wenatchee, WA1 of 10.900 ppb14
Bethel Ash Water Supply Corporation Lowe PlantAthens, TX1 of 20.900 ppb684
Quail Run Mobile Home ParkEast Wenatchee, WA1 of 10.900 ppb165
Independence Municipal Utilities Authority HighlndHaworth, NJ1 of 20.855 ppb350
Hidden Village Condo AssociationHambrug, NJ1 of 20.850 ppb175
Arlinghaus PropertyBurlington, KY1 of 20.850 ppb49
City Of West PointRadcliff, KY1 of 20.850 ppb975

* 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
Atascosa Rural WSCAtascosa, TX5 of 90.698 ppb11,007
LebanonLebanon, MO4 of 230.694 ppb14,709
PeruPeru, IL1 of 40.650 ppb10,300
City of GrandviewGrandview, WA9 of 100.630 ppb11,010
Eagle Mountain CityEagle Mountain, UT38 of 680.624 ppb36,000
City of Moses LakeMoses Lake, WA15 of 180.533 ppb22,930
City of Yakima Water DivisionYakima, WA9 of 90.411 ppb72,806
Sandusky City*Sandusky, OH1 of 110.400 ppb25,793
Nob Hill Water AssociationYakima, WA4 of 40.375 ppb29,685
West Kern Water DistrictTaft, CA2 of 240.375 ppb21,181
City of KearneyKearney, NE1 of 30.360 ppb30,919
Southwest/Polk County UtilityLakeland, FL3 of 100.350 ppb39,209
Winter Garden Water Department*Winter Garden, FL4 of 60.300 ppb74,326
South Brunswick Twp W*Rocky Hill, NJ3 of 190.294 ppb45,450
Consolidated Mutual Maple Grove*Lakewood, CO1 of 60.283 ppb24,135
Little Thompson WD*Berthoud, CO1 of 60.283 ppb20,076
Windermere CommunityPflugerville, TX6 of 110.271 ppb20,091
City of Mount DoraMount Dora, FL3 of 40.250 ppb34,224
Del Rio Utilities Commission*Del Rio, TX1 of 60.250 ppb36,506
Rehoboth DistrictDover, DE2 of 190.242 ppb32,700
Huber Heights Public Water SystemHuber Heights, OH1 of 40.230 ppb38,278
City of Fort StocktonFort Stockton, TX1 of 30.220 ppb12,502
Onalaska WaterworksOnalaska, WI4 of 90.211 ppb18,000
Ocean PinesBerlin, MD1 of 100.180 ppb11,890
Gardner Water DepartmentGardner, MA1 of 80.175 ppb19,314
City of Havre De Grace*Havre De Grace, MD1 of 60.167 ppb14,000
Dover Water Commission*Dover, NJ1 of 40.161 ppb27,806
Central Elmore Water Authority*Wetumpka, AL1 of 70.157 ppb36,900
Hawthorne Water Department*Hawthorne Boro, NJ2 of 80.151 ppb21,006
Edwardsville Water Corporation*Georgetown, IN1 of 20.150 ppb10,200
Mcguire Air Force BaseJoint Base Mdl, NJ2 of 60.150 ppb12,227
Howard WaterworksGreen Bay, WI2 of 50.144 ppb18,900
City of West SacramentoSacramento, CA1 of 50.138 ppb46,500
Fair Lawn Water DepartmentFair Lawn Boro, NJ3 of 140.137 ppb31,000
Truckee Meadows Water Authority*Reno, NV7 of 1100.130 ppb311,932
Sun Valley GidSun Valley, NV7 of 1100.130 ppb17,000
Placer County Water Agency - Foothill*Auburn, CA3 of 180.128 ppb78,583
Lake Utility Services Inc NorthClermont, FL1 of 160.125 ppb21,518
South Orange Water DepartmentSouth Orange, NJ1 of 50.123 ppb16,964
Beauregard Water AuthorityOpelika, AL1 of 60.117 ppb11,178
Lacey Twp MUAForked River, NJ1 of 40.117 ppb26,240
Gadsden County Regional WSQuincy, FL6 of 150.113 ppb12,371
Paw Penn DistrictBirdsboro, PA1 of 170.112 ppb28,508
Park ForestPark Forest, IL1 of 50.110 ppb21,975
City of Show LowShow Low, AZ2 of 210.110 ppb17,139
Stoughton WaterworksStoughton, WI4 of 80.108 ppb12,698
Altamonte Springs Water Department*Altamonte Springs, FL1 of 40.1000 ppb55,576
City of LongwoodLongwood, FL2 of 40.1000 ppb20,332
Lake Asbury WTPOrange Park, FL1 of 20.1000 ppb10,294
Silver Springs Shores*Ocala, FL1 of 100.1000 ppb19,569

* 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.