EWG's Tap Water Database — 2021 UPDATE


Radium, combined (-226 & -228)

Status: National drinking water standard exists


Radium is a radioactive element that causes bone cancer and other cancers. It can occur naturally in groundwater, and oil and gas extraction activities such as hydraulic fracturing can elevate concentrations. Read More.

Radium releases radioactive particles that harm health in many ways, causing tumors in bone, lungs and other organs; leukemia; and skin and blood damage. Water utilities typically report radium amounts in picocuries per liter (pCi/L), which is a measure of radioactivity in water. The two most common forms of radium are radium-226 and radium-228. They may be reported separately or together.

Federal law allows up to 5 picocuries per liter of combined radium-226 and radium-228 in tap water. Research by the U.S. Geological Survey shows that in some regions of the country, such as the mid-continental region and North Atlantic coastal region, more than 20 percent of sampled wells have radium in levels exceeding the federal drinking water limit. And the legal limit does not equate safety: The EPA estimates that one in every 10,000 people drinking water containing radium at this level would develop cancer over a lifetime.

California set a public health goal much lower than the federal limit – 0.05 picocuries per liter of radium-226 and 0.019 picocuries per liter of radium-228, concentrations that are lower than the detection limit for most water tests.

Click here to read more on radiological contaminants.




states detected


utilities detected

148 million

people served


states over health guideline


utilities over health guideline

146 million

people served over health guideline

Health concerns for radium, combined (-226 & -228)


State and national drinking water standards and health guidelines

EWG Health Guideline 0.05 pCi/L

EWG applied the health guideline of 0.05 pCi/L, defined by the California Office of Environmental Health Hazard Assessment as a public health goal for radium-226, to radium-226 and radium-228 combined. This health guideline protects against cancer.

EPA Maximum Contaminant
Level (MCL) 5 pCi/L

The legal limit for combined radium-226 and radium-228, established in 1976, was based on costs for radium removal, as calculated at the time that the standard was set. This limit does not fully protect against the risk of cancer due to radium exposure.

pCi/L = picocuries per liter

States reporting radium, combined (-226 & -228) in drinking water

State UtilitiesPeople Served UtilitiesPeople Served
New York1,0395,960,9121,0365,965,024
New Jersey3844,994,0323834,992,032
North Carolina6432,482,3456442,505,343
New Mexico4721,862,7375411,931,200
West Virginia3121,082,2263041,104,439
New Hampshire519760,568523760,444
District Of Columbia4664,5723648,882
South Carolina176620,342179613,796
North Dakota241565,840231556,147
Rhode Island19195,03319195,033
South Dakota174188,576174188,576

Filtering technologies that reduce radium, combined (-226 & -228)

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Utilities with the highest amounts of radium, combined (-226 & -228), 2014-2019

UtilityLocationTestsAverage levelPeople served
Patterson Valley Water CompanyRocky Ford, CO5 of 523.16 pCi/L96
South Council Creek 2Austin, TX4 of 421.90 pCi/L111
Eureka Water CompanySwink, CO12 of 1219.63 pCi/L498
Fayette Water CompanyManzanola, CO9 of 919.52 pCi/L75
South Silver Creek I II & IIIAustin, TX24 of 2419.11 pCi/L258
South Swink Water CompanyLa Junta, CO24 of 2417.55 pCi/L607
City of Brady Water System*Brady, TX115 of 11517.34 pCi/L5,371
Valley Water CompanyManzanola, CO22 of 2215.49 pCi/L270
Vroman Water CompanyManzanola, CO13 of 1314.86 pCi/L125
Lakeland ServicesBrady, TX22 of 2212.84 pCi/L51
Buffalo GroveBuffalo Grove, IL1 of 112.83 pCi/L41,266
Live Oak Hills SubdivisionLlano, TX24 of 2412.73 pCi/L65
Peak View Park LlcWoodland Park, CO10 of 1012.63 pCi/L70
May Valley WaWiley, CO75 of 7512.58 pCi/L1,500
Bgwc Peachtree AcresGreenville, SC10 of 1012.40 pCi/L119
Wilmington*Wilmington, IL2 of 211.83 pCi/L5,757
Lakewood Shores Improvement AssociationWilmington, IL2 of 211.83 pCi/L868
GurneeGurnee, IL1 of 111.72 pCi/L31,284
Signal Mountain Ranch Property Owners Water CompanyBeulah, CO11 of 1111.55 pCi/L66
Leadwood PWSLeadwood, MO16 of 1610.53 pCi/L1,252
Downsville Sanitary DistrictDownsville, WI2 of 210.45 pCi/L250
Champion Farms SubdivisionTroy, MO55 of 5510.39 pCi/L30
Cheraw, Town ofCheraw, CO12 of 1210.38 pCi/L254
West Grand Valley WaRocky Ford, CO7 of 710.34 pCi/L100
North Holbrook Water CompanyRocky Ford, CO12 of 1210.33 pCi/L58
Rolling MeadowsRolling Meadows, IL4 of 410.17 pCi/L24,099
Gilford Village Water DistrictGilford, NH1 of 110.00 pCi/L130
Lake Texoma Vfw Post 7873Pottsboro, TX24 of 249.60 pCi/L114
Gator Wilderness Camp SchoolPunta Gorda, FL11 of 119.39 pCi/L44
Monterey Rural Water System Inc.Monterey, LA50 of 599.39 pCi/L5,250
Cady Brook Crossing CondominiumsCharlton, MA2 of 29.37 pCi/L75
Tempe Water Supply Corporation 1Livingston, TX45 of 499.34 pCi/L1,897
Holbrook Center Soft WaLa Junta, CO12 of 129.01 pCi/L51
Ranch Water Service Inc.Kingman, AZ21 of 248.79 pCi/L135
Perry County Public Water Supply District 1Perryville, MO20 of 208.52 pCi/L1,970
Welch Public Works AuthorityWelch, OK21 of 218.47 pCi/L800
Cassandra Water SystemMoriaty, NM21 of 218.38 pCi/L34
Tanglewood Forest SubdivisionLivingston, TX12 of 128.31 pCi/L73
Hillsdale Garden ApartmentsHudson, NY1 of 18.30 pCi/L40
GlenwoodGlenwood, GA6 of 68.27 pCi/L742
WinonaWinona, MN28 of 288.26 pCi/L27,782
Highland CourtHillsborough, TX24 of 248.21 pCi/L90
Diamond Valley AcresSt George, UT3 of 38.10 pCi/L1,340
Big Plains Sw Special Service District - Cedar PointApple Valley, UT9 of 98.04 pCi/L232
Northwoods S/dEatonton, GA7 of 87.90 pCi/L120
Allouez WaterworksGreen Bay, WI2 of 27.89 pCi/L13,932
Rochelle Water Supply CorporationRochelle, TX23 of 247.63 pCi/L372
Jackson, Village ofEmerson, NE3 of 37.61 pCi/L230
Md#07 Marina View HeightsMadera, CA1 of 17.60 pCi/L200
Hillcrest Commons-rear SectionSchenectady, NY1 of 17.60 pCi/L42

* 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 Radium, combined (-226 & -228), but it likely has the contaminant in its water supply.

UtilityLocationTestsAverage levelPeople served
Buffalo GroveBuffalo Grove, IL1 of 112.83 pCi/L41,266
GurneeGurnee, IL1 of 111.72 pCi/L31,284
Rolling MeadowsRolling Meadows, IL4 of 410.17 pCi/L24,099
WinonaWinona, MN28 of 288.26 pCi/L27,782
Allouez WaterworksGreen Bay, WI2 of 27.89 pCi/L13,932
Round Lake Beach*Round Lake Beach, IL1 of 27.49 pCi/L28,845
AndoverAndover, MN28 of 337.15 pCi/L20,485
Bellevue WaterworksGreen Bay, WI1 of 27.08 pCi/L15,365
Delta Charter TownshipOtisville, MI4 of 46.65 pCi/L22,000
Franklin Water UtilityFranklin, WI1 of 16.56 pCi/L22,500
Mount ProspectMount Prospect, IL3 of 36.39 pCi/L41,492
Ashwaubenon Waterworks*Green Bay, WI3 of 36.38 pCi/L17,730
Inver Grove Heights*Inver Grove Heights, MN7 of 76.27 pCi/L34,189
Fort Dodge Water Supply*Fort Dodge, IA30 of 305.79 pCi/L25,206
Waukesha Water UtilityWaukesha, WI126 of 1265.72 pCi/L70,718
OtsegoOtsego, MN38 of 445.50 pCi/L11,500
Sussex Village Hall & Water UtilitySussex, WI88 of 905.31 pCi/L10,573
Kaukauna UtilitiesKaukauna, WI34 of 375.07 pCi/L13,430
North MankatoNorth Mankato, MN14 of 145.00 pCi/L13,462
FaribaultFaribault, MN4 of 44.90 pCi/L23,718
Perdido Bay Water, Sewer and Fire Protection AuthorityElberta, AL7 of 74.86 pCi/L10,824
Marion Municipal Water Department*Marion, IA13 of 134.53 pCi/L34,610
LakevilleLakeville, MN6 of 64.50 pCi/L64,334
Galesburg*Galesburg, IL3 of 34.40 pCi/L31,745
North AuroraNorth Aurora, IL20 of 224.34 pCi/L17,500
De Pere Water DepartmentDe Pere, WI12 of 134.29 pCi/L23,920
StreamwoodStreamwood, IL4 of 44.26 pCi/L40,351
YorkvilleYorkville, IL40 of 404.16 pCi/L18,000
Brookfield Water UtilityBrookfield, WI78 of 784.12 pCi/L29,070
Michigan State UniversityEast Lansing, MI76 of 764.10 pCi/L12,793
Fond Du Lac WaterworksFond Du Lac, WI44 of 654.08 pCi/L42,000
Emerald Coast Utilities Authority*Pensacola, FL15 of 154.07 pCi/L255,884
Fayetteville*Fayetteville, GA2 of 24.05 pCi/L15,281
Milan Water DepartmentMilan, TN1 of 14.01 pCi/L10,785
Burnsville*Burnsville, MN2 of 24.00 pCi/L61,747
City of Laurinburg*Laurinburg, NC2 of 23.90 pCi/L18,288
Waupun UtilitiesWaupun, WI17 of 173.87 pCi/L11,340
South Saint PaulSouth St. Paul, MN17 of 183.86 pCi/L20,400
Manchester Twp Water Utility - Eastern*Manchester Twp, NJ14 of 163.84 pCi/L21,200
Darboy Sanitary District 1Appleton, WI18 of 193.82 pCi/L12,000
PeruPeru, IL10 of 103.79 pCi/L10,300
Epcor Water - Anthem*Youngtown, AZ2 of 23.75 pCi/L25,302
Naval Air Station Pensacola / Corry StationNas Pensacola, FL22 of 223.74 pCi/L22,600
Manasquan Water DepartmeManasquan, NJ2 of 23.73 pCi/L14,000
City of ColumbusColumbus, NE3 of 33.71 pCi/L22,797
Aquarion Water Company of Connecticut - Valley System*Bridgeport, CT2 of 23.70 pCi/L13,080
MinookaMinooka, IL26 of 263.70 pCi/L11,307
MorrisMorris, IL6 of 63.69 pCi/L13,926
Howard WaterworksGreen Bay, WI10 of 113.67 pCi/L18,900
Barnegat Twp Water SewerBarnegat, NJ12 of 123.66 pCi/L20,000

* 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 Radium, combined (-226 & -228), but it likely has the contaminant in its water supply.