EWG's Tap Water Database — 2021 UPDATE



Status: National drinking water standard exists


Atrazine is a herbicide commonly detected in drinking water that comes from cornfield and other agricultural runoff. It is a hormone disrupter that harms the male and female reproductive systems of people and wildlife. Read More.

Federal laws allow up to 3 parts per billion of atrazine in treated tap water. Water suppliers average atrazine measurements collected over a year, which means that the reported values underestimate intense spikes of elevated exposures during the periods in late spring and early summer when atrazine is applied in large amounts on farm fields.

Human epidemiological studies suggest that federal standards for atrazine are insufficient to protect public health. In 1999 the California Office of Environmental Health Hazard Assessment set a public health goal of 0.15 parts per billion for atrazine in drinking water, based on a study finding increased rates of breast cancer in rats exposed to the chemical. California’s legal maximum for atrazine in tap water is 1 ppb.

Click here to read more about atrazine.




states detected


utilities detected

43 million

people served


states over health guideline


utilities over health guideline

19 million

people served over health guideline

Health concerns for atrazine

Harm to the developing fetus

Hormone disruption

Harm to the reproductive system

Changes in the nervous system

Changes in brain and behavior


State and national drinking water standards and health guidelines

EWG Health Guideline 0.1 ppb

The EWG Health Guideline of 0.1 ppb for atrazine was defined by EWG based on epidemiological studies of human exposure to atrazine in drinking water.. This health guideline protects against harm to the developing fetus, harm to the reproductive system and hormone disruption.

EPA Maximum Contaminant
Level (MCL) 3 ppb

The legal limit for atrazine, established in 1991, was based on a toxicity study in laboratory animals conducted in the 1980s. This limit does not fully protect against harm to the reproductive system, harm to the developing fetus, and hormone disruption.

ppb = parts per billion

States reporting atrazine in drinking water

State UtilitiesPeople Served UtilitiesPeople Served
North Carolina31478,431701,665,442
South Carolina7240,7667240,766
New Mexico2398552,435
South Dakota1929,7221929,722
New York00923,879
West Virginia00822,144
Rhode Island00119,354

Filtering technologies that reduce atrazine

carbon filter icon

Activated Carbon

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Reverse Osmosis

Utilities with the highest amounts of atrazine, 2017-2019

UtilityLocationTestsAverage levelPeople served
Linn County Rural Water District 2*Mound City, KS5 of 82.17 ppb1,960
Mound City, City ofMound City, KS5 of 82.17 ppb686
Public Wholesale WSD 13*Mound City, KS5 of 82.17 ppb1
Linn County Rural Water District 1La Cygne, KS5 of 82.17 ppb1,200
Hume PWSHume, MO5 of 82.17 ppb336
Parker, City ofParker, KS5 of 82.17 ppb267
Blue Mound, City ofBlue Mound, KS5 of 82.17 ppb273
Howard, City of*Howard, KS10 of 132.16 ppb602
Elk County Rural Water District 2Howard, KS10 of 132.16 ppb206
Neosho County Rural Water District 1cErie, KS9 of 122.07 ppb670
Erie, City of*Erie, KS9 of 122.07 ppb1,085
Great Plains Development AuthorityParsons, KS12 of 181.87 ppb182
Richmond, City ofRichmond, KS7 of 71.82 ppb458
Russell, City ofRussell, KS10 of 171.81 ppb4,463
Oswego, City of*Oswego, KS13 of 221.65 ppb1,698
Labette County Rural Water District 1cOswego, KS13 of 221.65 ppb285
Mitchell County Rural Water District 1Beloit, KS16 of 161.56 ppb345
Beloit, City of*Beloit, KS16 of 161.56 ppb3,726
Anderson County Rural Water District 1Garnett, KS11 of 221.44 ppb37
Garnett, City of*Garnett, KS11 of 221.44 ppb3,262
Carbondale, City of*Carbondale, KS9 of 121.37 ppb1,377
Udall, City ofUdall, KS1 of 31.37 ppb714
Valley Falls, City ofValley Falls, KS7 of 81.33 ppb1,129
Hunter, City ofHunter, KS7 of 71.26 ppb56
Mitchell County Rural Water District 3*Beloit, KS7 of 71.26 ppb2,048
Tipton, City ofTipton, KS7 of 71.26 ppb198
Mitchell County Rural Water District 2*Glen Elder, KS7 of 71.26 ppb1,291
Franklin County Rural Water District 6*Rantoul, KS7 of 81.24 ppb2,960
Lane, City ofLane, KS7 of 81.24 ppb226
Nodaway County Public Water Supply District 1*Maryville, MO24 of 251.21 ppb6,428
Maryville*Maryville, MO24 of 251.21 ppb11,972
Concordia PWS*Concordia, MO23 of 261.20 ppb2,500
Emma PWS*Emma, MO23 of 261.20 ppb205
Allen County Rural Water District 13Chanute, KS9 of 111.14 ppb100
Chanute, City of*Chanute, KS9 of 111.14 ppb9,018
Chetopa, City ofChetopa, KS7 of 131.14 ppb1,035
Milford, City ofMilford, KS1 of 31.10 ppb521
Geary County Rural Water District 4*Milford, KS1 of 31.10 ppb450
Franklin County Rural Water District 2Ottawa, KS6 of 61.09 ppb400
City of Ottawa*Ottawa, KS6 of 61.09 ppb12,267
Princeton, City of*Princeton, KS6 of 61.09 ppb271
Baxter Springs, City of*Baxter Springs, KS1 of 121.08 ppb3,944
Labette County Rural Water District 6Coffeyville, KS7 of 101.08 ppb1,550
Dearing, City of*Dearing, KS7 of 101.08 ppb386
Nowata County Rural Water District #7South Coffeyville, OK7 of 101.08 ppb1,050
South CoffeyvilleSouth Coffeyville, OK7 of 101.08 ppb790
Montgomery County Rural Water District 14Coffeyville, KS7 of 101.08 ppb330
Coffeyville, City of*Coffeyville, KS7 of 101.08 ppb9,366
Montgomery County Rural Water District 2c ASouth Coffeyville, KS7 of 101.08 ppb1,113
Osawatomie, City of*Osawatomie, KS4 of 61.07 ppb4,266

* 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 Atrazine, but it likely has the contaminant in its water supply.

UtilityLocationTestsAverage levelPeople served
Maryville*Maryville, MO24 of 251.21 ppb11,972
City of Ottawa*Ottawa, KS6 of 61.09 ppb12,267
West Warren-Viola U. D.Morrison, TN6 of 151.02 ppb16,179
City of GardnerGardner, KS7 of 80.965 ppb21,871
Leavenworth Water Department*Leavenworth, KS6 of 120.898 ppb36,062
City of Atchison*Atchison, KS7 of 190.803 ppb10,636
City of Topeka*Topeka, KS85 of 880.626 ppb165,000
Aqua Ohio - MarionMarion, OH12 of 270.621 ppb41,925
Murphysboro*Murphysboro, IL26 of 260.600 ppb10,941
Aqua Ohio - TiffinTiffin, OH18 of 280.558 ppb17,963
Springfield Water System*Springfield, TN7 of 230.552 ppb40,516
Newark City PWSNewark, OH12 of 320.547 ppb47,573
City of Olathe*Olathe, KS6 of 60.535 ppb139,605
Aqua Illinois-Vermilion County*Kankakee, IL3 of 80.495 ppb38,000
Ottumwa Water Works*Ottumwa, IA4 of 60.458 ppb25,023
Delaware City PWSDelaware, OH10 of 240.435 ppb34,982
Jackson County PWSD1Grandview, MO1 of 10.430 ppb25,000
Lafourche Water District 1Lockport, LA20 of 580.424 ppb78,760
Lewisburg Water System*Lewsiburg, TN7 of 90.403 ppb19,530
Hardin County Water District #1*Radcliff, KY2 of 120.400 ppb27,033
Fort Leavenworth American Water Ent IncFort Leavenworth, KS1 of 20.380 ppb12,934
Thomas Hill PWSD 1*Moberly, MO12 of 240.378 ppb10,315
Del-Co Water Company Inc.*Delaware, OH41 of 430.376 ppb141,407
City of Midlothian*Midlothian, TX15 of 170.332 ppb16,728
City of Junction City*Junction City, KS2 of 20.330 ppb22,120
Shelbyville Water & Sewer Commission*Shelbyville, KY12 of 240.329 ppb23,760
Citizens Water - Indianapolis*Indianapolis, IN390 of 7490.305 ppb825,173
University Water SystemIowa City, IA2 of 80.300 ppb26,684
Mattoon*Mattoon, IL9 of 230.287 ppb19,000
Indiana American Water - MuncieGreenwood, IN13 of 250.284 ppb65,618
Pulaski Water System*Pulaski, TN5 of 100.278 ppb10,709
Speedway Water WorksSpeedway, IN11 of 230.277 ppb12,140
Pennsylvania American Water Company - Indiana DIndiana, PA6 of 120.275 ppb22,360
Piqua City PWSPiqua, OH13 of 360.271 ppb20,522
Aqua Pa Shenango Valley WTP*Sharon, PA4 of 80.270 ppb48,000
Fremont CityFremont, OH21 of 240.260 ppb16,677
Iowa-American Water Company - DavenportDavenport, IA9 of 100.260 ppb137,201
Rathbun Regional Water Assn*Centerville, IA8 of 100.260 ppb28,215
Harris County Municipal Utility District 24Bellaire, TX1 of 40.250 ppb10,263
City of AllenAllen, TX17 of 170.249 ppb102,762
City of MurphyMurphy, TX17 of 170.249 ppb20,361
City of Princeton*Princeton, TX17 of 170.249 ppb16,932
City of Mesquite*Mesquite, TX17 of 170.249 ppb143,350
East Fork SUDWylie, TX17 of 170.249 ppb13,596
City of Frisco*Frisco, TX17 of 170.249 ppb192,261
City of McKinney*Mckinney, TX17 of 170.249 ppb169,710
City of Plano*Plano, TX17 of 170.249 ppb277,720
Town of ProsperProsper, TX17 of 170.249 ppb22,650
City of WylieWylie, TX17 of 170.249 ppb44,418
City of GarlandGarland, TX17 of 170.249 ppb236,786

* 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 Atrazine, but it likely has the contaminant in its water supply.