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EWG's Tap Water Database — 2021 UPDATE

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Atrazine

Archie PWS

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.

 

24

Samples

0

Samples exceeding legal limit (MCL)

16

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.253 ppb43ND - 0.410 ppb
20150.360 ppb43ND - 0.650 ppb
20160.280 ppb43ND - 0.440 ppb
20170.323 ppb43ND - 0.640 ppb
20180.405 ppb43ND - 0.780 ppb
20190.210 ppb41ND - 0.840 ppb

ppb = parts per billion

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

All test results

Date Lab ID Result
2014-02-10AC189170.270 ppb
2014-05-15AC23670ND
2014-08-12AC324540.410 ppb
2014-11-14AC386670.330 ppb
2015-02-09AC424830.650 ppb
2015-05-08AC47040ND
2015-08-14AC580110.370 ppb
2015-11-06AC631860.420 ppb
2016-02-05AC668590.440 ppb
2016-05-09AC72541ND
2016-08-12AC822200.400 ppb
2016-11-14AC877220.280 ppb
2017-02-03AC913090.310 ppb
2017-05-05AC96251ND
2017-08-18AD040250.640 ppb
2017-11-21AD098360.340 ppb
2018-02-13AD147890.440 ppb
2018-05-07AD20792ND
2018-08-03AD315670.400 ppb
2018-11-08AD360750.780 ppb
2019-02-25AD398770.840 ppb
2019-05-16AD47759ND
2019-09-15AD54351ND
2019-11-08AD58376ND