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EWG's Tap Water Database — 2019 UPDATE

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Atrazine

Wellborn SUD

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.

 

26

Samples

0

Samples exceeding legal limit (MCL)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20120.0220 ppb51ND - 0.110 ppb
2013ND30ND
2014ND30ND
2015ND40ND
20160.0200 ppb61ND - 0.120 ppb
2017ND50ND

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
2012-02-01AB79955ND
2012-02-01AB79956ND
2012-06-18AB93099ND
2012-06-18AB930980.110 ppb
2012-09-12AC00856ND
2013-02-061302228005ND
2013-12-12Q1317624019ND
2013-12-12Q1317624021ND
2014-02-13AC42895ND
2014-05-12AC53845ND
2014-09-10AC66622ND
2015-03-24AC85937ND
2015-03-24AC85936ND
2015-03-24AC85938ND
2015-03-24AC85935ND
2016-03-09AD28036ND
2016-03-09AD28049ND
2016-03-09AD28047ND
2016-06-14AD405520.120 ppb
2016-09-30AD52164ND
2016-12-08AD61426ND
2017-03-07AD73826ND
2017-05-22AD85109ND
2017-09-19AD96962ND
2017-11-21AE05643ND
2017-11-21AE05642ND