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EWG's Tap Water Database

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Atrazine

Clearwater Water System

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.

 

28

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2010ND60ND
2011ND60ND
2012ND60ND
2013ND30ND
2014ND30ND
2015ND40ND

ppb = parts per billion.

State and national drinking water standards and health guidelines

Health Guideline 0.15 ppb

The health guideline of 0.15 ppb for atrazine 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 cancer.

ppb = parts per billion.

EPA Maximum Contaminant
Level (MCL) 3 ppb

The enforceable federal standard that defines the highest level of a contaminant allowed in drinking water.

ppb = parts per billion.

EPA Maximum Contaminant
Level Goal (MCLG)3 ppb

A non-enforceable federal health guideline. For cancer-causing chemicals, these health goals are typically set to zero.

ppb = parts per billion.

All test results

Date Result
2010-02-10ND
2010-02-10ND
2010-02-11ND
2010-08-17ND
2010-08-17ND
2010-08-17ND
2011-02-16ND
2011-02-16ND
2011-02-16ND
2011-08-26ND
2011-08-26ND
2011-08-26ND
2012-02-10ND
2012-02-10ND
2012-02-10ND
2012-07-13ND
2012-07-13ND
2012-07-13ND
2013-02-01ND
2013-02-01ND
2013-02-01ND
2014-02-13ND
2014-08-14ND
2014-08-14ND
2015-01-13ND
2015-01-13ND
2015-05-07ND
2015-07-29ND