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EWG's Tap Water Database — 2021 UPDATE

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Atrazine

Bi County WSC 1

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.

 

33

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
2015ND110ND
2016ND20ND
2017ND20ND
2018ND110ND
2019ND50ND

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
2014-07-14Q1427473013ND
2014-07-14Q1427473012ND
2015-02-05Q1504623008ND
2015-02-05Q1504623007ND
2015-02-05Q1504623009ND
2015-02-05Q1504623010ND
2015-02-05Q1504623011ND
2015-02-05Q1504623012ND
2015-02-05Q1504623013ND
2015-04-16Q1514410012ND
2015-04-16Q1514410011ND
2015-04-16Q1514410010ND
2015-04-16Q1514410009ND
2016-04-19Q1615295019ND
2016-10-06Q1642553015ND
2017-01-05Q1700559026ND
2017-01-05Q1700559004ND
2018-01-09Q1800903033ND
2018-01-09Q1800903032ND
2018-01-09Q1800903031ND
2018-01-09Q1800903030ND
2018-01-09Q1800903029ND
2018-01-09Q1800903028ND
2018-01-09Q1800903027ND
2018-01-09Q1800903025ND
2018-01-09Q1800903024ND
2018-01-09Q1800903023ND
2018-09-10Q1835620001ND
2019-01-15Q1902083019ND
2019-01-15Q1902083018ND
2019-06-11Q1934121006ND
2019-08-07Q1951925008ND
2019-10-14Q1972404009ND