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EWG's Tap Water Database — 2021 UPDATE

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Atrazine

Lafourche Water District 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.

MORE ABOUT THIS CONTAMINANT

 

58

Samples

2

Samples exceeding legal limit (MCL)

20

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.125 ppb82ND - 0.500 ppb
2015ND80ND
20160.530 ppb84ND - 1.50 ppb
2017ND80ND
20180.133 ppb84ND - 0.340 ppb
20191.02 ppb1810ND - 5.50 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
2014-02-03AD88683ND
2014-02-03AD88683ND
2014-02-24AD892940.500 ppb
2014-02-24AD892940.500 ppb
2014-10-06AD98270ND
2014-10-06AD98270ND
2014-10-27AD98954ND
2014-10-27AD98954ND
2015-03-3135181766005ND
2015-03-3135181766005ND
2015-06-0835192498004ND
2015-06-0835192498004ND
2015-09-2435208879009ND
2015-09-2435208879009ND
2015-10-1435212325002ND
2015-10-1435212325002ND
2016-03-01352321490010.620 ppb
2016-03-01352321490010.620 ppb
2016-03-15352343930051.50 ppb
2016-03-15352343930051.50 ppb
2016-11-1435277515002ND
2016-11-1435277515002ND
2016-11-2935279934001ND
2016-11-2935279934001ND
2017-01-3135292293005ND
2017-01-3135292293005ND
2017-02-1435295627001ND
2017-02-1435295627001ND
2017-10-1635342351004ND
2017-10-1635342351004ND
2017-11-0135345512001ND
2017-11-0135345512001ND
2018-01-2535370415009ND
2018-01-2535370415009ND
2018-02-2635377894001ND
2018-02-2635377894001ND
2018-07-23354063050010.340 ppb
2018-07-23354063050010.340 ppb
2018-08-23354131960010.190 ppb
2018-08-23354131960010.190 ppb
2019-01-2935445082001ND
2019-01-2935445082001ND
2019-02-18354493740015.50 ppb
2019-02-18354493740015.50 ppb
2019-03-1135453863001ND
2019-03-1135453863001ND
2019-05-08354669410010.480 ppb
2019-05-08354669410010.480 ppb
2019-07-24354848550010.500 ppb
2019-07-24354848550010.500 ppb
2019-08-01354867820012.40 ppb
2019-08-01354867820012.40 ppb
2019-08-28354940520010.280 ppb
2019-08-28354940520010.280 ppb
2019-10-0335502721001ND
2019-10-0335502721002ND
2019-10-0335502721001ND
2019-10-0335502721002ND