Know Your Environment. Protect Your Health.

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.

 

47

Samples

2

Samples exceeding legal limit (MCL)

22

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.133 ppb84ND - 0.340 ppb
20191.02 ppb1810ND - 5.50 ppb
20200.363 ppb83ND - 2.50 ppb
20210.231 ppb550.0710 ppb - 0.520 ppb
20220.0840 ppb440.0360 ppb - 0.170 ppb
20230.427 ppb440.0490 ppb - 1.50 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

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
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
2019-10-0335502721002ND
2019-10-0335502721001ND
2019-10-0335502721001ND
2019-10-0335502721002ND
2020-01-2235526013001ND
2020-01-2235526013002ND
2020-04-1535544202001ND
2020-04-1535544202002ND
2020-07-24355675660010.200 ppb
2020-07-24355675680010.200 ppb
2020-10-1535585520001ND
2020-12-03355964680012.50 ppb
2021-01-14356051160020.0710 ppb
2021-03-11356192760010.120 ppb
2021-03-11356192850010.350 ppb
2021-11-04356757740010.0940 ppb
2021-12-16356856950010.520 ppb
2022-03-02357014290010.0360 ppb
2022-03-02357014320010.0530 ppb
2022-08-25357427310010.170 ppb
2022-10-12357531300010.0770 ppb
2023-02-27357824180010.0490 ppb
2023-03-27357893050010.0600 ppb
2023-10-23358367210010.1000 ppb
2023-12-21358499790011.50 ppb