Know Your Environment. Protect Your Health.

Atrazine

Tensas Water District Association

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.

 

29

Samples

0

Samples exceeding legal limit (MCL)

27

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.815 ppb440.790 ppb - 0.840 ppb
20191.24 ppb660.530 ppb - 1.60 ppb
20200.706 ppb54ND - 1.10 ppb
20210.972 ppb54ND - 2.70 ppb
20220.705 ppb440.570 ppb - 0.790 ppb
20230.800 ppb550.540 ppb - 1.30 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
2018-01-08353678240020.790 ppb
2018-01-08353678240020.790 ppb
2018-07-30354078780010.840 ppb
2018-07-30354078780010.840 ppb
2019-01-14354426030030.530 ppb
2019-01-14354426030030.530 ppb
2019-07-31354867470011.60 ppb
2019-07-31354867470011.60 ppb
2019-10-04355028110011.60 ppb
2019-10-04355028110011.60 ppb
2020-01-06355231120010.800 ppb
2020-04-15355444250010.770 ppb
2020-08-1235570539001ND
2020-09-09355771160011.10 ppb
2020-11-10355917830010.860 ppb
2021-01-1835605842001ND
2021-05-13356335230022.70 ppb
2021-09-15356643920010.670 ppb
2021-09-15356643940010.650 ppb
2021-12-03356821770010.840 ppb
2022-01-18356921120030.730 ppb
2022-04-11357119460010.730 ppb
2022-08-15357411760030.790 ppb
2022-12-07357666430010.570 ppb
2023-01-17357736610010.610 ppb
2023-02-06357781770020.540 ppb
2023-04-12357940720010.620 ppb
2023-07-18358140930011.30 ppb
2023-11-07358417470010.930 ppb