Know Your Environment. Protect Your Health.

Atrazine

Tesoro Viejo Master Mwc, Inc.

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.

 

22

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND30ND
2019ND40ND
2020ND60ND
2021ND40ND
2022ND40ND
2023ND10ND

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
2018-08-31CA2010017_002_002-201808310845ND
2018-12-06CA2010017_006_006-201812061037ND
2018-12-12CA2010017_001_001-201812121105ND
2019-03-20CA2010017_001_001-201903200815ND
2019-06-12CA2010017_006_006-201906121015ND
2019-08-21CA2010017_002_002-201908210955ND
2019-11-13CA2010017_006_006-201911131010ND
2020-02-05CA2010017_006_006-202002051000ND
2020-05-13CA2010017_006_006-202005131000ND
2020-06-03CA2010017_002_002-202006031215ND
2020-06-09CA2010017_001_001-202006090845ND
2020-09-02CA2010017_001_001-202009020840ND
2020-12-09CA2010017_001_001-202012090945ND
2021-03-16CA2010017_001_001-202103161000ND
2021-06-28CA2010017_002_002-202106280955ND
2021-09-15CA2010017_001_001-202109151045ND
2021-12-15CA2010017_001_001-202112151110ND
2022-06-08CA2010017_001_001-202206080930ND
2022-07-06CA2010017_002_002-202207060900ND
2022-09-13CA2010017_001_001-202209131030ND
2022-12-05CA2010017_001_001-202212051045ND
2023-02-14CA2010017_006_006-202302141040ND