Atrazine
Regional Water Authority
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | N/A | 0 | 0 | N/A |
2015 | ND | 1 | 0 | ND |
2016 | ND | 19 | 0 | ND |
2017 | N/A | 0 | 0 | N/A |
2018 | N/A | 0 | 0 | N/A |
2019 | ND | 22 | 0 | ND |
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 |
---|---|---|
2015-06-25 | SOC 200419193 | ND |
2016-05-16 | SOC 200439626 | ND |
2016-05-16 | SOC 200439625 | ND |
2016-05-16 | SOC 200439623 | ND |
2016-05-16 | SOC 200439622 | ND |
2016-05-16 | SOC 200439619 | ND |
2016-05-16 | SOC 200439620 | ND |
2016-05-16 | SOC 200439627 | ND |
2016-05-16 | SOC 200439628 | ND |
2016-08-29 | SOC 200448468 | ND |
2016-08-29 | SOC 200448473 | ND |
2016-08-29 | SOC 200448472 | ND |
2016-08-29 | SOC 200448466 | ND |
2016-08-29 | SOC 200448465 | ND |
2016-08-29 | SOC 200448469 | ND |
2016-08-29 | SOC 200448470 | ND |
2016-08-29 | SOC 200448471 | ND |
2016-08-30 | SOC 200448554 | ND |
2016-09-28 | SOC 200451204 | ND |
2016-11-22 | SOC 200455270 | ND |
2019-05-08 | SOC 200531300 | ND |
2019-05-28 | SOC 200533720 | ND |
2019-05-28 | SOC 200533659 | ND |
2019-05-28 | SOC 200533660 | ND |
2019-05-28 | SOC 200533803 | ND |
2019-05-28 | SOC 200533719 | ND |
2019-05-28 | SOC 200533804 | ND |
2019-05-29 | SOC 200533881 | ND |
2019-05-29 | SOC 200533880 | ND |
2019-05-29 | SOC 200533867 | ND |
2019-05-29 | SOC 200533868 | ND |
2019-08-26 | SOC 200546200 | ND |
2019-08-26 | SOC 200546198 | ND |
2019-08-26 | SOC 200546197 | ND |
2019-08-27 | SOC 200546267 | ND |
2019-08-27 | SOC 200546268 | ND |
2019-08-27 | SOC 200546302 | ND |
2019-08-27 | SOC 200546303 | ND |
2019-08-28 | SOC 200546738 | ND |
2019-08-28 | SOC 200546737 | ND |
2019-08-28 | SOC 200546736 | ND |
2019-08-28 | SOC 200546553 | ND |