Know Your Environment. Protect Your Health.

Atrazine

Smithville Water System

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.

 

14

Samples

0

Samples exceeding legal limit (MCL)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.149 ppb42ND - 0.452 ppb
20190.121 ppb21ND - 0.242 ppb
20200.199 ppb220.150 ppb - 0.248 ppb
2021ND10ND
2022ND10ND
20230.0465 ppb41ND - 0.186 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 Result
2018-01-09ND
2018-05-090.145 ppb
2018-07-110.452 ppb
2018-10-23ND
2019-01-31ND
2019-07-250.242 ppb
2020-06-300.248 ppb
2020-08-310.150 ppb
2021-05-26ND
2022-05-31ND
2023-03-25ND
2023-04-28ND
2023-07-300.186 ppb
2023-10-24ND