Know Your Environment. Protect Your Health.

Atrazine

CTWC - Shoreline Region-Guilford 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.

 

32

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND10ND
2019ND150ND
2020N/A00N/A
2021ND10ND
2022ND150ND
2023N/A00N/A

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
2018-07-09CA86688ND
2019-01-30SOC 200520057ND
2019-06-06SOC 200535308ND
2019-06-06SOC 200535309ND
2019-06-11SOC 200536055ND
2019-06-11SOC 200536054ND
2019-06-19SOC 200542695ND
2019-06-24SOC 200537520ND
2019-07-29SOC 200542348ND
2019-07-30SOC 200542453ND
2019-07-31SOC 200542480ND
2019-07-31SOC 200542466ND
2019-07-31SOC 200542497ND
2019-07-31SOC 200542499ND
2019-07-31SOC 200542468ND
2019-08-14SOC 200544869ND
2021-09-30S300072074 300072088ND
2022-06-14CL56474ND
2022-06-14CL56470ND
2022-06-14CL56472ND
2022-06-15CL57887ND
2022-06-15CL57885ND
2022-06-22CL62297ND
2022-06-28CL66245ND
2022-07-18CL80434ND
2022-07-18CL80436ND
2022-07-18CL80438ND
2022-07-18CL80432ND
2022-07-25CL88838ND
2022-07-25CL88842ND
2022-08-29CM17828ND
2022-10-19CM66672ND