Know Your Environment. Protect Your Health.

Atrazine

City of Post Falls

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.

 

33

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018N/A00N/A
2019ND70ND
2020ND80ND
2021ND10ND
2022ND100ND
2023ND70ND

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
2019-11-13S210893ND
2019-11-13S210943ND
2019-11-18S211061ND
2019-12-09S211718ND
2019-12-16S211919ND
2019-12-18S211064ND
2019-12-19S211105ND
2020-01-08S212482ND
2020-01-08S202001013101ND
2020-01-08S212481ND
2020-01-08S212480ND
2020-01-08S212479ND
2020-01-08S212478ND
2020-01-08S212477ND
2020-01-08S212476ND
2021-11-30S202111052501ND
2022-02-09S202202020201ND
2022-03-09S202203020102ND
2022-03-09S202203020202ND
2022-03-14S202203025301ND
2022-03-14S202203025401ND
2022-04-27S202204053601ND
2022-06-06S202206008601ND
2022-06-07S202206010001ND
2022-07-13S202207033801ND
2022-11-01S2022110039ND
2023-01-25S202301040801ND
2023-05-15S202305028801ND
2023-07-25SMDG08170101ND
2023-07-25SMDG08170301ND
2023-07-25SMDG08170501ND
2023-07-25SMDG08170701ND
2023-12-13S202312023501ND