Know Your Environment. Protect Your Health.

Atrazine

City of Nampa

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.

 

59

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND10ND
2019ND120ND
2020ND40ND
2021ND120ND
2022ND210ND
2023ND90ND

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
2018-10-08S1850028ND
2019-08-15S1940600ND
2019-08-15S1940599ND
2019-09-17S1946663ND
2019-09-17S1946664ND
2019-09-17S1946661ND
2019-09-17S1946666ND
2019-09-17S1946665ND
2019-09-18S1947017ND
2019-09-18S1947010ND
2019-09-18S1947008ND
2019-09-18S1947009ND
2019-09-18S1947007ND
2020-02-12S2006566ND
2020-07-14S2033050ND
2020-10-01S2049166ND
2020-10-19S2052617ND
2021-02-08S2105827ND
2021-02-08S2105826ND
2021-02-08S2105824ND
2021-02-08S2105828ND
2021-02-08S2105829ND
2021-03-08S2110611ND
2021-03-08S2110613ND
2021-03-08S2110615ND
2021-04-21S2118306ND
2021-04-21S2118309ND
2021-04-21S2118307ND
2021-11-09S2160872ND
2022-02-02S2205301ND
2022-02-02S2205304ND
2022-06-09S2227610ND
2022-08-18S2240737ND
2022-08-18S2240738ND
2022-08-18S2240734ND
2022-08-18S2240733ND
2022-08-18S2240732ND
2022-08-18S2240731ND
2022-08-19S2240998ND
2022-08-19S2240997ND
2022-08-19S2240996ND
2022-08-19S2240995ND
2022-11-16S2256980ND
2022-11-16S2256971ND
2022-11-16S2256972ND
2022-11-16S2256973ND
2022-11-16S2256974ND
2022-11-16S2256976ND
2022-11-16S2256977ND
2022-11-16S2256978ND
2023-01-04SMDA0147-01ND
2023-02-01S2302073-01ND
2023-05-17S2309616-01ND
2023-05-17S2309616-02ND
2023-05-17S2309616-03ND
2023-08-03S2316312-01ND
2023-08-03S2316312-02ND
2023-10-31S2323606-01ND
2023-11-30S2325655-01ND