Know Your Environment. Protect Your Health.

Atrazine

Houma Water Treatment Service Area

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)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND20ND
2019ND40ND
20200.0175 ppb21ND - 0.0350 ppb
20210.0845 ppb220.0730 ppb - 0.0960 ppb
20220.0730 ppb220.0580 ppb - 0.0880 ppb
20230.264 ppb220.0880 ppb - 0.440 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 Lab ID Result
2018-08-2335413192001ND
2018-08-2335413192001ND
2019-02-1835449356001ND
2019-02-1835449356001ND
2019-08-2835494058001ND
2019-08-2835494058001ND
2020-01-2235526020001ND
2020-12-03355964620010.0350 ppb
2021-03-11356192880010.0960 ppb
2021-11-04356757770010.0730 ppb
2022-03-02357014330010.0880 ppb
2022-10-12357531320010.0580 ppb
2023-04-11357919370010.0880 ppb
2023-12-21358499730010.440 ppb