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EWG's Tap Water Database — 2021 UPDATE

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Simazine

Norwalk City

Simazine is a hormone-disrupting herbicide related to atrazine. It affects the male and female reproductive systems. In studies of laboratory animals, simazine increases blood levels of estrogen, decreases prolactin and progesterone, and causes mammary and ovarian tumors.

 

17

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND30ND
2015ND30ND
2016ND20ND
2017ND30ND
20180.297 ppb330.230 ppb - 0.370 ppb
2019ND30ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.1 ppb

The EWG Health Guideline of 0.1 ppb for simazine 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) 4 ppb

The legal limit for simazine, established in 1992, was based on toxicity studies 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
2014-04-14041514016ND
2014-05-14051514021ND
2014-06-23062414017ND
2015-04-08040915023ND
2015-05-13051415011ND
2015-06-10061115031ND
2016-04-06040716027ND
2016-06-01060216025ND
2017-04-10041117032ND
2017-05-15051617031ND
2017-06-20062117037ND
2018-04-2418-17652-020.290 ppb
2018-05-0118-17863-010.370 ppb
2018-06-0518-20675-010.230 ppb
2019-04-0219-16343-01ND
2019-05-0619-19010-01ND
2019-06-0419-21158-01ND