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EWG's Tap Water Database — 2019 UPDATE

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Simazine

City of South Houston

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.

 

33

Samples

0

Samples exceeding legal limit (MCL)

16

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20120.0920 ppb550.0800 ppb - 0.110 ppb
20130.138 ppb550.130 ppb - 0.150 ppb
20140.0180 ppb51ND - 0.0900 ppb
20150.0886 ppb75ND - 0.200 ppb
20160.175 ppb65ND - 0.240 ppb
20170.114 ppb53ND - 0.200 ppb

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
2012-02-06AB802760.1000 ppb
2012-02-06AB802750.0800 ppb
2012-02-06AB802710.110 ppb
2012-02-06AB802740.0800 ppb
2012-02-06AB802670.0900 ppb
2013-01-14AC076480.140 ppb
2013-01-14AC076490.140 ppb
2013-01-14AC076500.150 ppb
2013-01-14AC076440.130 ppb
2013-01-14AC076470.130 ppb
2014-01-14AC38903ND
2014-01-14AC38904ND
2014-01-14AC38908ND
2014-01-14AC38906ND
2014-01-14AC389050.0900 ppb
2015-01-21AC771370.0700 ppb
2015-01-21AC771310.0900 ppb
2015-01-21AC77136ND
2015-01-21AC77129ND
2015-01-21AC771300.0800 ppb
2015-09-15AD071800.200 ppb
2015-10-06AD096520.180 ppb
2016-01-14AD183950.150 ppb
2016-01-14AD183820.220 ppb
2016-01-14AD183850.220 ppb
2016-01-14AD183880.220 ppb
2016-01-14AD183910.240 ppb
2016-04-08AD32661ND
2017-01-06AD63756ND
2017-02-10AD70495ND
2017-03-01AD728800.180 ppb
2017-03-01AD728810.190 ppb
2017-03-01AD728790.200 ppb