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EWG's Tap Water Database — 2019 UPDATE

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Simazine

City of Manteca

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.

 

15

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND10ND
2013ND10ND
2014ND40ND
2015ND80ND
2016ND10ND
2017N/A00N/A

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
2012-05-085810-012-0900ND
2013-05-155810-034-0746ND
2014-01-145810-014-0928ND
2014-01-145810-032-1010ND
2014-06-105810-042-0750ND
2014-08-295810-040-0616ND
2015-05-125810-013-0750ND
2015-05-125810-016-0725ND
2015-05-125810-028-1535ND
2015-06-095810-015-0614ND
2015-06-095810-049-0650ND
2015-08-115810-015-0815ND
2015-12-095810-013-0625ND
2015-12-095810-038-0910ND
2016-06-145810-038-0645ND