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EWG's Tap Water Database — 2021 UPDATE

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Atrazine

Missouri American St. Louis County & St. Charles County

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.

MORE ABOUT THIS CONTAMINANT

 

120

Samples

0

Samples exceeding legal limit (MCL)

40

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.0850 ppb2010ND - 0.200 ppb
20150.125 ppb209ND - 0.500 ppb
20160.0800 ppb207ND - 0.400 ppb
20170.165 ppb2011ND - 0.600 ppb
20180.0800 ppb209ND - 0.300 ppb
20190.205 ppb2013ND - 0.700 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 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
2014-01-1524591301ND
2014-01-1524591701ND
2014-01-15245924010.1000 ppb
2014-01-15245929010.200 ppb
2014-01-15245931010.1000 ppb
2014-04-15251431010.200 ppb
2014-04-15251440010.200 ppb
2014-04-15251443010.200 ppb
2014-04-1625141301ND
2014-04-1625142201ND
2014-07-2226142901ND
2014-07-2226143601ND
2014-07-22261444010.200 ppb
2014-07-22261452010.200 ppb
2014-07-22261455010.200 ppb
2014-10-0827161801ND
2014-10-0927162101ND
2014-10-0927159601ND
2014-10-0927160101ND
2014-10-09271609010.1000 ppb
2015-01-06279098010.200 ppb
2015-01-06279096010.1000 ppb
2015-01-0727908401ND
2015-01-0727908001ND
2015-01-07279091010.1000 ppb
2015-04-2228624601ND
2015-04-22286273010.300 ppb
2015-04-22286276010.200 ppb
2015-04-2228625501ND
2015-04-22286264010.200 ppb
2015-07-13294635010.400 ppb
2015-07-13294644010.500 ppb
2015-07-13294647010.500 ppb
2015-07-1629461801ND
2015-07-1629462601ND
2015-10-2630316401ND
2015-10-2630317701ND
2015-10-2730314901ND
2015-10-2730315501ND
2015-10-2930782501ND
2016-01-05309365010.1000 ppb
2016-01-05309371010.1000 ppb
2016-01-05309373010.1000 ppb
2016-01-1130935201ND
2016-01-1130935701ND
2016-04-0531777201ND
2016-04-0531776201ND
2016-04-2031778201ND
2016-04-2031779201ND
2016-04-2031779501ND
2016-07-0632596701ND
2016-07-06325984010.400 ppb
2016-07-0632597501ND
2016-07-06325994010.400 ppb
2016-07-06325997010.400 ppb
2016-10-2833955301ND
2016-10-2833948101ND
2016-10-2833955001ND
2016-10-28339551010.1000 ppb
2016-10-3133955201ND
2017-01-10343215010.1000 ppb
2017-01-1134320201ND
2017-01-1134320701ND
2017-01-20343221010.1000 ppb
2017-01-2034322301ND
2017-04-11351219010.400 ppb
2017-04-11351228010.400 ppb
2017-04-11351231010.400 ppb
2017-04-1935119901ND
2017-04-1935120901ND
2017-07-04361437010.500 ppb
2017-07-04361446010.600 ppb
2017-07-04361449010.500 ppb
2017-07-1436142201ND
2017-07-1436142901ND
2017-10-16372294010.1000 ppb
2017-10-1737228101ND
2017-10-1737228601ND
2017-10-24372303010.1000 ppb
2017-10-24372306010.1000 ppb
2018-01-09381455010.1000 ppb
2018-01-18381460010.1000 ppb
2018-01-1838146201ND
2018-01-1938144401ND
2018-01-1938144801ND
2018-04-0639051701ND
2018-04-0639052601ND
2018-04-16390535010.200 ppb
2018-04-16390543010.1000 ppb
2018-04-16390546010.1000 ppb
2018-07-23402969010.300 ppb
2018-07-23402972010.300 ppb
2018-07-2440294501ND
2018-07-2440295201ND
2018-07-26402960010.300 ppb
2018-10-0941291001ND
2018-10-0941291501ND
2018-10-09412923010.1000 ppb
2018-10-0941293201ND
2018-10-0941293501ND
2019-01-0942526401ND
2019-01-0942526801ND
2019-01-09425275010.200 ppb
2019-01-09425280010.200 ppb
2019-01-09425282010.200 ppb
2019-04-0843598201ND
2019-04-0843599201ND
2019-04-09436001010.200 ppb
2019-04-09436011010.200 ppb
2019-04-09436012010.200 ppb
2019-07-10452307010.200 ppb
2019-07-1045231701ND
2019-07-10452327010.700 ppb
2019-07-10452339010.700 ppb
2019-07-10452340010.700 ppb
2019-10-0746956801ND
2019-10-0746957401ND
2019-10-07469582010.200 ppb
2019-10-07469591010.200 ppb
2019-10-07469593010.200 ppb