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EWG's Tap Water Database — 2021 UPDATE

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Atrazine

City of Houston

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

 

163

Samples

0

Samples exceeding legal limit (MCL)

60

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.181 ppb1410ND - 0.610 ppb
20150.0533 ppb3611ND - 0.250 ppb
20160.148 ppb2611ND - 0.770 ppb
20170.118 ppb2611ND - 0.910 ppb
20180.0562 ppb3910ND - 0.330 ppb
20190.0709 ppb2211ND - 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 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
2014-02-03AC411280.130 ppb
2014-03-14AC471830.360 ppb
2014-03-14AC471840.360 ppb
2014-03-14AC471850.390 ppb
2014-04-16AC509280.120 ppb
2014-04-16AC509290.130 ppb
2014-04-17AC51177ND
2014-06-03AC558310.180 ppb
2014-06-03AC558260.610 ppb
2014-07-15AC597330.120 ppb
2014-07-15AC597290.130 ppb
2014-10-08AC69250ND
2014-12-18AC75488ND
2014-12-18AC75489ND
2015-03-04AC83061ND
2015-03-04AC830590.1000 ppb
2015-03-05AC83064ND
2015-03-05AC830650.1000 ppb
2015-03-24AC85944ND
2015-06-04AC94707ND
2015-06-04AC94705ND
2015-06-04AC94710ND
2015-06-04AC94709ND
2015-06-04AC947060.130 ppb
2015-06-04AC947080.190 ppb
2015-07-22AD00679ND
2015-07-22AD00678ND
2015-09-17AD076490.130 ppb
2015-09-17AD07648ND
2015-10-22AD11601ND
2015-10-22AD11600ND
2015-10-22AD11602ND
2015-10-22AD11596ND
2015-10-22AD11599ND
2015-10-22AD11598ND
2015-10-22AD11597ND
2015-11-12AD13457ND
2015-11-12AD13444ND
2015-11-12AD13456ND
2015-11-12AD13453ND
2015-11-12AD134430.250 ppb
2015-11-12AD13452ND
2015-11-12AD13455ND
2015-11-12AD134540.230 ppb
2015-11-16AD136990.220 ppb
2015-11-16AD137010.220 ppb
2015-11-16AD137000.210 ppb
2015-11-17AD139070.140 ppb
2015-12-08AD16048ND
2015-12-08AD16049ND
2016-03-03AD27014ND
2016-03-16AD292230.480 ppb
2016-03-16AD292220.440 ppb
2016-03-17AD294320.460 ppb
2016-03-17AD29430ND
2016-03-17AD29435ND
2016-03-17AD294330.420 ppb
2016-03-23AD30249ND
2016-03-23AD30250ND
2016-03-23AD302480.770 ppb
2016-03-23AD30251ND
2016-06-08AD39863ND
2016-06-08AD39861ND
2016-06-08AD398620.240 ppb
2016-06-08AD39860ND
2016-06-15AD408290.240 ppb
2016-06-16AD41041ND
2016-06-16AD41042ND
2016-09-20AD504590.220 ppb
2016-09-20AD504600.210 ppb
2016-09-21AD508890.150 ppb
2016-09-21AD50890ND
2016-10-06AD52704ND
2016-10-06AD527060.210 ppb
2016-10-06AD52705ND
2016-12-02AD60483ND
2017-01-26AD67327ND
2017-01-26AD67326ND
2017-02-28AD726140.260 ppb
2017-02-28AD726150.250 ppb
2017-03-01AD728830.310 ppb
2017-03-01AD728820.370 ppb
2017-03-02AD732830.330 ppb
2017-03-02AD732840.910 ppb
2017-03-28AD77273ND
2017-03-28AD772740.130 ppb
2017-04-27AD81596ND
2017-04-27AD81598ND
2017-04-27AD81597ND
2017-07-06AD88548ND
2017-07-06AD88549ND
2017-07-25AD906750.160 ppb
2017-07-26AD90935ND
2017-07-26AD90934ND
2017-09-11AD956330.120 ppb
2017-09-11AD95634ND
2017-09-26AD98128ND
2017-09-26AD981290.120 ppb
2017-09-26AD981300.110 ppb
2017-11-07AE03932ND
2017-11-07AE03938ND
2017-12-04AE06640ND
2018-01-18AE09332ND
2018-01-18AE093330.130 ppb
2018-01-18AE09334ND
2018-01-18AE093350.120 ppb
2018-01-23AE09967ND
2018-01-23AE09969ND
2018-01-23AE09968ND
2018-01-23AE099660.190 ppb
2018-01-23AE099700.170 ppb
2018-01-31AE116850.240 ppb
2018-03-29AE20736ND
2018-03-29AE20734ND
2018-03-29AE20732ND
2018-03-29AE20738ND
2018-03-29AE20737ND
2018-03-29AE20735ND
2018-03-29AE207330.110 ppb
2018-04-26AE24261ND
2018-04-26AE24267ND
2018-04-26AE24263ND
2018-04-26AE24266ND
2018-04-26AE24262ND
2018-04-26AE24264ND
2018-04-26AE24265ND
2018-05-22AE27325ND
2018-05-22AE27326ND
2018-05-22AE27324ND
2018-05-22AE27323ND
2018-07-19AE33997ND
2018-07-19AE33999ND
2018-07-19AE33998ND
2018-08-03AE359220.290 ppb
2018-08-15AE372520.320 ppb
2018-08-15AE372530.330 ppb
2018-08-15AE372510.290 ppb
2018-08-29AE38821ND
2018-09-26AE41819ND
2018-09-26AE41818ND
2018-11-14AE46119ND
2019-01-15AE502690.1000 ppb
2019-01-15AE502680.110 ppb
2019-01-16AE50275ND
2019-01-16AE502700.120 ppb
2019-03-06AE57464ND
2019-03-06AE57462ND
2019-03-06AE57458ND
2019-03-06AE574630.180 ppb
2019-03-06AE57465ND
2019-04-11AE62164ND
2019-07-24AE760490.140 ppb
2019-07-25AE760510.190 ppb
2019-07-25AE760500.200 ppb
2019-09-23AE842840.120 ppb
2019-09-23AE842830.1000 ppb
2019-10-10AE863710.170 ppb
2019-11-18AE89651ND
2019-11-18AE89653ND
2019-11-18AE89652ND
2019-11-22AE90470ND
2019-11-22AE90471ND
2019-12-02AE908610.130 ppb