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EWG's Tap Water Database — 2019 UPDATE

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Atrazine

City of Gilroy

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.

 

36

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND180ND
2013N/A00N/A
2014N/A00N/A
2015ND180ND
2016N/A00N/A
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 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
2012-05-215810-001-0850ND
2012-05-215810-006-1315ND
2012-05-215810-002-1135ND
2012-05-215810-004-1045ND
2012-05-225810-009-1035ND
2012-05-225810-010-1115ND
2012-05-225810-008-0955ND
2012-05-225810-007-0745ND
2012-05-225810-011-0835ND
2012-08-225810-001-0845ND
2012-08-225810-002-1025ND
2012-08-225810-004-1000ND
2012-08-225810-006-1325ND
2012-08-225810-008-1050ND
2012-08-225810-009-1110ND
2012-08-225810-011-1300ND
2012-08-235810-010-0855ND
2012-08-235810-007-0825ND
2015-05-205810-007-1300ND
2015-05-205810-008-1025ND
2015-05-205810-006-0945ND
2015-05-205810-009-1100ND
2015-05-205810-010-0810ND
2015-05-215810-004-1250ND
2015-05-215810-002-1010ND
2015-05-215810-011-0955ND
2015-05-215810-001-0800ND
2015-08-195810-007-1120ND
2015-08-195810-008-1019ND
2015-08-195810-004-1320ND
2015-08-195810-009-1044ND
2015-08-195810-002-1250ND
2015-08-195810-010-1203ND
2015-08-195810-001-1225ND
2015-08-195810-006-0948ND
2015-08-205810-011-0845ND