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EWG's Tap Water Database — 2021 UPDATE

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Atrazine

Sonoma County Water Agency

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

 

83

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND130ND
2015ND130ND
2016ND130ND
2017ND110ND
2018ND220ND
2019ND110ND

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
2014-08-191610-018-0430ND
2014-08-191610-001-0740ND
2014-08-191610-015-1000ND
2014-08-191610-012-0825ND
2014-08-191610-008-0630ND
2014-08-191610-003-0915ND
2014-08-201610-050-0825ND
2014-08-201610-020-0950ND
2014-08-201610-019-0440ND
2014-08-201610-017-1045ND
2014-08-201610-007-0640ND
2014-08-201610-002-0720ND
2014-08-271610-006-0750ND
2015-08-111610-018-0500ND
2015-08-111610-008-0700ND
2015-08-111610-017-0415ND
2015-08-111610-015-0945ND
2015-08-111610-012-0900ND
2015-08-111610-003-1130ND
2015-08-111610-001-0745ND
2015-08-121610-006-1145ND
2015-08-121610-020-1100ND
2015-08-121610-019-1005ND
2015-08-121610-050-0830ND
2015-08-121610-007-0640ND
2015-08-121610-002-0730ND
2016-08-301610-018-0850ND
2016-08-301610-017-1030ND
2016-08-301610-015-0950ND
2016-08-301610-012-0838ND
2016-08-301610-001-1340ND
2016-08-301610-002-0800ND
2016-08-301610-003-0920ND
2016-08-311610-008-1045ND
2016-08-311610-007-0930ND
2016-08-311610-006-0600ND
2016-08-311610-050-0800ND
2016-08-311610-020-0515ND
2016-10-121610-019-0900ND
2017-08-281610-015-0845ND
2017-08-281610-017-0920ND
2017-08-281610-003-0730ND
2017-08-281610-002-0950ND
2017-08-281610-001-0815ND
2017-08-291610-020-0515ND
2017-08-291610-008-0930ND
2017-08-291610-050-0745ND
2017-08-291610-019-1145ND
2017-08-291610-006-0610ND
2017-08-291610-007-1030ND
2018-08-271610-007-1110ND
2018-08-271610-008-1130ND
2018-08-279588-008-1130ND
2018-08-279588-007-1110ND
2018-08-279588-050-0930ND
2018-08-271610-050-0930ND
2018-09-049588-006-0830ND
2018-09-049588-002-1230ND
2018-09-049588-017-0935ND
2018-09-041610-003-0950ND
2018-09-049588-003-0950ND
2018-09-041610-017-0935ND
2018-09-041610-002-1230ND
2018-09-041610-006-0830ND
2018-09-049588-020-0915ND
2018-09-041610-020-0915ND
2018-09-041610-015-0900ND
2018-09-049588-015-0900ND
2018-09-101610-019-0910ND
2018-09-109588-019-0910ND
2018-09-119588-001-1115ND
2018-09-111610-001-1115ND
2019-09-091610-008-0930ND
2019-09-091610-050-0730ND
2019-09-091610-007-1100ND
2019-09-091610-006-0810ND
2019-09-091610-020-0850ND
2019-09-101610-002-0810ND
2019-09-101610-017-0740ND
2019-09-101610-003-0700ND
2019-09-101610-001-1040ND
2019-09-101610-015-0720ND
2019-11-121610-019-1145ND