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EWG's Tap Water Database — 2021 UPDATE

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Atrazine

San Jose Water Company

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.

 

63

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
2014ND150ND
2015ND40ND
2016ND70ND
2017ND260ND
2018ND40ND
2019ND70ND

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
2014-01-131610-182-0900ND
2014-01-131610-181-0910ND
2014-03-051610-180-0915ND
2014-03-061610-183-0934ND
2014-04-091610-185-0830ND
2014-05-071610-075-1014ND
2014-05-091610-025-0845ND
2014-06-091610-126-0945ND
2014-06-091610-131-1010ND
2014-06-161610-186-0845ND
2014-08-051610-184-0930ND
2014-08-141610-178-0930ND
2014-09-111610-111-0936ND
2014-09-251610-187-0900ND
2014-10-021610-184-0855ND
2015-01-141610-186-1355ND
2015-02-231610-185-0840ND
2015-03-051610-156-0922ND
2015-04-091610-186-1015ND
2016-02-229588-068-0955ND
2016-03-301610-075-1407ND
2016-05-049590-198-1200ND
2016-05-201610-075-0900ND
2016-06-159590-199-1300ND
2016-07-269590-197-1230ND
2016-10-211610-168-0910ND
2017-01-101610-126-0904ND
2017-01-171610-027-0950ND
2017-01-189590-068-1055ND
2017-01-191610-029-1210ND
2017-01-199590-029-1210ND
2017-01-269590-086-1415ND
2017-01-319590-094-1215ND
2017-01-319590-178-1250ND
2017-01-319590-126-1040ND
2017-02-139590-005-1440ND
2017-03-271610-168-0900ND
2017-04-261610-126-1015ND
2017-05-085867-027-0925ND
2017-05-091610-156-0955ND
2017-05-101610-029-0920ND
2017-06-081610-168-0930ND
2017-07-201610-131-0910ND
2017-07-211610-111-1035ND
2017-07-311610-168-0855ND
2017-08-091610-156-0940ND
2017-08-171610-180-0840ND
2017-09-291610-177-1105ND
2017-11-071610-168-0910ND
2017-11-071610-180-0845ND
2017-12-071610-111-1250ND
2017-12-141610-075-1335ND
2018-01-171610-202-1135ND
2018-01-171610-075-1150ND
2018-04-301610-075-0950ND
2018-04-301610-202-0945ND
2019-01-161610-199-0915ND
2019-01-291610-075-0815ND
2019-01-291610-202-0841ND
2019-04-111610-075-1105ND
2019-04-111610-202-1105ND
2019-05-061610-199-1015ND
2019-07-231610-199-0945ND