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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

City of Alhambra

Perchlorate, a component of rocket fuel, occurs both naturally and as a synthetic chemical. Ingested perchlorate interferes with thyroid function. Exposure to perchlorate during pregnancy and childhood can impair cognitive development. Read More.

According to the EPA, perchlorate likely contaminates the water of more than 16 million Americans. Perchlorate interferes with iodine uptake in the thyroid, which can result in reduced thyroid hormones and an impact on metabolism, physical development and cognitive development. Children and developing fetuses are the most at risk from perchlorate contamination.

Perchlorate is the only unregulated contaminant for which the EPA has attempted to set a federal drinking water standard since 1996. However, the agency has yet to propose a draft limit for this contaminant. Perchlorate in drinking water is regulated in Arizona, California, Massachusetts, New Jersey, New York and Texas. California set a public health goal of 1 part per billion for perchlorate in 2015.

Click here to read more about perchlorate.

MORE ABOUT THIS CONTAMINANT

 

236

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.121 ppb471ND - 5.70 ppb
20150.107 ppb451ND - 4.80 ppb
20160.361 ppb361ND - 13.0 ppb
2017ND280ND
2018ND280ND
2019ND520ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 1 ppb

The EWG Health Guideline of 1 ppb for perchlorate was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against hormone disruption.

ppb = parts per billion

All test results

Date Lab ID Result
2014-01-069588-040-0915ND
2014-01-069588-103-0910ND
2014-01-069588-108-0740ND
2014-01-209588-018-0640ND
2014-02-039588-103-0850ND
2014-02-039588-108-0735ND
2014-02-189588-018-0930ND
2014-03-039588-103-0905ND
2014-03-039588-108-0930ND
2014-03-179588-018-0950ND
2014-04-029588-007-0910ND
2014-04-029588-011-1000ND
2014-04-029588-013-1025ND
2014-04-029588-014-1100ND
2014-04-029588-040-0825ND
2014-04-029588-103-0810ND
2014-04-029588-108-0920ND
2014-04-219588-018-0825ND
2014-05-059588-103-1010ND
2014-05-059588-108-11055.70 ppb
2014-05-199588-018-0740ND
2014-06-039588-103-0740ND
2014-06-039588-108-0840ND
2014-06-169588-018-0809ND
2014-07-019588-040-0815ND
2014-07-019588-103-0837ND
2014-07-019588-108-0635ND
2014-07-219588-018-0830ND
2014-08-049588-103-1000ND
2014-08-049588-108-0730ND
2014-08-189588-018-0950ND
2014-09-039588-103-1050ND
2014-09-039588-108-0645ND
2014-09-159588-018-1125ND
2014-10-019588-040-0830ND
2014-10-019588-103-0915ND
2014-10-019588-108-0602ND
2014-10-209588-018-0910ND
2014-11-049588-040-0830ND
2014-11-049588-103-0905ND
2014-11-049588-108-0910ND
2014-11-179588-018-0910ND
2014-12-029588-040-0825ND
2014-12-029588-103-0905ND
2014-12-029588-108-0910ND
2014-12-109588-103-0720ND
2014-12-159588-018-0910ND
2015-01-069588-040-0830ND
2015-01-069588-103-0945ND
2015-01-069588-108-0710ND
2015-01-149588-103-1000ND
2015-01-209588-018-0935ND
2015-02-039588-040-1105ND
2015-02-039588-103-1010ND
2015-02-039588-108-0730ND
2015-02-179588-018-0735ND
2015-03-039588-040-0910ND
2015-03-039588-103-0920ND
2015-03-039588-108-0825ND
2015-03-169588-018-0705ND
2015-04-019588-040-0855ND
2015-04-019588-103-0915ND
2015-04-019588-108-0820ND
2015-04-089588-007-0900ND
2015-04-089588-013-1015ND
2015-04-089588-014-0950ND
2015-05-059588-040-0950ND
2015-05-059588-103-1010ND
2015-05-059588-108-0943ND
2015-06-029588-040-0825ND
2015-06-029588-103-0910ND
2015-06-029588-108-0905ND
2015-07-019588-040-0855ND
2015-07-019588-103-0825ND
2015-07-019588-108-0835ND
2015-07-079588-011-0925ND
2015-08-049588-040-0820ND
2015-08-049588-103-0800ND
2015-08-049588-108-07504.80 ppb
2015-09-019588-040-0925ND
2015-09-019588-103-0940ND
2015-09-019588-108-0810ND
2015-10-069588-040-0945ND
2015-10-069588-103-1010ND
2015-10-069588-108-1210ND
2015-11-039588-040-0820ND
2015-11-039588-103-0850ND
2015-11-039588-108-1105ND
2015-12-019588-040-0900ND
2015-12-019588-103-0925ND
2015-12-019588-108-1025ND
2015-12-109588-013-0915ND
2016-01-059588-007-1005ND
2016-01-059588-014-1045ND
2016-01-059588-040-0805ND
2016-01-059588-103-0840ND
2016-01-059588-108-0908ND
2016-02-109588-040-0830ND
2016-02-109588-103-0840ND
2016-02-109588-108-112013.0 ppb
2016-02-239588-040-0910ND
2016-02-239588-103-0920ND
2016-03-019588-011-0900ND
2016-03-019588-040-0835ND
2016-03-019588-103-0855ND
2016-03-019588-108-0725ND
2016-04-059588-007-0900ND
2016-04-059588-011-1045ND
2016-04-059588-013-1015ND
2016-04-059588-014-1000ND
2016-04-059588-040-0800ND
2016-04-059588-103-0815ND
2016-05-039588-040-0855ND
2016-05-039588-103-0846ND
2016-06-019588-040-0900ND
2016-06-019588-103-0845ND
2016-07-079588-040-0825ND
2016-07-079588-103-0840ND
2016-08-029588-040-1200ND
2016-08-029588-103-1220ND
2016-09-079588-040-0945ND
2016-09-079588-103-0840ND
2016-10-049588-040-1015ND
2016-10-049588-103-0945ND
2016-11-019588-040-0850ND
2016-11-019588-103-0920ND
2016-12-069588-040-1000ND
2016-12-069588-103-1030ND
2017-01-049588-040-0840ND
2017-01-049588-103-0855ND
2017-02-079588-040-0855ND
2017-02-079588-103-0830ND
2017-03-079588-040-0920ND
2017-03-079588-103-0855ND
2017-04-049588-007-0855ND
2017-04-049588-011-0955ND
2017-04-049588-013-0940ND
2017-04-049588-014-0930ND
2017-04-049588-040-0940ND
2017-04-049588-103-0910ND
2017-05-029588-040-0940ND
2017-05-029588-103-0925ND
2017-06-069588-040-0950ND
2017-06-069588-103-1005ND
2017-07-059588-040-0915ND
2017-07-059588-103-0930ND
2017-08-019588-040-0855ND
2017-08-019588-103-0830ND
2017-09-069588-040-0920ND
2017-09-069588-103-0845ND
2017-10-039588-040-0945ND
2017-10-039588-103-1000ND
2017-11-079588-040-0850ND
2017-11-079588-103-0935ND
2017-12-059588-040-0915ND
2017-12-059588-103-0850ND
2018-01-039588-040-0940ND
2018-01-039588-103-0855ND
2018-02-069588-040-0755ND
2018-02-069588-103-0810ND
2018-03-069588-040-0850ND
2018-03-069588-103-0840ND
2018-04-039588-007-0915ND
2018-04-039588-011-0925ND
2018-04-039588-013-1010ND
2018-04-039588-014-1025ND
2018-04-039588-040-0745ND
2018-04-039588-103-0735ND
2018-05-019588-040-0820ND
2018-05-019588-103-0800ND
2018-06-059588-040-0800ND
2018-06-059588-103-0810ND
2018-07-039588-040-0815ND
2018-07-039588-103-0805ND
2018-08-079588-040-0845ND
2018-08-079588-103-0855ND
2018-09-059588-040-0950ND
2018-09-059588-103-0920ND
2018-10-029588-040-0940ND
2018-10-029588-103-0855ND
2018-11-069588-040-0845ND
2018-11-069588-103-0800ND
2018-12-049588-040-1225ND
2018-12-049588-103-1150ND
2019-01-029588-040-0800ND
2019-01-029588-103-0820ND
2019-01-299588-102-0933ND
2019-01-299588-103-0936ND
2019-02-059588-040-0805ND
2019-02-059588-103-0840ND
2019-02-269588-102-0743ND
2019-02-269588-103-0746ND
2019-03-059588-040-0830ND
2019-03-059588-103-0900ND
2019-03-269588-102-0650ND
2019-03-269588-103-0655ND
2019-04-029588-007-0905ND
2019-04-029588-011-0910ND
2019-04-029588-013-0950ND
2019-04-029588-014-1010ND
2019-04-029588-040-0800ND
2019-04-029588-103-0916ND
2019-04-309588-102-0727ND
2019-04-309588-103-0730ND
2019-05-079588-040-0835ND
2019-05-079588-103-0853ND
2019-05-289588-102-0735ND
2019-05-289588-103-0732ND
2019-06-059588-040-0740ND
2019-06-059588-103-0805ND
2019-06-259588-102-0725ND
2019-06-259588-103-0722ND
2019-07-029588-040-0840ND
2019-07-029588-103-0900ND
2019-07-309588-102-0540ND
2019-07-309588-103-0543ND
2019-08-069588-040-0730ND
2019-08-069588-103-0950ND
2019-08-209588-102-0655ND
2019-08-209588-103-0700ND
2019-09-049588-040-0930ND
2019-09-049588-103-0955ND
2019-09-179588-102-0655ND
2019-09-179588-103-0700ND
2019-10-029588-040-0815ND
2019-10-029588-103-0840ND
2019-10-159588-102-0640ND
2019-10-159588-103-0637ND
2019-11-059588-040-0800ND
2019-11-059588-103-0820ND
2019-11-199588-102-0700ND
2019-11-199588-103-0705ND
2019-12-039588-040-0900ND
2019-12-039588-103-0915ND
2019-12-179588-102-0525ND
2019-12-179588-103-0530ND