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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

Glendora Water Department

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

 

72

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND100ND
2015ND170ND
2016ND110ND
20170.364 ppb111ND - 4.00 ppb
2018ND110ND
2019ND120ND

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
2014-03-049588-009-1030ND
2014-03-049588-008-1020ND
2014-06-099588-009-0945ND
2014-09-099588-020-0915ND
2014-09-099588-015-1010ND
2014-09-099588-009-0925ND
2014-09-099588-007-1030ND
2014-09-179588-010-0950ND
2014-09-179588-006-1000ND
2014-12-089588-009-0920ND
2015-03-259588-002-0910ND
2015-03-259588-009-0920ND
2015-03-259588-008-0930ND
2015-06-059588-009-0810ND
2015-09-099588-020-0900ND
2015-09-099588-015-1025ND
2015-09-099588-007-0940ND
2015-09-099588-010-1010ND
2015-09-099588-009-0925ND
2015-09-099588-006-0955ND
2015-12-119588-020-1025ND
2015-12-119588-015-0950ND
2015-12-119588-010-0940ND
2015-12-119588-009-1015ND
2015-12-119588-002-1040ND
2015-12-119588-007-0930ND
2015-12-119588-006-0915ND
2016-03-039588-002-0930ND
2016-03-039588-009-0950ND
2016-03-039588-008-0940ND
2016-06-139588-009-0910ND
2016-09-089588-015-0955ND
2016-09-089588-007-0930ND
2016-09-089588-010-0940ND
2016-09-089588-020-1045ND
2016-09-089588-006-0920ND
2016-09-089588-009-1015ND
2016-12-069588-009-0905ND
2017-03-029588-002-0800ND
2017-03-029588-008-0810ND
2017-03-029588-009-08204.00 ppb
2017-06-139588-009-0930ND
2017-09-079588-006-0910ND
2017-09-079588-009-0850ND
2017-09-079588-020-0830ND
2017-09-079588-010-0930ND
2017-09-079588-007-0920ND
2017-09-079588-015-0940ND
2017-12-069588-009-0825ND
2018-03-079588-002-0840ND
2018-03-079588-008-0850ND
2018-03-079588-009-0900ND
2018-06-079588-009-0920ND
2018-09-149588-015-1050ND
2018-09-149588-010-1025ND
2018-09-149588-009-0925ND
2018-09-149588-020-0840ND
2018-09-149588-007-1005ND
2018-09-149588-006-0955ND
2018-12-049588-009-1015ND
2019-03-139588-008-0825ND
2019-03-139588-002-0815ND
2019-03-139588-020-0810ND
2019-03-139588-009-0830ND
2019-06-189588-009-0850ND
2019-09-199588-020-0730ND
2019-09-199588-006-0810ND
2019-09-199588-009-0910ND
2019-09-199588-010-0830ND
2019-09-199588-015-0840ND
2019-09-199588-007-0820ND
2019-12-049588-009-0730ND