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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

East Valley Water District

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

 

51

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND90ND
2015ND20ND
2016ND180ND
2017ND10ND
2018ND50ND
2019ND160ND

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
2014-01-293761-054-1445ND
2014-02-043761-054-0905ND
2014-02-113761-054-0920ND
2014-02-193761-054-1030ND
2014-04-093761-054-1315ND
2014-04-183761-054-1119ND
2014-04-223761-054-1320ND
2014-06-183761-002-0940ND
2014-08-153761-036-0800ND
2015-06-233761-002-0940ND
2015-06-233761-036-0845ND
2016-03-173761-036-0923ND
2016-06-073761-055-0855ND
2016-06-073761-053-0810ND
2016-06-073761-042-0810ND
2016-06-073761-039-0825ND
2016-06-073761-015-0850ND
2016-06-073761-031-0845ND
2016-06-073761-024-0925ND
2016-06-073761-016-1000ND
2016-06-073761-017-0831ND
2016-06-073761-020-0841ND
2016-06-073761-021-0900ND
2016-06-083761-046-0710ND
2016-06-093761-036-0000ND
2016-06-143761-032-0745ND
2016-06-143761-023-0955ND
2016-06-143761-019-0816ND
2016-10-263761-033-0737ND
2017-06-063761-036-1021ND
2018-06-053761-017-0740ND
2018-06-053761-020-0800ND
2018-06-073761-036-0833ND
2018-06-193761-019-0800ND
2018-06-263761-023-0747ND
2019-06-043761-017-0933ND
2019-06-043761-033-0734ND
2019-06-043761-020-0841ND
2019-06-073761-036-1040ND
2019-06-113761-024-0850ND
2019-06-113761-042-0743ND
2019-06-113761-021-0836ND
2019-06-113761-032-0752ND
2019-06-113761-023-0810ND
2019-06-183761-053-0734ND
2019-06-183761-019-0808ND
2019-06-183761-031-0744ND
2019-06-183761-015-0715ND
2019-06-213761-055-0000ND
2019-06-213761-046-0811ND
2019-06-213761-039-0823ND