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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

Chuckawalla Valley/ironwood State Prison

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.

 

39

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND200ND
2015ND130ND
2016ND60ND
2017N/A00N/A
2018N/A00N/A
2019N/A00N/A

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
2014-02-054790-002-0945ND
2014-02-054790-006-0929ND
2014-04-094790-009-0910ND
2014-04-094790-002-0845ND
2014-04-094790-008-0655ND
2014-04-094790-003-0818ND
2014-04-094790-007-0925ND
2014-04-094790-006-0830ND
2014-07-234790-006-0809ND
2014-07-234790-002-0945ND
2014-07-234790-003-0738ND
2014-07-234790-007-0952ND
2014-07-234790-008-0650ND
2014-07-234790-009-0936ND
2014-11-264790-009-1002ND
2014-11-264790-006-0847ND
2014-11-264790-003-0840ND
2014-11-264790-007-1011ND
2014-11-264790-002-1018ND
2014-11-264790-008-0745ND
2015-02-114790-009-0946ND
2015-04-154790-007-0947ND
2015-04-154790-002-0952ND
2015-04-154790-003-0823ND
2015-04-154790-006-0838ND
2015-04-154790-008-0742ND
2015-04-154790-009-0943ND
2015-10-149469-008-0806ND
2015-10-149469-007-1020ND
2015-10-149469-006-0903ND
2015-10-149469-003-1000ND
2015-10-149469-002-1026ND
2015-10-149469-009-1015ND
2016-02-039469-007-1023ND
2016-02-039469-009-0901ND
2016-02-039469-006-0923ND
2016-02-039469-008-0804ND
2016-02-039469-003-0915ND
2016-02-039469-002-1005ND