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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

Golden State Water Company - Ojai

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.

 

20

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND70ND
2015ND20ND
2016N/A00N/A
2017ND50ND
2018ND60ND
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
2014-01-222706-010-0905ND
2014-01-222706-007-0925ND
2014-01-222706-004-0855ND
2014-01-222706-002-0915ND
2014-01-222706-003-0845ND
2014-02-052706-015-0930ND
2014-05-072706-015-0845ND
2015-03-112706-010-1055ND
2015-09-022706-010-0852ND
2017-02-149590-003-1041ND
2017-02-149590-004-0953ND
2017-02-149590-007-1020ND
2017-02-149590-002-1001ND
2017-02-149590-015-0936ND
2018-01-255867-010-1134ND
2018-01-255867-015-1153ND
2018-01-255867-007-1102ND
2018-01-255867-004-1205ND
2018-01-255867-003-1033ND
2018-01-255867-002-1119ND