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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

Garden City

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

 

75

Samples

0

Samples exceeding legal limit (MCL)

26

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20142.05 ppb117ND - 4.60 ppb
20151.18 ppb166ND - 3.90 ppb
20161.13 ppb167ND - 3.50 ppb
20170.440 ppb103ND - 2.00 ppb
20180.186 ppb71ND - 1.30 ppb
20190.247 ppb153ND - 1.40 ppb

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
2014-03-211403F69-0014.50 ppb
2014-04-171404D70-0034.60 ppb
2014-08-151408B39-005-PRI4.20 ppb
2014-08-151408B39-003-PRIND
2014-08-151408B39-004-PRIND
2014-08-151408B39-001-PRIND
2014-08-181408C56-004-PRIND
2014-08-181408C56-002-PRI1.70 ppb
2014-08-181408C56-001-PRI1.60 ppb
2014-08-181408C56-003-PRI2.00 ppb
2014-10-151410A44-003-POCS3.90 ppb
2015-02-111502658-0033.90 ppb
2015-05-211505G04-0023.90 ppb
2015-08-051508347-002-PRIND
2015-08-051508347-005-PRIND
2015-08-051508347-003-SEC3.20 ppb
2015-08-051508347-001ND
2015-08-051508347-003-PRI3.20 ppb
2015-08-051508347-004-PRI1.40 ppb
2015-08-061508491-004-PRIND
2015-08-061508491-002-PRIND
2015-08-061508491-007-PRIND
2015-08-061508491-001-PRIND
2015-08-071508632-001-PRIND
2015-08-071508632-002-PRIND
2015-10-141510B25-0103.30 ppb
2015-10-281510L96-003-PRIND
2016-01-201601D70-001-POCS3.40 ppb
2016-04-131604C90-001-POCS3.50 ppb
2016-04-201604J20-001-POCS1.70 ppb
2016-07-061607432-001-PRIND
2016-07-151607D32-006-POCS3.30 ppb
2016-08-171608H35-001-PRIND
2016-08-171608H35-002-PRIND
2016-09-091609665-001-PRIND
2016-09-091609665-002-PRIND
2016-09-121609776-002-PRI3.30 ppb
2016-09-141609B78-003-PRIND
2016-09-211609I88-003-PRI1.30 ppb
2016-09-211609I88-001-PRI1.60 ppb
2016-09-231609L06-003-PRIND
2016-09-231609L06-001-PRIND
2016-10-20702600001ND
2017-04-187016226004ND
2017-07-0770234710052.00 ppb
2017-10-047031902006ND
2017-10-0470319030041.20 ppb
2017-10-0470319030031.20 ppb
2017-10-137032857002ND
2017-10-13703857003ND
2017-10-137032857001ND
2017-10-267034156001ND
2017-10-267034156002ND
2018-06-227055925002ND
2018-10-117067661002-PRIND
2018-10-117067661001-PRIND
2018-10-157067953002ND
2018-10-157067953001-PRIND
2018-10-247068920001-PRIND
2018-11-2170718200061.30 ppb
2019-05-097088902003-SECND
2019-05-097088902001-SECND
2019-08-07701002840041.000 ppb
2019-08-0770100284003-PRIND
2019-08-0770100284002ND
2019-08-0870100531003ND
2019-08-08701005310011.30 ppb
2019-08-08701005310021.40 ppb
2019-08-0970100701003-PRIND
2019-08-0970100701002-PRIND
2019-08-0970100701001-PRIND
2019-08-1970101923002ND
2019-08-1970101923001-PRIND
2019-08-2170102243001-PRIND
2019-08-2170102243002-PRIND