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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

New York American Water - Sea Cliff

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.

 

80

Samples

0

Samples exceeding legal limit (MCL)

23

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20141.06 ppb1410ND - 1.70 ppb
20150.575 ppb126ND - 1.30 ppb
20160.346 ppb134ND - 1.20 ppb
2017ND130ND
20180.357 ppb144ND - 1.40 ppb
2019ND140ND

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
2014-03-061403383-001-POCS1.40 ppb
2014-03-181403C48-0011.60 ppb
2014-04-021404187-001-POCS1.60 ppb
2014-04-0204187-001-POCS1.60 ppb
2014-04-081404620-0011.50 ppb
2014-04-281404J91-0011.70 ppb
2014-05-071405474-001-POCS1.50 ppb
2014-05-201405E50-0011.40 ppb
2014-06-101406727-001-PRI1.50 ppb
2014-06-101406727-003-PRIND
2014-08-251408H14-001ND
2014-09-081409505-001-POCSND
2014-10-071410466-001-POCS1.10 ppb
2014-12-021412131-001-POCSND
2015-01-281501G11-0011.10 ppb
2015-02-041502203-001-POCS1.10 ppb
2015-03-031503130-001-POCS1.20 ppb
2015-04-081504541-001-POCS1.30 ppb
2015-05-071505554-001-POCS1.10 ppb
2015-06-151506B92-003-PRIND
2015-06-151506B92-001-PRIND
2015-07-081507488-0011.10 ppb
2015-08-051508310-001 POCSND
2015-10-061510358-001ND
2015-11-091511661-001ND
2015-12-021512184-001ND
2016-01-261601G80-001ND
2016-03-011603105-001ND
2016-04-061604546-001ND
2016-05-031605198-001ND
2016-06-081606789-0031.10 ppb
2016-06-211606L00-002 PRIND
2016-06-211606L00-001 PRIND
2016-07-061607433-003ND
2016-08-021608166-005ND
2016-09-071609450-0031.20 ppb
2016-10-06701359004ND
2016-11-027035230011.20 ppb
2016-12-067061150011.000 ppb
2017-01-04708295001ND
2017-02-077010806001ND
2017-03-077012749001ND
2017-04-047014847001ND
2017-05-027017429001ND
2017-05-167018727004ND
2017-06-067020461001ND
2017-07-057023139001ND
2017-08-017025787002ND
2017-09-057028919001-PRIND
2017-10-027031587001ND
2017-11-077035028001ND
2017-12-057037238001ND
2018-01-0970399100011.10 ppb
2018-02-087042474001ND
2018-03-0670445730011.10 ppb
2018-04-037047080001ND
2018-05-0170501340011.40 ppb
2018-06-0570537540011.40 ppb
2018-07-037057077003ND
2018-08-027060231003ND
2018-09-047063575001ND
2018-10-027066538001ND
2018-11-287072200001ND
2018-12-197074419001ND
2018-12-267074879001-PRIND
2018-12-267074879002-PRIND
2019-01-157076606003ND
2019-01-157076606001ND
2019-02-057078364002ND
2019-03-197082788001ND
2019-04-027084234001ND
2019-05-147089462001ND
2019-06-037091767001ND
2019-07-097096833001ND
2019-08-057099950001ND
2019-09-0370103523001ND
2019-09-2470106031001-PRIND
2019-09-2470106031002-PRIND
2019-10-2370109466001ND
2019-11-2570113095001ND