Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Perchlorate

Tract 180 Mutual Water Company

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.

 

30

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND50ND
2015ND40ND
2016ND50ND
2017ND60ND
2018ND50ND
2019ND50ND

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
2014-01-279588-005-0953ND
2014-04-159588-005-1010ND
2014-04-159588-004-1035ND
2014-07-319588-005-1410ND
2014-12-159588-005-1003ND
2015-01-289588-005-0949ND
2015-04-309588-005-0952ND
2015-05-219588-004-0900ND
2015-08-079588-005-0928ND
2016-03-239588-005-0938ND
2016-06-209588-004-1005ND
2016-06-209588-005-0955ND
2016-07-199588-005-0949ND
2016-10-109588-005-0903ND
2017-01-179588-005-0947ND
2017-04-289588-004-1010ND
2017-04-289588-005-0945ND
2017-07-109588-005-0927ND
2017-07-109588-004-0943ND
2017-10-069588-005-0915ND
2018-01-169588-005-0955ND
2018-04-199588-005-0947ND
2018-04-199588-004-0959ND
2018-07-249588-005-0935ND
2018-10-169588-005-0940ND
2019-01-249588-005-1000ND
2019-05-149588-005-0850ND
2019-06-269588-004-1225ND
2019-08-239588-005-0940ND
2019-10-289588-005-0940ND