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EWG's Tap Water Database — 2021 UPDATE

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Perchlorate

California Water Service (CWS) - Salinas

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

 

76

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND170ND
2015ND110ND
2016ND110ND
2017ND120ND
2018ND120ND
2019ND130ND

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
2014-01-079588-019-1453ND
2014-02-049588-104-1106ND
2014-04-089588-039-1138ND
2014-05-139588-102-1456ND
2014-05-139588-123-1020ND
2014-05-139588-103-1353ND
2014-06-179588-026-1236ND
2014-07-019588-104-1430ND
2014-08-269588-028-1335ND
2014-08-269588-029-1021ND
2014-08-269588-030-1150ND
2014-09-189588-131-1025ND
2014-09-189588-027-1044ND
2014-09-189588-046-1308ND
2014-11-129588-103-0937ND
2014-11-129588-102-1018ND
2014-11-129588-123-1405ND
2015-02-179588-104-1320ND
2015-02-189588-009-1355ND
2015-02-189588-106-1310ND
2015-03-119588-041-1025ND
2015-03-119588-037-1108ND
2015-04-219588-008-1348ND
2015-05-149588-102-1551ND
2015-05-149588-103-1500ND
2015-05-149588-123-1432ND
2015-06-249588-006-1443ND
2015-07-229588-005-1524ND
2016-01-269588-022-1125ND
2016-01-269588-020-1329ND
2016-01-279588-018-1016ND
2016-02-189588-103-1312ND
2016-02-299588-024-1357ND
2016-03-039588-015-1423ND
2016-04-149588-102-1405ND
2016-05-179588-017-1030ND
2016-06-229588-131-1109ND
2016-06-229588-023-1405ND
2016-12-079588-043-1440ND
2017-01-109588-019-1351ND
2017-01-199588-014-1045ND
2017-02-279588-027-1515ND
2017-03-029590-132-1050ND
2017-08-299588-029-1050ND
2017-08-299588-026-0933ND
2017-10-179588-030-1330ND
2017-11-029588-046-1328ND
2017-11-289588-046-1458ND
2017-11-289588-029-1108ND
2017-11-289588-026-1138ND
2017-12-215810-132-0925ND
2018-01-299588-006-1137ND
2018-02-159588-046-1029ND
2018-02-219588-104-1352ND
2018-03-149588-009-1300ND
2018-03-149588-037-1348ND
2018-04-249588-008-0924ND
2018-04-249588-041-0859ND
2018-05-099588-132-1110ND
2018-07-259588-005-1252ND
2018-07-259588-123-0902ND
2018-09-269588-106-0856ND
2018-09-269588-132-0930ND
2019-01-299588-024-1444ND
2019-01-299588-022-1109ND
2019-01-299588-020-1146ND
2019-01-299588-018-1352ND
2019-02-269588-103-0939ND
2019-03-149588-015-1440ND
2019-04-119588-023-1003ND
2019-05-239588-102-1318ND
2019-05-239588-132-0920ND
2019-05-239588-017-1109ND
2019-06-199590-131-0928ND
2019-09-129588-132-1438ND
2019-10-249588-043-1045ND