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EWG's Tap Water Database — 2019 UPDATE

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Selenium

California Water Service Co-leona Valley

Selenium is an essential element in diets. But too much selenium can decrease thyroid hormone production and cause hair loss, skin lesions and brittle fingernails.

 

28

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND10ND
2013N/A00N/A
2014ND10ND
20151.06 ppb76ND - 1.51 ppb
2016ND60ND
2017ND130ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 30 ppb

The EWG Health Guideline of 30 ppb for selenium 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 hair loss and nail damage.

EPA Maximum Contaminant
Level (MCL) 50 ppb

The legal limit for selenium, established in 1991, was based on human epidemiological studies of populations exposed to naturally occurring selenium in drinking water. This limit does not include any additional consideration of children’s health.

ppb = parts per billion

All test results

Date Lab ID Result
2012-02-085810-006-1403ND
2014-05-065810-001-1356ND
2015-02-025810-006-1416ND
2015-05-135701-001-12100.943 ppb
2015-05-135701-006-12111.14 ppb
2015-05-135701-005-12051.51 ppb
2015-08-045701-001-13491.11 ppb
2015-08-045701-006-13471.39 ppb
2015-08-045701-005-13411.35 ppb
2016-05-035701-001-1245ND
2016-05-035701-005-1230ND
2016-05-035701-006-1237ND
2016-11-085701-005-1451ND
2016-11-085701-001-1429ND
2016-11-085701-006-1420ND
2017-02-075701-005-1120ND
2017-02-075701-006-1142ND
2017-02-075701-001-1137ND
2017-05-085810-001-1248ND
2017-05-095701-001-0946ND
2017-05-095701-006-0949ND
2017-05-095701-005-0940ND
2017-08-155701-005-1356ND
2017-08-155701-006-1405ND
2017-08-155701-001-1400ND
2017-11-085701-001-1723ND
2017-11-085701-005-1414ND
2017-12-125701-006-1531ND