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EWG's Tap Water Database — 2019 UPDATE

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Selenium

California Water Service Company - Dominguez

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.

 

22

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND10ND
20136.83 ppb61ND - 41.0 ppb
2014ND20ND
2015ND10ND
20162.00 ppb61ND - 12.0 ppb
2017ND60ND

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
2012-08-205810-018-1124ND
2013-03-135810-024-1047ND
2013-05-085810-036-1143ND
2013-06-185810-023-1312ND
2013-07-175810-050-144241.0 ppb
2013-09-195810-004-1430ND
2013-10-165810-022-1400ND
2014-08-275810-016-1310ND
2014-10-085810-019-1022ND
2015-03-259590-018-1355ND
2016-01-135810-023-1320ND
2016-03-239590-018-1340ND
2016-05-115810-036-1140ND
2016-07-135810-050-133512.0 ppb
2016-09-075810-004-1300ND
2016-12-289590-019-0930ND
2017-03-089590-019-1430ND
2017-08-235810-019-1100ND
2017-08-235810-016-1212ND
2017-10-119590-036-1335ND
2017-10-169590-805-1030ND
2017-12-265810-024-1315ND