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EWG's Tap Water Database — 2021 UPDATE

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Selenium

California Water Service - Bear Gulch

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.

MORE ABOUT THIS CONTAMINANT

 

23

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
2014N/A00N/A
2015N/A00N/A
2016ND70ND
2017ND90ND
2018ND40ND
2019ND30ND

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
2016-02-165810-002-1045ND
2016-02-165810-907-1135ND
2016-02-225701-002-1312ND
2016-03-075701-002-1459ND
2016-04-185701-002-1123ND
2016-05-025701-002-1328ND
2016-06-305701-909-0849ND
2017-01-175701-002-1023ND
2017-02-085701-002-0939ND
2017-02-155810-002-1243ND
2017-02-155810-907-1256ND
2017-03-065701-002-1339ND
2017-05-105701-002-1335ND
2017-06-195701-002-1338ND
2017-11-275701-002-1112ND
2017-12-065701-002-1335ND
2018-01-085701-002-0931ND
2018-02-065701-002-1039ND
2018-02-075810-002-1229ND
2018-02-075810-907-1213ND
2019-01-305701-002-1241ND
2019-02-205810-907-1344ND
2019-02-265810-002-1416ND