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EWG's Tap Water Database — 2019 UPDATE

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Selenium

Cross Valley Water District

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.

 

17

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND110ND
2013ND50ND
2014ND10ND
2015N/A00N/A
2016N/A00N/A
2017N/A00N/A

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
2012-12-1149250ND
2012-12-1149253ND
2012-12-1149252ND
2012-12-1149251ND
2012-12-1149249ND
2012-12-1149248ND
2012-12-1149247ND
2012-12-1149246ND
2012-12-1149245ND
2012-12-1149244ND
2012-12-1149243ND
2013-12-1053122ND
2013-12-1053121ND
2013-12-1053120ND
2013-12-1053119ND
2013-12-1053123ND
2014-10-1446279ND