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EWG's Tap Water Database — 2019 UPDATE

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Selenium

North Penn Water Authority

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.

 

26

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND120ND
2013N/A00N/A
2014N/A00N/A
2015ND130ND
2016ND10ND
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
2012-05-0712050555ND
2012-05-0712050555ND
2012-05-0712050555ND
2012-05-0712050555ND
2012-05-0712050555ND
2012-05-1412051179ND
2012-05-1412051179ND
2012-05-1412051179ND
2012-05-1412051179ND
2012-05-1412051179ND
2012-05-1412051179ND
2012-07-2312072182ND
2015-01-1912287656ND
2015-01-1912287645ND
2015-01-1912287623ND
2015-01-1912287634ND
2015-02-0912401685ND
2015-02-0912401674ND
2015-02-0912401663ND
2015-03-0912515592ND
2015-03-0912515603ND
2015-04-2012633595ND
2015-05-1912750092ND
2015-05-1912750093ND
2015-12-0913633909ND
2016-08-2314907942ND