Know Your Environment. Protect Your Health.

Selenium

Mountain Regional Water Special Service 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.

 

33

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20182.00 ppb42ND - 7.40 ppb
20191.10 ppb129ND - 6.40 ppb
20200.200 ppb31ND - 0.600 ppb
2021ND10ND
20221.23 ppb125ND - 10.2 ppb
2023ND10ND

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

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 Result
2018-06-060.600 ppb
2018-06-207.40 ppb
2018-08-23ND
2018-09-05ND
2019-01-03ND
2019-01-030.600 ppb
2019-01-031.000 ppb
2019-01-036.40 ppb
2019-01-241.000 ppb
2019-01-241.30 ppb
2019-01-240.600 ppb
2019-02-251.30 ppb
2019-02-25ND
2019-02-250.500 ppb
2019-03-20ND
2019-11-140.500 ppb
2020-02-270.600 ppb
2020-07-14ND
2020-09-21ND
2021-12-08ND
2022-02-17ND
2022-02-172.70 ppb
2022-02-170.500 ppb
2022-02-170.700 ppb
2022-05-05ND
2022-05-050.700 ppb
2022-05-05ND
2022-08-04ND
2022-08-04ND
2022-08-0410.2 ppb
2022-09-07ND
2022-12-07ND
2023-12-11ND