Know Your Environment. Protect Your Health.

Selenium

Vista Hills Mutual Water Company

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.

 

8

Samples

5

Samples exceeding legal limit (MCL)

5

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201870.0 ppb21ND - 140.0 ppb
2019130.0 ppb11130.0 ppb
2020N/A00N/A
2021ND10ND
2022120.0 ppb11120.0 ppb
202362.0 ppb32ND - 130.0 ppb

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 Lab ID Result
2018-12-20CA4200848_005_005-201812201130ND
2018-12-20CA4200848_004_004-201812201140140.0 ppb
2019-05-07CA4200848_004_004-201905071030130.0 ppb
2021-03-29CA4200848_005_005-202103291230ND
2022-03-22CA4200848_004_004-202203221040120.0 ppb
2023-02-14CA4200848_004_004-20230214090056.0 ppb
2023-02-28CA4200848_005_005-202302280945ND
2023-02-28CA4200848_004_004-202302281010130.0 ppb