Know Your Environment. Protect Your Health.

Selenium

Patterson Water System

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.

 

14

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND20ND
2019ND60ND
2020ND30ND
2021ND10ND
2022ND10ND
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 Lab ID Result
2018-01-2535370415002ND
2018-01-2535370415002ND
2019-01-1535442674001ND
2019-01-1535442674001ND
2019-07-2435484856001ND
2019-07-2435484856001ND
2019-10-2235507344001ND
2019-10-2235507344001ND
2020-01-0735522572001ND
2020-01-0735522572002ND
2020-04-14B2001727-001ND
2021-03-25B2101306-001ND
2022-01-06B2200050-001ND
2023-01-30B2300412-001ND