Know Your Environment. Protect Your Health.

Selenium

Gowc North 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.

 

29

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018N/A00N/A
2019N/A00N/A
20208.50 ppb118.50 ppb
202110.1 ppb338.20 ppb - 13.0 ppb
20223.66 ppb136ND - 13.0 ppb
20230.442 ppb121ND - 5.30 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
2020-12-02B2006458-0018.50 ppb
2021-02-01B2100475-00113.0 ppb
2021-05-03B2102123-0018.20 ppb
2021-05-03B2102123-0029.20 ppb
2022-02-09B2200572-0027.10 ppb
2022-02-09B2200572-001ND
2022-02-15B2200664-00213.0 ppb
2022-02-15B2200664-0018.30 ppb
2022-04-04B2201638-0015.60 ppb
2022-04-04B2201638-002ND
2022-09-27B2204850-001ND
2022-10-24B2205110-002ND
2022-10-24B2205110-001ND
2022-11-22B2205635-0047.10 ppb
2022-11-22B2205635-0036.50 ppb
2022-11-22B2205635-002ND
2022-11-22B2205635-001ND
2023-01-23B2300295-006ND
2023-01-23B2300295-005ND
2023-01-23B2300295-004ND
2023-01-23B2300295-003ND
2023-01-23B2300295-001ND
2023-01-27B2300529-001ND
2023-02-22B2300746-001ND
2023-04-03B2301548-002ND
2023-04-03B2301548-001ND
2023-07-10B2302776-0045.30 ppb
2023-07-10B2302776-002ND
2023-07-10B2302776-001ND