Selenium

City of Gainesville

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.

MORE ABOUT THIS CONTAMINANT

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2013	N/A	0	0	N/A
2014	1.69 ppb	1	1	1.69 ppb
2015	ND	1	0	ND
2016	0.600 ppb	6	2	ND - 2.00 ppb
2017	ND	6	0	ND
2018	ND	1	0	ND
2019	ND	6	0	ND

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
2014-02-26	Q1406422032	1.69 ppb
2015-03-30	Q1511751002	ND
2016-01-14	Q1601618008	ND
2016-01-14	Q1601618007	ND
2016-01-14	Q1601618006	ND
2016-01-14	Q1601618005	1.60 ppb
2016-01-14	Q1601618004	2.00 ppb
2016-05-03	Q1617287001	ND
2017-02-13	Q1706172021	ND
2017-02-13	Q1706172022	ND
2017-02-13	Q1706172052	ND
2017-02-13	Q1706172051	ND
2017-02-13	Q1706172030	ND
2017-02-13	Q1706172050	ND
2018-01-31	Q1804068016	ND
2019-02-26	Q1908409011	ND
2019-02-26	Q1908409010	ND
2019-02-26	Q1908409009	ND
2019-02-26	Q1908409008	ND
2019-06-19	Q1939089005	ND
2019-06-19	Q1939089006	ND