Selenium

California Water Service (CWS) - Bakersfield

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.

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208

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	0.422 ppb	53	37	ND - 1.59 ppb
2015	0.133 ppb	35	8	ND - 1.17 ppb
2016	ND	39	0	ND
2017	ND	29	0	ND
2018	ND	29	0	ND
2019	ND	23	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
2014-01-06	5810-026-1415	ND
2014-01-14	5810-002-1008	ND
2014-02-04	5810-009-0931	ND
2014-03-04	5810-253-0810	ND
2014-05-05	5701-250-0958	0.741 ppb
2014-05-27	5701-250-0916	0.789 ppb
2014-06-02	5701-250-1048	0.388 ppb
2014-06-04	5701-131-0953	1.09 ppb
2014-06-05	5810-005-1016	ND
2014-06-09	5701-250-1017	0.702 ppb
2014-06-16	5701-250-0908	0.576 ppb
2014-06-25	5810-018-1018	ND
2014-06-25	5810-020-0934	ND
2014-06-30	5810-021-1025	ND
2014-06-30	5701-250-0916	0.243 ppb
2014-07-07	5806-011-1500	ND
2014-07-07	5701-055-1115	0.463 ppb
2014-07-07	5701-250-1050	1.59 ppb
2014-07-08	5701-005-1230	0.0170 ppb
2014-07-08	5701-091-1430	0.443 ppb
2014-07-10	5806-031-1345	ND
2014-07-14	5701-250-0909	0.369 ppb
2014-07-21	5701-250-1010	0.707 ppb
2014-07-28	5701-250-0952	0.609 ppb
2014-08-06	5806-024-1420	ND
2014-08-13	5806-015-1120	ND
2014-08-13	5701-250-1108	0.660 ppb
2014-08-18	5701-250-1042	0.818 ppb
2014-08-25	5701-250-1102	0.746 ppb
2014-09-02	5701-250-0553	0.612 ppb
2014-09-08	5701-250-1100	0.633 ppb
2014-09-10	5701-143-1350	0.293 ppb
2014-09-24	5701-143-1255	0.294 ppb
2014-09-29	5701-250-0922	0.688 ppb
2014-10-06	5701-006-1032	0.432 ppb
2014-10-06	5701-055-0914	0.432 ppb
2014-10-06	5701-250-0947	0.605 ppb
2014-10-07	5701-091-1000	0.559 ppb
2014-10-08	5701-050-0955	0.0650 ppb
2014-10-08	5806-050-1013	ND
2014-10-09	5806-004-1326	ND
2014-10-13	5701-250-0956	0.698 ppb
2014-10-20	5806-006-1125	ND
2014-10-20	5701-250-0858	0.589 ppb
2014-10-27	5701-250-0848	0.598 ppb
2014-11-03	5701-250-1202	0.603 ppb
2014-12-08	5701-143-1345	0.306 ppb
2014-12-08	5701-163-1420	1.46 ppb
2014-12-08	5701-250-0935	1.22 ppb
2014-12-09	5701-129-1425	0.175 ppb
2014-12-09	5701-131-1348	0.896 ppb
2014-12-15	5701-250-1031	0.258 ppb
2014-12-16	5810-003-2240	ND
2015-01-08	5701-072-1412	0.296 ppb
2015-01-20	5701-250-1420	0.437 ppb
2015-01-26	5701-250-1033	0.224 ppb
2015-02-17	5701-250-0915	0.403 ppb
2015-03-02	5701-143-1526	0.430 ppb
2015-03-02	5701-250-1306	1.17 ppb
2015-03-04	5806-051-1130	ND
2015-03-04	5806-072-1215	ND
2015-03-19	5806-253-0735	ND
2015-04-06	5701-250-0914	0.920 ppb
2015-04-20	5806-053-1307	ND
2015-04-21	5806-038-1450	ND
2015-05-11	5806-096-1025	ND
2015-05-11	5806-105-1331	ND
2015-05-11	5806-156-0938	ND
2015-06-16	5701-129-1258	0.788 ppb
2015-07-08	5806-059-1410	ND
2015-07-08	5806-068-1132	ND
2015-08-05	5806-099-1400	ND
2015-08-10	5806-098-1035	ND
2015-08-13	5806-160-0934	ND
2015-09-08	5701-250-0937	ND
2015-09-10	5806-092-1437	ND
2015-09-29	5701-091-1501	ND
2015-09-29	5701-129-1430	ND
2015-10-05	5806-079-1335	ND
2015-10-05	5806-091-1205	ND
2015-10-06	5806-058-1050	ND
2015-10-27	5806-056-1205	ND
2015-12-02	5701-129-1415	ND
2015-12-02	5701-131-1349	ND
2015-12-09	5806-106-1300	ND
2015-12-09	5806-163-1203	ND
2015-12-10	5806-094-1315	ND
2015-12-15	5806-108-1015	ND
2016-01-04	5806-106-0905	ND
2016-01-04	5806-107-0905	ND
2016-02-01	5701-250-1045	ND
2016-02-10	5806-122-1321	ND
2016-02-16	5701-250-0855	ND
2016-03-02	5701-143-2100	ND
2016-03-07	5701-250-1105	ND
2016-03-16	5806-253-1025	ND
2016-05-04	5806-124-1235	ND
2016-05-05	5806-118-1350	ND
2016-05-09	5701-250-1200	ND
2016-05-16	5701-250-1224	ND
2016-05-20	5806-110-1350	ND
2016-05-20	5806-126-1250	ND
2016-05-23	5701-250-1218	ND
2016-06-06	5701-250-1004	ND
2016-06-08	5806-148-1230	ND
2016-06-15	5806-131-1045	ND
2016-06-15	5701-131-1100	ND
2016-06-16	5806-055-1025	ND
2016-06-17	5806-151-1015	ND
2016-07-06	5701-250-0938	ND
2016-07-14	5806-109-1200	ND
2016-07-18	5701-055-1134	ND
2016-08-08	5806-149-1240	ND
2016-08-08	5806-154-0945	ND
2016-08-15	5806-125-1013	ND
2016-08-15	5701-250-1019	ND
2016-08-18	5806-069-1051	ND
2016-08-18	5806-150-1153	ND
2016-09-07	5806-119-1120	ND
2016-09-08	5806-052-1120	ND
2016-09-12	5806-143-1015	ND
2016-09-12	5806-146-1055	ND
2016-09-22	5806-117-0930	ND
2016-10-11	5701-129-1509	ND
2016-10-11	5701-129-1510	ND
2016-10-11	5806-129-1519	ND
2016-10-11	5701-250-1132	ND
2017-01-09	5701-250-0912	ND
2017-01-10	5806-002-1025	ND
2017-01-17	5701-250-0820	ND
2017-01-19	5806-026-0949	ND
2017-02-06	5701-250-0920	ND
2017-02-13	5701-250-0920	ND
2017-03-14	5806-253-0850	ND
2017-03-23	5806-021-0904	ND
2017-04-10	5806-009-1125	ND
2017-04-19	5806-004-1145	ND
2017-05-01	5701-250-0935	ND
2017-05-18	5701-250-0945	ND
2017-05-22	5701-250-1003	ND
2017-06-12	5806-050-1135	ND
2017-06-13	5701-005-1135	ND
2017-06-19	5806-018-0936	ND
2017-06-19	5701-250-1044	ND
2017-06-20	5806-005-1035	ND
2017-06-20	5806-015-1019	ND
2017-06-26	5806-006-0947	ND
2017-06-26	5701-250-1040	ND
2017-07-12	5806-003-0741	ND
2017-07-17	5701-250-0903	ND
2017-07-18	5806-031-1100	ND
2017-08-23	5806-024-1337	ND
2017-10-02	5701-250-0925	ND
2017-11-06	5806-011-1027	ND
2017-11-29	5701-250-1215	ND
2017-12-28	5806-020-1010	ND
2018-01-25	5701-267-1426	ND
2018-02-06	5701-250-1015	ND
2018-03-14	5806-051-1140	ND
2018-03-14	5806-072-1250	ND
2018-03-22	5806-253-0800	ND
2018-04-09	5701-250-0955	ND
2018-04-12	5701-267-1523	ND
2018-04-16	5806-156-1057	ND
2018-04-17	5806-053-1400	ND
2018-04-17	5806-105-0930	ND
2018-04-23	5806-094-1107	ND
2018-04-25	5806-096-0930	ND
2018-04-26	5806-038-1145	ND
2018-06-15	9590-026-0945	ND
2018-06-25	5701-091-0909	ND
2018-06-25	5701-250-1055	ND
2018-07-11	5806-068-1118	ND
2018-07-11	5806-092-1400	ND
2018-07-11	5806-106-1431	ND
2018-07-12	5806-056-1444	ND
2018-07-24	5806-059-1414	ND
2018-07-24	5806-091-0850	ND
2018-08-13	5806-099-0950	ND
2018-08-21	5806-098-0942	ND
2018-08-27	5806-160-1221	ND
2018-09-13	5806-058-0955	ND
2018-09-20	5806-069-1025	ND
2018-10-25	5806-058-1144	ND
2018-11-16	5806-048-1128	ND
2019-01-09	5806-107-1109	ND
2019-02-13	5806-122-1021	ND
2019-03-26	5806-253-1055	ND
2019-04-30	5701-267-0920	ND
2019-05-14	5806-125-0840	ND
2019-05-14	5806-126-0920	ND
2019-05-15	5806-118-1330	ND
2019-05-29	5806-110-1130	ND
2019-05-29	5806-124-0930	ND
2019-06-10	5806-148-1100	ND
2019-06-10	5806-151-1059	ND
2019-07-18	5806-109-0955	ND
2019-08-12	5806-117-1130	ND
2019-08-12	5806-149-1054	ND
2019-08-12	5806-154-1259	ND
2019-09-10	5806-146-0836	ND
2019-09-11	5806-143-0920	ND
2019-09-24	5806-055-1330	ND
2019-10-16	5806-052-1150	ND
2019-10-23	5701-018-0940	ND
2019-10-28	5806-150-1135	ND
2019-11-20	5806-108-0835	ND
2019-12-10	5806-119-0845	ND