Arsenic

City of Davis

Arsenic is a potent carcinogen and common contaminant in drinking water. Arsenic causes thousands of cases of cancer each year in the U.S. Click here to read more about arsenic.

MORE ABOUT THIS CONTAMINANT

119

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	1.96 ppb	21	12	ND - 7.30 ppb
2015	2.23 ppb	25	16	ND - 6.40 ppb
2016	2.58 ppb	24	13	ND - 7.50 ppb
2017	2.81 ppb	17	12	ND - 7.30 ppb
2018	4.73 ppb	17	17	2.50 ppb - 7.40 ppb
2019	4.72 ppb	15	15	2.80 ppb - 7.40 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.004 ppb

The EWG Health Guideline of 0.004 ppb for arsenic 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 cancer.

EPA Maximum Contaminant
Level (MCL) 10 ppb

The legal limit for arsenic, established in 2001, was based on costs for arsenic removal, as calculated at the time that the standard was set. This limit does not fully protect against the risk of cancer due to arsenic exposure.

ppb = parts per billion

All test results

Date	Lab ID	Result
2014-08-05	5810-002-0822	ND
2014-08-05	5810-004-0810	2.20 ppb
2014-08-05	5810-006-0837	ND
2014-08-05	5810-009-1120	ND
2014-08-05	5810-010-0918	ND
2014-08-05	5810-014-0950	ND
2014-08-05	5810-015-1036	ND
2014-08-05	5810-016-0853	2.80 ppb
2014-08-05	5810-017-0909	4.40 ppb
2014-08-05	5810-018-0753	ND
2014-08-05	5810-019-0737	ND
2014-08-05	5810-020-0657	2.20 ppb
2014-08-05	5810-023-0720	2.70 ppb
2014-08-05	5810-024-1025	3.40 ppb
2014-08-05	5810-025-1000	4.20 ppb
2014-08-05	5810-026-1014	ND
2014-08-05	5810-030-1059	2.20 ppb
2014-08-05	5810-052-0935	7.30 ppb
2014-11-04	5810-017-0809	2.90 ppb
2014-11-04	5810-025-0914	3.90 ppb
2014-11-04	5810-052-0856	2.90 ppb
2015-02-10	5810-017-0910	2.80 ppb
2015-02-10	5810-025-0702	2.30 ppb
2015-02-10	5810-052-0713	4.00 ppb
2015-05-05	5810-017-0724	2.60 ppb
2015-05-05	5810-025-0757	4.30 ppb
2015-05-05	5810-052-0600	5.60 ppb
2015-07-07	5810-002-1333	ND
2015-07-07	5810-004-1253	ND
2015-07-07	5810-006-1115	ND
2015-07-07	5810-010-1148	2.60 ppb
2015-07-07	5810-015-1321	ND
2015-07-07	5810-016-0957	ND
2015-07-07	5810-017-1030	3.70 ppb
2015-07-07	5810-018-0721	ND
2015-07-07	5810-020-0757	ND
2015-07-07	5810-023-0904	ND
2015-07-07	5810-024-1120	2.50 ppb
2015-07-07	5810-025-0832	2.50 ppb
2015-07-07	5810-026-1041	ND
2015-07-07	5810-030-0919	2.30 ppb
2015-07-07	5810-052-0648	4.20 ppb
2015-07-21	5810-009-0747	2.30 ppb
2015-10-06	5810-017-0803	3.90 ppb
2015-10-06	5810-025-0902	3.70 ppb
2015-10-06	5810-052-0842	6.40 ppb
2016-01-11	5810-017-0910	4.70 ppb
2016-01-11	5810-025-0934	5.40 ppb
2016-01-11	5810-052-0921	7.50 ppb
2016-01-26	5810-019-1005	2.40 ppb
2016-04-06	5810-017-0902	5.80 ppb
2016-04-06	5810-025-0800	6.20 ppb
2016-04-06	5810-052-0700	6.30 ppb
2016-07-13	5810-030-0844	3.40 ppb
2016-07-20	5810-026-0757	3.80 ppb
2016-07-20	5810-052-0843	6.00 ppb
2016-07-27	5810-004-0750	ND
2016-07-27	5810-006-0817	ND
2016-07-27	5810-010-1021	ND
2016-07-27	5810-015-0943	ND
2016-07-27	5810-016-0846	ND
2016-07-27	5810-017-1027	2.30 ppb
2016-07-27	5810-018-0803	ND
2016-07-27	5810-019-0922	ND
2016-07-27	5810-020-0836	ND
2016-07-27	5810-023-0855	ND
2016-07-27	5810-024-0955	ND
2016-07-27	5810-025-1009	3.90 ppb
2016-10-26	5810-017-1015	ND
2016-10-26	5810-025-1055	4.20 ppb
2017-02-15	5810-025-0920	3.40 ppb
2017-03-20	5810-057-1120	3.40 ppb
2017-05-03	5810-025-0925	3.10 ppb
2017-05-03	5810-052-0728	2.80 ppb
2017-06-14	5810-057-0820	4.50 ppb
2017-08-02	5810-006-0859	ND
2017-08-02	5810-018-0843	ND
2017-08-02	5810-019-0823	ND
2017-08-02	5810-020-0805	2.00 ppb
2017-08-02	5810-025-0925	3.40 ppb
2017-08-02	5810-026-0943	ND
2017-08-02	5810-052-1115	4.70 ppb
2017-08-03	5810-030-0625	ND
2017-09-20	5810-057-0910	4.40 ppb
2017-11-14	5810-025-1044	4.00 ppb
2017-11-14	5810-052-0937	7.30 ppb
2017-12-12	5810-057-0735	4.80 ppb
2018-02-14	5810-057-0925	4.50 ppb
2018-02-21	5810-025-0846	4.70 ppb
2018-02-21	5810-052-0651	7.40 ppb
2018-04-18	5810-028-0855	5.10 ppb
2018-05-09	5810-025-0838	4.60 ppb
2018-05-09	5810-052-0812	6.60 ppb
2018-08-15	5810-018-0819	3.10 ppb
2018-08-15	5810-019-0902	2.50 ppb
2018-08-15	5810-020-1001	3.10 ppb
2018-08-15	5810-025-0755	4.20 ppb
2018-08-15	5810-028-0720	4.00 ppb
2018-08-15	5810-030-0640	3.70 ppb
2018-08-15	5810-052-0930	7.10 ppb
2018-08-15	5810-057-0840	5.40 ppb
2018-11-07	5810-025-0752	3.90 ppb
2018-11-07	5810-028-0818	4.60 ppb
2018-11-07	5810-052-0735	5.90 ppb
2019-02-06	5810-025-0755	4.70 ppb
2019-02-06	5810-028-0820	4.50 ppb
2019-02-06	5810-052-0859	6.60 ppb
2019-05-08	5810-025-0819	4.10 ppb
2019-05-08	5810-052-1130	5.70 ppb
2019-08-07	9590-025-1102	4.60 ppb
2019-08-07	9590-028-1033	4.10 ppb
2019-08-07	9590-030-1008	4.10 ppb
2019-08-07	9590-052-1134	7.40 ppb
2019-08-07	9590-057-1200	5.10 ppb
2019-08-08	9590-018-1010	3.40 ppb
2019-08-08	9590-019-1033	2.80 ppb
2019-08-08	9590-020-1103	3.60 ppb
2019-11-05	9590-025-0944	4.80 ppb
2019-11-05	9590-052-1003	5.30 ppb