Arsenic

Lafayette Utilities Water System

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

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	2.00 ppb	2	2	2.00 ppb
2015	0.551 ppb	30	12	ND - 2.00 ppb
2016	0.791 ppb	14	12	ND - 1.60 ppb
2017	0.500 ppb	4	2	ND - 1.000 ppb
2018	0.500 ppb	20	8	ND - 2.00 ppb
2019	ND	16	0	ND

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
2014-11-03	AD99266	2.00 ppb
2014-11-03	AD99266	2.00 ppb
2015-02-23	35176705001	ND
2015-02-23	35176705001	ND
2015-06-08	35192506001	1.000 ppb
2015-06-08	35192506001	1.000 ppb
2015-07-27	35199527004	0.570 ppb
2015-07-27	35199527001	ND
2015-07-27	35199527002	ND
2015-07-27	35199527003	1.60 ppb
2015-07-27	35199527004	0.570 ppb
2015-07-27	35199527005	ND
2015-07-27	35199527003	1.60 ppb
2015-07-27	35199527002	ND
2015-07-27	35199527001	ND
2015-07-27	35199527005	ND
2015-08-17	35203222004	ND
2015-08-17	35203222003	ND
2015-08-17	35203222002	ND
2015-08-17	35203222001	1.20 ppb
2015-08-17	35203222005	ND
2015-08-17	35203222005	ND
2015-08-17	35203222004	ND
2015-08-17	35203222003	ND
2015-08-17	35203222002	ND
2015-08-17	35203222001	1.20 ppb
2015-11-30	35218949003	ND
2015-11-30	35218949003	ND
2015-11-30	35218949004	2.00 ppb
2015-11-30	35218949005	1.90 ppb
2015-11-30	35218949004	2.00 ppb
2015-11-30	35218949005	1.90 ppb
2016-03-14	35234164005	ND
2016-03-14	35234164005	ND
2016-03-21	35235879005	0.770 ppb
2016-03-21	35235879005	0.770 ppb
2016-08-08	35259258005	0.540 ppb
2016-08-08	35259258005	0.540 ppb
2016-08-15	35260131002	1.60 ppb
2016-08-15	35260131003	0.780 ppb
2016-08-15	35260131004	0.940 ppb
2016-08-15	35260131004	0.940 ppb
2016-08-15	35260131001	0.910 ppb
2016-08-15	35260131003	0.780 ppb
2016-08-15	35260131002	1.60 ppb
2016-08-15	35260131001	0.910 ppb
2017-09-25	AE18498	1.000 ppb
2017-09-25	AE18498	1.000 ppb
2017-11-27	AE20051	ND
2017-11-27	AE20051	ND
2018-03-05	AE20858	ND
2018-03-05	AE20861	ND
2018-03-05	AE20864	ND
2018-03-05	AE20867	2.00 ppb
2018-03-05	AE20861	ND
2018-03-05	AE20864	ND
2018-03-05	AE20867	2.00 ppb
2018-03-05	AE20855	1.000 ppb
2018-03-05	AE20858	ND
2018-03-05	AE20855	1.000 ppb
2018-04-30	AE21621	ND
2018-04-30	AE21621	ND
2018-05-14	AE21747	ND
2018-05-14	AE21747	ND
2018-06-18	AE21918	ND
2018-06-18	AE21918	ND
2018-06-19	AE21921	1.000 ppb
2018-06-19	AE21921	1.000 ppb
2018-06-19	AE21924	1.000 ppb
2018-06-19	AE21924	1.000 ppb
2019-01-14	B1900254-002	ND
2019-01-14	B1900254-001	ND
2019-01-14	35442886001	ND
2019-01-14	35442886001	ND
2019-01-14	B1900254-001	ND
2019-01-14	B1900254-002	ND
2019-08-12	B1903460-001	ND
2019-08-12	B1903460-005	ND
2019-08-12	B1903460-004	ND
2019-08-12	B1903460-003	ND
2019-08-12	B1903460-002	ND
2019-08-12	B1903460-001	ND
2019-08-12	B1903460-005	ND
2019-08-12	B1903460-004	ND
2019-08-12	B1903460-003	ND
2019-08-12	B1903460-002	ND