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EWG's Tap Water Database — 2021 UPDATE

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Arsenic

California Domestic Water Company

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

 

536

Samples

0

Samples exceeding legal limit (MCL)

270

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.771 ppb7525ND - 2.80 ppb
20150.654 ppb8523ND - 2.80 ppb
20161.46 ppb8952ND - 3.80 ppb
20170.663 ppb9426ND - 7.60 ppb
20181.26 ppb9754ND - 2.80 ppb
20192.23 ppb9690ND - 3.00 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
2014-01-063761-004-0801ND
2014-01-063761-005-1000ND
2014-01-063761-006-0929ND
2014-01-063761-007-0944ND
2014-01-063761-008-09052.30 ppb
2014-01-063761-009-0713ND
2014-02-033761-004-10532.50 ppb
2014-02-033761-005-0925ND
2014-02-033761-006-0851ND
2014-02-033761-007-0906ND
2014-02-033761-008-0815ND
2014-02-033761-009-07222.10 ppb
2014-02-033761-014-1035ND
2014-03-033761-004-0913ND
2014-03-033761-005-1005ND
2014-03-033761-006-08472.40 ppb
2014-03-033761-007-0930ND
2014-03-033761-008-0949ND
2014-03-033761-009-0750ND
2014-03-033761-014-1108ND
2014-03-219588-014-09102.20 ppb
2014-04-073761-004-08542.70 ppb
2014-04-073761-005-09392.70 ppb
2014-04-073761-006-09032.40 ppb
2014-04-073761-007-09212.10 ppb
2014-04-073761-008-08152.10 ppb
2014-04-073761-009-07352.80 ppb
2014-04-073761-014-10252.70 ppb
2014-04-099588-004-11202.30 ppb
2014-04-099588-005-1115ND
2014-04-099588-006-1140ND
2014-04-099588-007-1130ND
2014-04-099588-008-1150ND
2014-04-093761-020-07212.50 ppb
2014-05-053761-004-08342.10 ppb
2014-05-053761-005-0940ND
2014-05-053761-006-09122.10 ppb
2014-05-053761-007-0925ND
2014-05-053761-008-0820ND
2014-05-053761-009-0730ND
2014-05-053761-014-1017ND
2014-06-023761-004-0907ND
2014-06-023761-005-0920ND
2014-06-023761-006-0835ND
2014-06-023761-007-0849ND
2014-06-023761-008-0752ND
2014-06-023761-009-0715ND
2014-06-023761-014-1011ND
2014-07-073761-004-08222.40 ppb
2014-07-073761-005-09342.30 ppb
2014-07-073761-006-09002.20 ppb
2014-07-073761-007-09152.10 ppb
2014-07-073761-008-08072.20 ppb
2014-07-073761-009-07232.30 ppb
2014-07-073761-014-10452.10 ppb
2014-09-023761-004-0856ND
2014-09-023761-005-1006ND
2014-09-023761-006-0934ND
2014-09-023761-007-0949ND
2014-09-023761-008-0838ND
2014-09-023761-009-0750ND
2014-10-063761-004-08552.10 ppb
2014-10-063761-005-1024ND
2014-10-063761-006-0943ND
2014-10-063761-007-1000ND
2014-10-063761-008-08372.10 ppb
2014-10-063761-009-0750ND
2014-12-013761-004-0719ND
2014-12-013761-005-0816ND
2014-12-013761-006-0743ND
2014-12-013761-007-0755ND
2014-12-013761-008-0634ND
2014-12-013761-009-0555ND
2014-12-153761-014-0945ND
2014-12-163761-014-0905ND
2015-01-053761-004-0858ND
2015-01-053761-005-1038ND
2015-01-053761-006-1007ND
2015-01-053761-007-1021ND
2015-01-053761-008-0944ND
2015-01-053761-009-0739ND
2015-01-053761-014-1146ND
2015-02-023761-004-09282.10 ppb
2015-02-023761-005-1020ND
2015-02-023761-006-0945ND
2015-02-023761-007-1000ND
2015-02-023761-008-0848ND
2015-02-023761-009-0740ND
2015-02-023761-014-1121ND
2015-03-023761-004-0955ND
2015-03-023761-005-1119ND
2015-03-023761-006-1142ND
2015-03-023761-007-1130ND
2015-03-023761-008-0848ND
2015-03-023761-009-0753ND
2015-03-023761-014-1100ND
2015-04-063761-004-08502.70 ppb
2015-04-063761-005-05552.30 ppb
2015-04-063761-006-07432.40 ppb
2015-04-063761-007-07572.10 ppb
2015-04-063761-008-07302.60 ppb
2015-04-063761-009-05252.40 ppb
2015-04-063761-014-07002.50 ppb
2015-05-043761-004-0900ND
2015-05-043761-005-1021ND
2015-05-043761-006-0940ND
2015-05-043761-007-0957ND
2015-05-043761-008-0845ND
2015-05-043761-009-0740ND
2015-05-043761-014-1112ND
2015-06-013761-004-09102.80 ppb
2015-06-013761-005-09532.60 ppb
2015-06-013761-006-07222.60 ppb
2015-06-013761-007-09302.30 ppb
2015-06-013761-008-08282.80 ppb
2015-06-013761-009-07242.70 ppb
2015-06-013761-014-10422.70 ppb
2015-07-063761-004-0852ND
2015-07-063761-005-1006ND
2015-07-063761-006-0929ND
2015-07-063761-007-0945ND
2015-07-063761-008-0835ND
2015-07-063761-009-0723ND
2015-07-063761-014-1115ND
2015-08-033761-004-0904ND
2015-08-033761-005-1014ND
2015-08-033761-006-0940ND
2015-08-033761-007-0955ND
2015-08-033761-008-0847ND
2015-08-033761-009-0745ND
2015-08-033761-014-1030ND
2015-09-083761-004-0910ND
2015-09-083761-005-1025ND
2015-09-083761-006-0948ND
2015-09-083761-007-1006ND
2015-09-083761-008-0852ND
2015-09-083761-009-0740ND
2015-09-083761-014-1110ND
2015-10-053761-004-08092.60 ppb
2015-10-053761-005-09432.20 ppb
2015-10-053761-006-08402.30 ppb
2015-10-053761-007-0921ND
2015-10-053761-008-09022.20 ppb
2015-10-053761-009-07252.10 ppb
2015-10-053761-014-10292.10 ppb
2015-11-023761-004-09062.10 ppb
2015-11-023761-005-0957ND
2015-11-023761-006-0921ND
2015-11-023761-007-0934ND
2015-11-023761-008-0828ND
2015-11-023761-009-0735ND
2015-11-023761-014-1057ND
2015-11-199588-020-10552.40 ppb
2015-12-073761-004-0930ND
2015-12-073761-005-1018ND
2015-12-073761-006-0944ND
2015-12-073761-007-0959ND
2015-12-073761-008-0845ND
2015-12-073761-009-0750ND
2015-12-073761-014-1130ND
2016-01-043761-004-0745ND
2016-01-043761-006-0902ND
2016-01-043761-007-0920ND
2016-01-043761-008-0840ND
2016-01-043761-009-0721ND
2016-01-043761-014-0947ND
2016-01-123761-005-0847ND
2016-02-013761-004-0916ND
2016-02-013761-005-1043ND
2016-02-013761-006-0940ND
2016-02-013761-007-1002ND
2016-02-013761-008-1027ND
2016-02-013761-009-0737ND
2016-03-083761-004-08572.00 ppb
2016-03-083761-005-0940ND
2016-03-083761-006-10142.10 ppb
2016-03-083761-007-0958ND
2016-03-083761-008-08412.20 ppb
2016-03-083761-009-0730ND
2016-04-043761-004-09152.00 ppb
2016-04-043761-005-10302.10 ppb
2016-04-043761-006-10152.00 ppb
2016-04-043761-007-0958ND
2016-04-043761-008-0852ND
2016-04-043761-009-07452.00 ppb
2016-04-043761-014-11402.10 ppb
2016-05-023761-004-09062.50 ppb
2016-05-023761-005-10082.50 ppb
2016-05-023761-006-09402.30 ppb
2016-05-023761-007-0953ND
2016-05-023761-008-08512.50 ppb
2016-05-023761-009-07452.20 ppb
2016-05-023761-014-10222.70 ppb
2016-06-063761-004-08502.10 ppb
2016-06-063761-005-10142.50 ppb
2016-06-063761-006-09402.30 ppb
2016-06-063761-007-09552.20 ppb
2016-06-063761-008-08352.70 ppb
2016-06-063761-009-0755ND
2016-06-063761-014-11043.10 ppb
2016-06-063761-020-11452.60 ppb
2016-07-053761-004-0847ND
2016-07-053761-005-0925ND
2016-07-053761-006-0959ND
2016-07-053761-007-1015ND
2016-07-053761-008-0828ND
2016-07-053761-009-0730ND
2016-07-053761-014-1110ND
2016-07-053761-020-0940ND
2016-08-013761-004-08482.40 ppb
2016-08-013761-005-09252.20 ppb
2016-08-013761-006-10002.20 ppb
2016-08-013761-007-1011ND
2016-08-013761-008-08302.30 ppb
2016-08-013761-009-07232.20 ppb
2016-08-013761-014-10492.60 ppb
2016-08-013761-020-09402.30 ppb
2016-09-063761-004-09003.10 ppb
2016-09-063761-005-10212.80 ppb
2016-09-063761-006-09492.60 ppb
2016-09-063761-007-10062.40 ppb
2016-09-063761-008-08412.50 ppb
2016-09-063761-009-07552.60 ppb
2016-09-063761-014-11292.60 ppb
2016-09-063761-020-10392.60 ppb
2016-10-033761-004-08292.40 ppb
2016-10-033761-005-0948ND
2016-10-033761-006-0903ND
2016-10-033761-007-0924ND
2016-10-033761-008-0813ND
2016-10-033761-009-07292.20 ppb
2016-10-033761-014-1107ND
2016-10-033761-020-10042.00 ppb
2016-11-073761-004-08272.20 ppb
2016-11-073761-005-1116ND
2016-11-073761-006-09102.60 ppb
2016-11-073761-007-09352.40 ppb
2016-11-073761-008-08112.50 ppb
2016-11-073761-009-0730ND
2016-11-073761-014-11052.40 ppb
2016-11-073761-020-11252.60 ppb
2016-12-053761-004-08523.80 ppb
2016-12-053761-005-09443.30 ppb
2016-12-053761-006-09103.20 ppb
2016-12-053761-007-09253.00 ppb
2016-12-053761-009-07303.80 ppb
2016-12-053761-014-10352.80 ppb
2016-12-053761-020-10582.50 ppb
2016-12-073761-008-0825ND
2017-01-033761-004-0805ND
2017-01-033761-005-0927ND
2017-01-033761-006-0854ND
2017-01-033761-007-0905ND
2017-01-033761-008-0832ND
2017-01-033761-009-0712ND
2017-01-033761-014-0957ND
2017-01-033761-020-0941ND
2017-01-109588-014-09002.20 ppb
2017-02-083761-005-1012ND
2017-02-083761-006-0935ND
2017-02-083761-007-0951ND
2017-02-083761-008-0849ND
2017-02-083761-009-0736ND
2017-02-093761-020-0840ND
2017-03-063761-004-09022.00 ppb
2017-03-063761-005-1014ND
2017-03-063761-006-0933ND
2017-03-063761-007-0952ND
2017-03-063761-008-0840ND
2017-03-063761-009-0741ND
2017-03-063761-020-1026ND
2017-04-033761-004-09152.00 ppb
2017-04-033761-005-1015ND
2017-04-033761-006-0937ND
2017-04-033761-007-0954ND
2017-04-033761-008-0834ND
2017-04-033761-009-0748ND
2017-04-033761-014-1135ND
2017-04-033761-020-1031ND
2017-04-059588-004-09202.20 ppb
2017-04-059588-005-09052.00 ppb
2017-04-059588-006-09302.00 ppb
2017-04-059588-007-0940ND
2017-04-059588-008-0955ND
2017-05-083761-004-0853ND
2017-05-083761-005-0957ND
2017-05-083761-006-0928ND
2017-05-083761-007-0942ND
2017-05-083761-008-0840ND
2017-05-083761-009-0732ND
2017-05-083761-014-1023ND
2017-05-083761-020-1010ND
2017-06-053761-004-0905ND
2017-06-053761-005-1014ND
2017-06-053761-006-0942ND
2017-06-053761-007-0956ND
2017-06-053761-008-0848ND
2017-06-053761-009-0740ND
2017-06-053761-014-1112ND
2017-06-053761-020-1028ND
2017-07-053761-004-07132.00 ppb
2017-07-053761-005-0955ND
2017-07-053761-006-09187.60 ppb
2017-07-053761-007-09002.20 ppb
2017-07-053761-008-08432.70 ppb
2017-07-053761-009-0740ND
2017-07-053761-014-10452.50 ppb
2017-07-053761-020-09372.30 ppb
2017-07-243761-006-09552.40 ppb
2017-07-243761-006-10052.50 ppb
2017-08-073761-004-08402.50 ppb
2017-08-073761-005-10062.30 ppb
2017-08-073761-006-09252.20 ppb
2017-08-073761-007-0943ND
2017-08-073761-008-08192.20 ppb
2017-08-073761-009-07382.30 ppb
2017-08-073761-014-11362.10 ppb
2017-08-073761-020-10252.10 ppb
2017-09-263761-009-0930ND
2017-10-023761-004-08372.00 ppb
2017-10-023761-005-0919ND
2017-10-023761-006-1003ND
2017-10-023761-007-0940ND
2017-10-023761-008-0815ND
2017-10-023761-009-0729ND
2017-10-023761-014-1115ND
2017-10-023761-020-1020ND
2017-11-063761-004-0840ND
2017-11-063761-005-10102.00 ppb
2017-11-063761-006-0922ND
2017-11-063761-007-0935ND
2017-11-063761-008-0823ND
2017-11-063761-009-0728ND
2017-11-063761-014-11002.00 ppb
2017-11-063761-020-09552.00 ppb
2017-12-043761-004-08352.00 ppb
2017-12-043761-005-1012ND
2017-12-043761-006-0923ND
2017-12-043761-007-0937ND
2017-12-043761-008-0817ND
2017-12-043761-009-0738ND
2017-12-043761-014-1053ND
2017-12-043761-020-0956ND
2018-01-023761-004-08552.10 ppb
2018-01-023761-005-10252.00 ppb
2018-01-023761-006-0949ND
2018-01-023761-007-0935ND
2018-01-023761-008-0914ND
2018-01-023761-009-0736ND
2018-01-023761-014-1117ND
2018-01-023761-020-10082.00 ppb
2018-02-053761-004-0840ND
2018-02-053761-005-0912ND
2018-02-053761-006-1028ND
2018-02-053761-007-1018ND
2018-02-053761-008-1100ND
2018-02-053761-009-0722ND
2018-02-053761-014-0922ND
2018-02-053761-020-0856ND
2018-03-053761-004-08522.50 ppb
2018-03-053761-005-10022.20 ppb
2018-03-053761-006-09322.30 ppb
2018-03-053761-007-1027ND
2018-03-053761-008-08332.10 ppb
2018-03-053761-009-07482.20 ppb
2018-03-053761-014-11452.00 ppb
2018-03-053761-020-11382.30 ppb
2018-04-023761-004-0900ND
2018-04-023761-005-1038ND
2018-04-023761-006-0950ND
2018-04-023761-007-1018ND
2018-04-023761-008-0931ND
2018-04-023761-009-0757ND
2018-04-023761-014-1150ND
2018-04-023761-020-1054ND
2018-05-073761-004-0852ND
2018-05-073761-005-1013ND
2018-05-073761-006-0937ND
2018-05-073761-007-0922ND
2018-05-073761-008-0810ND
2018-05-073761-009-0720ND
2018-05-073761-014-1025ND
2018-05-073761-020-0954ND
2018-06-043761-004-0850ND
2018-06-043761-005-1021ND
2018-06-043761-006-0945ND
2018-06-043761-007-1002ND
2018-06-043761-008-0825ND
2018-06-043761-009-0738ND
2018-06-043761-014-1058ND
2018-06-043761-020-1035ND
2018-07-023761-004-09342.10 ppb
2018-07-023761-005-10232.10 ppb
2018-07-023761-006-09512.20 ppb
2018-07-023761-007-1004ND
2018-07-023761-008-08452.10 ppb
2018-07-023761-009-07582.00 ppb
2018-07-023761-014-11262.10 ppb
2018-07-023761-020-1039ND
2018-08-063761-004-09262.50 ppb
2018-08-063761-005-10552.40 ppb
2018-08-063761-006-10002.20 ppb
2018-08-063761-007-10162.00 ppb
2018-08-063761-008-08092.30 ppb
2018-08-063761-009-07282.30 ppb
2018-08-063761-014-10472.20 ppb
2018-08-063761-020-10352.50 ppb
2018-09-043761-004-09272.50 ppb
2018-09-043761-005-11062.30 ppb
2018-09-043761-006-10142.40 ppb
2018-09-043761-007-10282.00 ppb
2018-09-043761-008-08502.40 ppb
2018-09-043761-009-08102.40 ppb
2018-09-043761-014-12152.40 ppb
2018-09-043761-020-10492.60 ppb
2018-10-013761-005-10292.00 ppb
2018-10-013761-006-09582.20 ppb
2018-10-013761-007-0940ND
2018-10-013761-008-0822ND
2018-10-013761-009-07402.00 ppb
2018-10-013761-014-1127ND
2018-10-013761-020-10152.00 ppb
2018-10-043761-004-08152.00 ppb
2018-10-099588-020-09102.10 ppb
2018-11-053761-005-10172.40 ppb
2018-11-053761-006-09402.30 ppb
2018-11-053761-007-09532.10 ppb
2018-11-053761-008-08412.40 ppb
2018-11-053761-009-07502.50 ppb
2018-11-053761-014-11222.20 ppb
2018-11-053761-020-10352.50 ppb
2018-11-123761-004-09472.50 ppb
2018-12-033761-004-09142.80 ppb
2018-12-033761-005-10362.50 ppb
2018-12-033761-006-09442.50 ppb
2018-12-033761-008-08182.20 ppb
2018-12-033761-009-07302.50 ppb
2018-12-033761-014-11302.40 ppb
2018-12-033761-020-10192.60 ppb
2018-12-043761-007-08222.10 ppb
2019-01-083761-004-09182.60 ppb
2019-01-083761-005-10212.40 ppb
2019-01-083761-006-10022.40 ppb
2019-01-083761-007-09512.10 ppb
2019-01-083761-008-08562.00 ppb
2019-01-083761-009-07502.40 ppb
2019-01-083761-014-10442.20 ppb
2019-01-083761-020-10322.40 ppb
2019-02-043761-004-09152.30 ppb
2019-02-043761-005-10262.30 ppb
2019-02-043761-006-09502.30 ppb
2019-02-043761-007-0935ND
2019-02-043761-008-0825ND
2019-02-043761-009-07422.40 ppb
2019-02-043761-014-11352.00 ppb
2019-02-043761-020-10072.40 ppb
2019-03-043761-004-09422.80 ppb
2019-03-043761-005-10412.60 ppb
2019-03-043761-006-08342.70 ppb
2019-03-043761-007-08502.10 ppb
2019-03-043761-008-09102.20 ppb
2019-03-043761-009-07472.70 ppb
2019-03-043761-014-10512.50 ppb
2019-03-043761-020-09262.80 ppb
2019-04-013761-005-11312.30 ppb
2019-04-013761-006-09562.20 ppb
2019-04-013761-007-0941ND
2019-04-013761-008-08402.20 ppb
2019-04-013761-009-08142.30 ppb
2019-04-013761-014-11252.00 ppb
2019-04-013761-020-11152.30 ppb
2019-04-083761-004-09202.70 ppb
2019-05-063761-004-07522.60 ppb
2019-05-063761-005-07262.70 ppb
2019-05-063761-006-09272.30 ppb
2019-05-063761-007-09102.20 ppb
2019-05-063761-008-08492.10 ppb
2019-05-063761-009-06152.40 ppb
2019-05-063761-014-07142.40 ppb
2019-05-063761-020-07412.60 ppb
2019-06-033761-004-08502.70 ppb
2019-06-033761-005-10272.50 ppb
2019-06-033761-006-09542.40 ppb
2019-06-033761-007-09382.10 ppb
2019-06-033761-008-10192.10 ppb
2019-06-033761-009-07552.50 ppb
2019-06-033761-014-11112.40 ppb
2019-06-033761-020-10092.60 ppb
2019-07-013761-004-08532.60 ppb
2019-07-013761-005-09572.20 ppb
2019-07-013761-006-08252.30 ppb
2019-07-013761-007-08362.00 ppb
2019-07-013761-008-08012.30 ppb
2019-07-013761-009-07222.30 ppb
2019-07-013761-014-10232.30 ppb
2019-07-013761-020-09372.40 ppb
2019-08-053761-004-08582.50 ppb
2019-08-053761-005-10272.20 ppb
2019-08-053761-006-09552.20 ppb
2019-08-053761-007-0939ND
2019-08-053761-008-08272.30 ppb
2019-08-053761-009-07502.30 ppb
2019-08-053761-014-11332.50 ppb
2019-08-053761-020-10102.40 ppb
2019-09-033761-004-08262.60 ppb
2019-09-033761-005-06372.40 ppb
2019-09-033761-006-07112.40 ppb
2019-09-033761-007-07242.10 ppb
2019-09-033761-008-07502.40 ppb
2019-09-033761-009-09462.50 ppb
2019-09-033761-014-08452.40 ppb
2019-09-033761-020-06512.50 ppb
2019-10-073761-004-09192.40 ppb
2019-10-073761-005-10552.00 ppb
2019-10-073761-006-11182.00 ppb
2019-10-073761-007-1130ND
2019-10-073761-008-0843ND
2019-10-073761-009-08002.00 ppb
2019-10-073761-014-09582.10 ppb
2019-10-073761-020-10022.40 ppb
2019-11-043761-004-08543.00 ppb
2019-11-043761-005-10312.50 ppb
2019-11-043761-006-09352.40 ppb
2019-11-043761-007-09512.00 ppb
2019-11-043761-008-08222.30 ppb
2019-11-043761-009-07522.90 ppb
2019-11-043761-014-11122.60 ppb
2019-11-043761-020-10152.50 ppb
2019-12-023761-004-08532.70 ppb
2019-12-023761-005-10302.40 ppb
2019-12-023761-006-09312.40 ppb
2019-12-023761-007-09532.00 ppb
2019-12-023761-008-08252.30 ppb
2019-12-023761-009-07522.40 ppb
2019-12-023761-014-11062.40 ppb
2019-12-023761-020-10152.70 ppb