Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Arsenic

United Water Cons District

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

 

89

Samples

0

Samples exceeding legal limit (MCL)

49

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.375 ppb162ND - 3.00 ppb
20151.38 ppb166ND - 5.00 ppb
20162.00 ppb129ND - 5.00 ppb
20171.87 ppb1510ND - 8.00 ppb
20182.15 ppb1311ND - 6.00 ppb
20191.59 ppb1711ND - 5.00 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
2014-04-095867-001-11133.00 ppb
2014-04-095867-004-0733ND
2014-04-095867-007-08033.00 ppb
2014-04-095867-008-0848ND
2014-04-095867-009-0903ND
2014-04-095867-010-1100ND
2014-04-095867-013-1025ND
2014-04-095867-017-0917ND
2014-10-155867-010-0828ND
2014-10-155867-009-0845ND
2014-10-155867-001-1100ND
2014-10-155867-013-1000ND
2014-10-155867-008-0804ND
2014-10-155867-007-0748ND
2014-10-155867-004-0715ND
2014-12-235867-017-0730ND
2015-02-175867-026-0905ND
2015-04-145867-013-10504.00 ppb
2015-04-145867-017-0812ND
2015-04-145867-010-0842ND
2015-04-145867-008-0900ND
2015-04-145867-026-0728ND
2015-04-145867-007-07053.00 ppb
2015-04-145867-004-07423.00 ppb
2015-04-145867-001-10405.00 ppb
2015-10-195867-026-0720ND
2015-10-195867-017-1006ND
2015-10-195867-010-0920ND
2015-10-195867-001-11004.00 ppb
2015-10-195867-004-07383.00 ppb
2015-10-195867-007-0750ND
2015-10-195867-008-1050ND
2016-04-055867-007-07162.00 ppb
2016-04-055867-001-09523.00 ppb
2016-04-055867-004-07463.00 ppb
2016-04-055867-026-08002.00 ppb
2016-04-055867-017-0854ND
2016-04-055867-010-09062.00 ppb
2016-04-055867-008-0816ND
2016-10-275867-010-08102.00 ppb
2016-10-275867-001-09125.00 ppb
2016-10-275867-026-07482.00 ppb
2016-10-275867-007-07343.00 ppb
2016-10-275867-017-0800ND
2017-04-195867-010-1038ND
2017-04-195867-004-0836ND
2017-04-195867-026-0914ND
2017-04-195867-008-0816ND
2017-04-195867-007-08002.00 ppb
2017-04-195867-017-0926ND
2017-04-195867-001-10523.00 ppb
2017-10-315867-010-07442.00 ppb
2017-10-315867-004-07163.00 ppb
2017-10-315867-027-09542.00 ppb
2017-10-315867-026-08202.00 ppb
2017-10-315867-008-11242.00 ppb
2017-10-315867-007-09242.00 ppb
2017-10-315867-001-12308.00 ppb
2017-10-315867-017-12002.00 ppb
2018-04-175867-001-09566.00 ppb
2018-04-175867-007-10402.00 ppb
2018-04-175867-010-08562.00 ppb
2018-04-175867-026-08202.00 ppb
2018-04-175867-017-0843ND
2018-04-175867-027-09182.00 ppb
2018-04-175867-004-07492.00 ppb
2018-10-095867-007-08402.00 ppb
2018-10-095867-017-0927ND
2018-10-095867-026-09082.00 ppb
2018-10-095867-004-08182.00 ppb
2018-10-095867-027-10162.00 ppb
2018-11-215867-013-08284.00 ppb
2019-04-105867-004-08222.00 ppb
2019-04-105867-026-0908ND
2019-04-105867-001-07454.00 ppb
2019-04-105867-008-1040ND
2019-04-105867-027-1026ND
2019-04-105867-017-09242.00 ppb
2019-04-105867-007-0853ND
2019-04-105867-013-1014ND
2019-10-085867-004-08352.00 ppb
2019-10-085867-027-10502.00 ppb
2019-10-085867-026-08552.00 ppb
2019-10-085867-008-10102.00 ppb
2019-10-085867-007-09592.00 ppb
2019-10-085867-001-07555.00 ppb
2019-10-085867-010-10252.00 ppb
2019-10-085867-017-0945ND
2019-10-085867-013-08132.00 ppb