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EWG's Tap Water Database — 2021 UPDATE

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Arsenic

Golden State Water Company (GSWC) - Southwest

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.

 

27

Samples

0

Samples exceeding legal limit (MCL)

4

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.371 ppb142ND - 2.60 ppb
2015N/A00N/A
2016N/A00N/A
20170.408 ppb132ND - 3.00 ppb
2018N/A00N/A
2019N/A00N/A

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
2014-05-132706-005-13142.60 ppb
2014-05-132706-070-13252.60 ppb
2014-05-132706-069-1127ND
2014-05-132706-064-1104ND
2014-05-132706-062-1017ND
2014-05-132706-061-1037ND
2014-05-132706-045-1204ND
2014-05-132706-043-1140ND
2014-05-132706-039-1221ND
2014-05-132706-038-0811ND
2014-05-132706-037-0837ND
2014-05-132706-036-0953ND
2014-05-132706-011-1356ND
2014-05-132706-010-0915ND
2017-02-239590-073-0924ND
2017-03-239590-011-1240ND
2017-03-299590-005-13453.00 ppb
2017-03-299590-070-13072.30 ppb
2017-03-299590-045-1145ND
2017-03-299590-039-1235ND
2017-03-299590-036-0915ND
2017-03-299590-010-1050ND
2017-03-309590-069-0845ND
2017-03-309590-043-0920ND
2017-03-309590-038-0725ND
2017-03-309590-037-0653ND
2017-04-139590-064-0754ND