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EWG's Tap Water Database — 2021 UPDATE

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Arsenic

Denver Water Board

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

 

121

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
2014ND240ND
2015ND30ND
2016ND30ND
20170.106 ppb314ND - 1.20 ppb
2018ND300ND
2019ND300ND

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 Result
2014-04-08ND
2014-04-15ND
2014-04-22ND
2014-05-13ND
2014-05-13ND
2014-05-27ND
2014-06-17ND
2014-06-17ND
2014-06-17ND
2014-07-22ND
2014-07-22ND
2014-07-22ND
2014-08-12ND
2014-08-12ND
2014-08-12ND
2014-09-16ND
2014-09-16ND
2014-09-16ND
2014-10-21ND
2014-10-21ND
2014-11-12ND
2014-11-12ND
2014-12-02ND
2014-12-02ND
2015-08-04ND
2015-08-04ND
2015-08-04ND
2016-03-22ND
2016-03-22ND
2016-03-22ND
2017-01-17ND
2017-02-14ND
2017-02-14ND
2017-02-21ND
2017-03-13ND
2017-03-14ND
2017-04-25ND
2017-04-25ND
2017-05-15ND
2017-05-16ND
2017-05-16ND
2017-06-20ND
2017-06-20ND
2017-06-20ND
2017-07-18ND
2017-07-18ND
2017-08-22ND
2017-08-220.600 ppb
2017-08-22ND
2017-09-190.800 ppb
2017-09-191.20 ppb
2017-09-190.700 ppb
2017-10-17ND
2017-10-17ND
2017-10-17ND
2017-11-15ND
2017-11-15ND
2017-11-15ND
2017-12-19ND
2017-12-19ND
2017-12-19ND
2018-01-23ND
2018-01-23ND
2018-01-23ND
2018-02-13ND
2018-02-13ND
2018-03-20ND
2018-03-20ND
2018-04-17ND
2018-04-17ND
2018-04-24ND
2018-05-15ND
2018-05-15ND
2018-05-15ND
2018-06-19ND
2018-06-19ND
2018-06-19ND
2018-07-02ND
2018-07-02ND
2018-07-02ND
2018-08-07ND
2018-08-07ND
2018-08-07ND
2018-09-04ND
2018-09-04ND
2018-09-04ND
2018-10-02ND
2018-10-02ND
2018-10-23ND
2018-11-06ND
2018-11-06ND
2019-01-08ND
2019-01-08ND
2019-02-05ND
2019-02-05ND
2019-03-05ND
2019-03-05ND
2019-04-02ND
2019-04-02ND
2019-05-07ND
2019-05-07ND
2019-05-07ND
2019-06-04ND
2019-06-04ND
2019-06-04ND
2019-07-02ND
2019-07-02ND
2019-07-02ND
2019-08-06ND
2019-08-06ND
2019-08-06ND
2019-09-10ND
2019-09-10ND
2019-09-10ND
2019-10-08ND
2019-10-08ND
2019-10-08ND
2019-11-05ND
2019-11-05ND
2019-12-03ND
2019-12-03ND