EWG's Tap Water Database — 2021 UPDATE


Chromium (hexavalent)

City of Flagstaff

Chromium (hexavalent) is a carcinogen that commonly contaminates American drinking water. Chromium (hexavalent) in drinking water may be due to industrial pollution or natural occurrences in mineral deposits and groundwater. Read more about chromium (hexavalent).





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20131.65 ppb18180.410 ppb - 2.20 ppb
20141.08 ppb25250.0500 ppb - 2.10 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.02 ppb

The EWG Health Guideline of 0.02 ppb for chromium (hexavalent) 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.

ppb = parts per billion

All test results

Date Lab ID Result
2013-10-23201310240398AM1.20 ppb
2013-10-23201310240365AM0.410 ppb
2013-10-24201310250063AM1.80 ppb
2013-10-24201310250096AM2.20 ppb
2013-10-24201310250100AM1.70 ppb
2013-10-24201310250103AM1.80 ppb
2013-10-24201310250090AM1.80 ppb
2013-10-24201310250094AM1.90 ppb
2013-10-24201310250083AM0.880 ppb
2013-10-24201310250061AM1.80 ppb
2013-10-29201310300118AM2.20 ppb
2013-10-29201310300068AM2.10 ppb
2013-10-29201310300044AM0.620 ppb
2013-10-29201310300042AM1.60 ppb
2013-10-30201310310165AM2.10 ppb
2013-10-30201310310113AM2.10 ppb
2013-10-31201311010176AM1.20 ppb
2013-10-31201311010185AM2.20 ppb
2014-01-29201401300212AM0.580 ppb
2014-01-29201401300194AM0.390 ppb
2014-01-29201401300186AM1.30 ppb
2014-04-30201405020261AM0.620 ppb
2014-04-30201405020175AM0.950 ppb
2014-04-30201405020163AM0.510 ppb
2014-04-30201405020179AM0.850 ppb
2014-04-30201405020267AM1.80 ppb
2014-04-30201405020263AM0.620 ppb
2014-04-30201405020259AM1.60 ppb
2014-04-30201405020165AM1.60 ppb
2014-04-30201405020189AM1.80 ppb
2014-04-30201405020177AM0.790 ppb
2014-04-30201405020187AM1.70 ppb
2014-04-30201405020183AM0.710 ppb
2014-05-02201405060311AM2.10 ppb
2014-05-02201405060313AM0.640 ppb
2014-05-29201405300269AM1.80 ppb
2014-05-29201405300241AM0.860 ppb
2014-06-12201406130272AM1.000 ppb
2014-06-12201406130296AM1.90 ppb
2014-07-17201407180221AM0.0500 ppb
2014-07-17201407180226AM0.470 ppb
2014-07-24201407250210AM0.390 ppb
2014-08-06201408070500AM1.90 ppb