EWG's Tap Water Database — 2021 UPDATE


Chromium (total)

City of Flagstaff

Chromium is a naturally occurring metal, but industrial uses can elevate its levels in water. One form, hexavalent chromium, causes cancer. Total chromium is not a good indicator of the amount of hexavalent chromium in drinking water.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20131.60 ppb18180.350 ppb - 2.70 ppb
20140.935 ppb2624ND - 2.20 ppb
20150.933 ppb63ND - 2.30 ppb
20160.800 ppb21ND - 1.60 ppb
20170.900 ppb32ND - 1.40 ppb
20182.00 ppb112.00 ppb
20191.60 ppb111.60 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EPA Maximum Contaminant
Level (MCL) 100 ppb

The legal limit for total chromium, established in 1991, was based on a 1958 toxicity study in laboratory animals, and applies to both the less-toxic trivalent chromium and the more-toxic hexavalent chromium forms of this compound. This limit does not protect against the risk of cancer from ingestion of hexavalent chromium.

ppb = parts per billion

All test results

Date Lab ID Result
2013-10-23201310240365AM0.350 ppb
2013-10-23201310240398AM1.10 ppb
2013-10-24201310250061AM1.50 ppb
2013-10-24201310250100AM1.70 ppb
2013-10-24201310250096AM2.20 ppb
2013-10-24201310250083AM0.880 ppb
2013-10-24201310250103AM1.80 ppb
2013-10-24201310250090AM1.90 ppb
2013-10-24201310250063AM2.70 ppb
2013-10-24201310250094AM1.80 ppb
2013-10-29201310300042AM1.40 ppb
2013-10-29201310300068AM1.90 ppb
2013-10-29201310300118AM2.10 ppb
2013-10-29201310300044AM0.620 ppb
2013-10-30201310310165AM2.20 ppb
2013-10-30201310310113AM1.80 ppb
2013-10-31201311010185AM1.90 ppb
2013-10-31201311010176AM1.000 ppb
2014-01-29201401300194AM0.370 ppb
2014-01-29201401300212AM0.530 ppb
2014-01-29201401300186AM1.20 ppb
2014-04-30201405020175AM0.990 ppb
2014-04-30201405020189AM1.60 ppb
2014-04-30201405020177AM0.820 ppb
2014-04-30201405020187AM1.50 ppb
2014-04-30201405020183AM0.710 ppb
2014-04-30201405020165AM1.60 ppb
2014-04-30201405020179AM0.870 ppb
2014-04-30201405020261AM0.610 ppb
2014-04-30201405020267AM1.60 ppb
2014-04-30201405020263AM0.630 ppb
2014-04-30201405020259AM1.40 ppb
2014-04-30201405020163AM0.550 ppb
2014-05-02201405060311AM2.20 ppb
2014-05-02201405060313AM0.630 ppb
2014-05-29201405300269AM1.80 ppb
2014-05-29201405300241AM0.970 ppb
2014-06-12201406130272AM1.000 ppb
2014-06-12201406130296AM1.50 ppb
2014-07-17201407180219AM0.400 ppb
2014-07-17201407180226AM0.500 ppb
2014-07-17201407180230AM0.330 ppb
2015-07-28201507210370I2.30 ppb
2015-07-30201507310184I1.000 ppb
2015-09-10201509120269I2.30 ppb
2016-08-17201608180220I1.60 ppb
2017-08-28201708290222I1.40 ppb
2017-08-28201708290221I1.30 ppb
2018-08-27201808280602I2.00 ppb
2019-04-29201904300311I1.60 ppb