Chromium (total)

City of Aurora

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.

MORE ABOUT THIS CONTAMINANT

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	0.661 ppb	11	10	ND - 2.00 ppb
2015	0.416 ppb	9	5	ND - 1.000 ppb
2016	2.00 ppb	1	1	2.00 ppb
2017	2.50 ppb	1	1	2.50 ppb
2018	1.60 ppb	1	1	1.60 ppb
2019	1.14 ppb	10	7	ND - 2.23 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	Result
2014-01-07	2.00 ppb
2014-08-18	1.40 ppb
2014-08-18	0.210 ppb
2014-08-18	ND
2014-08-18	1.30 ppb
2014-08-18	0.220 ppb
2014-08-18	0.220 ppb
2014-11-17	0.230 ppb
2014-11-17	0.210 ppb
2014-11-17	0.620 ppb
2014-11-17	0.860 ppb
2015-01-06	ND
2015-02-18	0.260 ppb
2015-02-18	0.850 ppb
2015-02-18	0.670 ppb
2015-02-18	ND
2015-05-13	0.960 ppb
2015-05-13	ND
2015-05-13	ND
2015-05-13	1.000 ppb
2016-07-12	2.00 ppb
2017-01-03	2.50 ppb
2018-01-02	1.60 ppb
2019-01-08	2.11 ppb
2019-01-08	1.39 ppb
2019-04-02	1.59 ppb
2019-04-02	2.23 ppb
2019-07-02	ND
2019-07-02	ND
2019-07-02	1.25 ppb
2019-10-01	ND
2019-10-01	1.15 ppb
2019-10-01	1.65 ppb