Chromium (total)

Centennial Water and Sanitation District

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.

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Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2013	0.0929 ppb	14	4	ND - 0.570 ppb
2014	ND	7	0	ND
2015	ND	2	0	ND
2016	1.67 ppb	3	3	1.000 ppb - 2.00 ppb
2017	0.333 ppb	3	1	ND - 1.000 ppb
2018	ND	3	0	ND
2019	1.000 ppb	3	3	1.000 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
2013-05-13	0.280 ppb
2013-05-13	ND
2013-05-13	0.230 ppb
2013-06-12	ND
2013-06-12	ND
2013-06-26	0.220 ppb
2013-08-12	ND
2013-08-12	ND
2013-08-12	ND
2013-08-12	ND
2013-11-11	ND
2013-11-11	0.570 ppb
2013-11-11	ND
2013-12-03	ND
2014-02-18	ND
2014-02-18	ND
2014-02-18	ND
2014-02-18	ND
2014-07-23	ND
2014-07-29	ND
2014-08-12	ND
2015-07-27	ND
2015-08-12	ND
2016-07-27	1.000 ppb
2016-07-27	2.00 ppb
2016-08-17	2.00 ppb
2017-01-25	ND
2017-01-25	ND
2017-08-15	1.000 ppb
2018-09-04	ND
2018-09-04	ND
2018-09-04	ND
2019-07-31	1.000 ppb
2019-07-31	1.000 ppb
2019-07-31	1.000 ppb