Chromium (total)

City of Mission

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
2014	0.197 ppb	9	2	ND - 1.46 ppb
2015	1.29 ppb	10	5	ND - 10.1 ppb
2016	ND	2	0	ND
2017	ND	2	0	ND
2018	ND	2	0	ND
2019	ND	2	0	ND

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
2014-03-20	AC47793	ND
2014-05-05	AC52837	ND
2014-09-22	Q1446419001	ND
2014-09-22	Q1446419007	1.46 ppb
2014-09-22	Q1446419005	ND
2014-09-22	Q1446419003	ND
2014-12-10	Q1459434001	ND
2014-12-10	Q1459434007	0.312 ppb
2014-12-10	Q1459434003	ND
2015-02-05	AC79411	ND
2015-03-16	Q1509429003	ND
2015-03-16	Q1509429001	ND
2015-03-16	Q1509429005	ND
2015-03-16	Q1509429007	10.1 ppb
2015-05-06	AC90667	ND
2015-06-18	Q1522917001	0.240 ppb
2015-06-18	Q1522917003	0.224 ppb
2015-06-18	Q1522917007	2.04 ppb
2015-06-18	Q1522917005	0.284 ppb
2016-02-02	AD21367	ND
2016-02-02	AD21366	ND
2017-03-08	AD74279	ND
2017-04-25	AD81411	ND
2018-03-05	AE16875	ND
2018-03-05	AE16876	ND
2019-01-15	AE50045	ND
2019-09-17	AE83774	ND