Chromium (total)

City of Concord

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	0.154 ppb	11	5	ND - 0.470 ppb
2015	0.270 ppb	5	3	ND - 0.690 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
2014-01-15	8221-011514-EP2I	ND
2014-01-15	8221-011514-EP1I	ND
2014-04-14	35134253001AM	ND
2014-04-14	35134253003AM	ND
2014-04-14	35134253005AM	0.210 ppb
2014-07-15	35146563005AM	0.290 ppb
2014-07-15	35146563001AM	ND
2014-07-15	35146563003AM	0.310 ppb
2014-10-14	35159414005AM	0.470 ppb
2014-10-14	35159414001AM	ND
2014-10-14	35159414003AM	0.410 ppb
2015-01-14		ND
2015-01-14		ND
2015-01-21	35172516005AM	0.420 ppb
2015-01-21	35172516003AM	0.690 ppb
2015-01-26	35172850001AM	0.240 ppb
2016-01-26	3391004	ND
2016-01-26	3391024	ND
2017-01-23	3625442	ND
2017-01-23	3625437	ND
2018-01-30	3861466	ND
2018-01-30	3861485	ND
2019-02-04	4187566-1	ND
2019-02-04	4187622-1	ND