Chromium (total)

City of Midlothian

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
2013	0.164 ppb	8	3	ND - 0.867 ppb
2014	4.20 ppb	2	2	3.90 ppb - 4.50 ppb
2015	0.645 ppb	2	2	0.450 ppb - 0.840 ppb
2016	0.820 ppb	2	2	0.650 ppb - 0.990 ppb
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
2013-01-15	1301337-003A	ND
2013-01-15	1301337-001A	ND
2013-04-17	1304611-003A	ND
2013-04-17	1304611-001A	ND
2013-07-24	Q1304313001	0.208 ppb
2013-07-24	Q1304313003	0.235 ppb
2013-10-02	Q1308558001	0.867 ppb
2013-10-02	Q1308558003	ND
2014-03-31	Q1410082010	3.90 ppb
2014-03-31	Q1410082011	4.50 ppb
2015-03-19	Q1510436002	0.450 ppb
2015-06-01	Q1519779002	0.840 ppb
2016-03-23	Q1611951001	0.990 ppb
2016-05-18	Q1619797004	0.650 ppb
2017-07-11	Q1728156001	ND
2017-09-28	Q1747556004	ND
2018-01-25	Q1802981005	ND
2018-01-25	Q1802981004	ND
2019-02-12	Q1906277007	ND
2019-02-12	Q1906277001	ND