Chromium (hexavalent)

City of Napa

Chromium (hexavalent) is a carcinogen that commonly contaminates American drinking water. Chromium (hexavalent) in drinking water may be due to industrial pollution or natural occurrences in mineral deposits and groundwater. Read more about chromium (hexavalent).

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	0.108 ppb	12	12	0.0530 ppb - 0.230 ppb
2014	ND	3	0	ND
2015	ND	3	0	ND
2016	ND	1	0	ND
2017	ND	3	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

EWG Health Guideline 0.02 ppb

The EWG Health Guideline of 0.02 ppb for chromium (hexavalent) was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.

ppb = parts per billion

All test results

Date	Lab ID	Result
2013-01-09	1301175-001B	0.0700 ppb
2013-01-09	1301206-001B	0.130 ppb
2013-04-03	1304110-001B	0.230 ppb
2013-04-03	1304109-001B	0.170 ppb
2013-07-10	1307419-001B	0.130 ppb
2013-07-10	1307417-001B	0.0920 ppb
2013-07-10	1307418-001B	0.0970 ppb
2013-07-10	1307416-001B	0.0800 ppb
2013-10-03	1310113-001B	0.0530 ppb
2013-10-03	1310114-001B	0.0870 ppb
2013-10-03	1310112-001B	0.0830 ppb
2013-10-03	1310111-001B	0.0720 ppb
2014-07-09	1233-007-0925	ND
2014-07-09	1233-006-1245	ND
2014-07-09	1233-005-1145	ND
2015-07-21	1233-005-1120	ND
2015-07-21	1233-007-0940	ND
2015-07-21	1233-006-1415	ND
2016-07-27	1233-006-1545	ND
2017-07-20	1233-007-1050	ND
2017-07-20	1233-006-1330	ND
2017-09-13	1233-005-0840	ND
2018-07-11	1233-007-1200	ND
2018-07-11	1233-006-1015	ND
2019-07-10	1233-007-0830	ND
2019-07-10	1233-006-1200	ND