Chromium (total)

City of Madera

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	1.23 ppb	51	37	ND - 4.70 ppb
2015	ND	6	0	ND
2016	ND	8	0	ND
2017	ND	14	0	ND
2018	ND	2	0	ND
2019	ND	5	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
2014-02-28	5810-019-0842	ND
2014-02-28	5810-021-0825	ND
2014-02-28	5810-024-1018	ND
2014-02-28	5810-025-1128	ND
2014-02-28	5810-031-0931	ND
2014-03-20	A4C0742-37A	3.00 ppb
2014-03-20	A4C0742-25A	1.40 ppb
2014-03-20	A4C0742-27A	0.570 ppb
2014-03-20	A4C0742-21A	1.20 ppb
2014-03-20	A4C0742-23A	1.10 ppb
2014-03-20	A4C0742-35A	4.70 ppb
2014-03-20	A4C0742-33A	1.90 ppb
2014-03-20	A4C0742-11A	1.10 ppb
2014-03-20	A4C0742-39A	1.70 ppb
2014-03-20	A4C0742-29A	2.90 ppb
2014-03-20	A4C0742-31A	0.490 ppb
2014-03-20	A4C0742-05A	0.910 ppb
2014-03-20	A4C0742-07A	1.60 ppb
2014-03-20	A4C0742-01A	3.00 ppb
2014-03-20	A4C0742-03A	2.40 ppb
2014-03-20	A4C0742-15A	1.10 ppb
2014-03-20	A4C0742-19A	1.000 ppb
2014-03-20	A4C0742-17A	1.20 ppb
2014-03-20	A4C0742-09A	1.90 ppb
2014-05-29	5810-021-1301	ND
2014-05-29	5810-020-1112	ND
2014-05-29	5810-023-1211	ND
2014-05-29	5810-018-0919	ND
2014-05-29	5810-016-0903	ND
2014-05-29	5810-013-1236	ND
2014-05-29	5810-011-0837	ND
2014-09-25	A4I0631-34A	0.490 ppb
2014-09-25	A4I0631-13A	2.00 ppb
2014-09-25	A4I0631-10A	1.60 ppb
2014-09-25	A4I0631-16A	1.20 ppb
2014-09-25	A4I0631-25A	1.30 ppb
2014-09-25	A4I0631-37A	2.90 ppb
2014-09-25	A4I0631-31A	1.30 ppb
2014-09-25	A4I0631-28A	1.10 ppb
2014-09-25	A4I0631-46A	1.40 ppb
2014-09-25	A4I0631-43A	1.90 ppb
2014-09-25	A4I0631-40A	0.530 ppb
2014-09-25	A4I0631-49A	2.90 ppb
2014-09-25	A4I0631-51A	1.60 ppb
2014-09-25	A4I0631-22A	1.20 ppb
2014-09-25	A4I0631-07A	0.810 ppb
2014-09-25	A4I0631-04A	2.40 ppb
2014-09-25	A4I0631-01A	4.10 ppb
2014-09-25	A4I0631-19A	0.950 ppb
2014-11-20	5810-019-0852	ND
2014-11-20	5810-017-0934	ND
2015-02-19	5810-030-1118	ND
2015-02-19	5810-025-1014	ND
2015-02-19	5810-032-0925	ND
2015-02-19	5810-019-0856	ND
2015-05-21	5810-033-0817	ND
2015-11-19	5810-032-0922	ND
2016-02-18	5810-019-0922	ND
2016-02-18	5810-023-0937	ND
2016-02-18	5810-033-0850	ND
2016-02-18	5810-024-1130	ND
2016-02-18	5810-025-0903	ND
2016-02-18	5810-030-1048	ND
2016-05-31	5810-001-1042	ND
2016-08-25	5810-014-0957	ND
2017-02-16	9590-030-1057	ND
2017-02-16	9590-023-0832	ND
2017-02-16	9590-031-1008	ND
2017-02-16	9590-025-0949	ND
2017-02-16	9590-032-1035	ND
2017-05-25	9590-020-1100	ND
2017-05-25	9590-011-1425	ND
2017-05-25	9590-013-1403	ND
2017-05-25	9590-014-1347	ND
2017-05-25	9590-018-1129	ND
2017-05-25	9590-023-1316	ND
2017-05-25	9590-021-1150	ND
2017-11-16	9590-017-1005	ND
2017-11-16	9590-019-0941	ND
2018-05-24	5810-033-1010	ND
2018-12-06	5810-032-1405	ND
2019-02-22	5810-016-1310	ND
2019-02-22	5810-024-1200	ND
2019-02-22	5810-030-1115	ND
2019-06-14	5810-001-1133	ND
2019-12-06	5810-050-1330	ND