Chromium (total)

City of Denton

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	0.500 ppb	14	2	ND - 3.50 ppb
2015	0.113 ppb	6	1	ND - 0.680 ppb
2016	ND	2	0	ND
2017	1.50 ppb	2	2	1.40 ppb - 1.60 ppb
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
2014-03-24	Q1409211003	3.50 ppb
2014-03-24	Q1409211004	3.50 ppb
2014-04-14	Q1411646009	ND
2014-04-14	Q1411646011	ND
2014-04-14	Q1411646005	ND
2014-04-14	Q1411646001	ND
2014-07-09	Q1426463001	ND
2014-07-09	Q1426463011	ND
2014-07-09	Q1426463009	ND
2014-07-09	Q1426463005	ND
2014-10-14	Q1452213001	ND
2014-10-14	Q1452213009	ND
2014-10-14	Q1452213011	ND
2014-10-14	Q1452213005	ND
2015-01-20	Q1501500005	ND
2015-01-20	Q1501500009	ND
2015-01-20	Q1501500011	ND
2015-01-20	Q1501500001	ND
2015-03-23	Q1510645002	0.680 ppb
2015-06-22	Q1523209011	ND
2016-02-09	Q1605594004	ND
2016-02-09	Q1605594003	ND
2017-01-31	Q1704367014	1.60 ppb
2017-01-31	Q1704367013	1.40 ppb
2018-01-30	Q1803503002	ND
2018-01-30	Q1803503011	ND
2019-03-12	Q1910518013	ND
2019-03-12	Q1910518004	ND