Know Your Environment. Protect Your Health.

Chromium (total)

Humboldt, City of

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.

 

6

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20181.40 ppb111.40 ppb
2019ND10ND
20202.30 ppb112.30 ppb
2021ND10ND
20222.00 ppb112.00 ppb
20231.20 ppb111.20 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

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
2018-04-169385411.40 ppb
2019-04-081139841ND
2020-04-1313565702.30 ppb
2021-04-051810805ND
2022-04-0422300762.00 ppb
2023-04-0324744851.20 ppb