Chromium (total)
City of Zavalla
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | ND | 1 | 0 | ND |
| 2019 | ND | 2 | 0 | ND |
| 2020 | 1.90 ppb | 1 | 1 | 1.90 ppb |
| 2021 | 1.30 ppb | 1 | 1 | 1.30 ppb |
| 2022 | ND | 2 | 0 | ND |
| 2023 | ND | 1 | 0 | ND |
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 |
|---|---|---|
| 2018-02-12 | Q1805619006 | ND |
| 2019-02-11 | Q1906018007 | ND |
| 2019-02-11 | Q1906018008 | ND |
| 2020-01-22 | Q2002509008 | 1.90 ppb |
| 2021-01-12 | Q2100808008 | 1.30 ppb |
| 2022-01-05 | Q2200291002 | ND |
| 2022-01-05 | Q2200291004 | ND |
| 2023-01-09 | Q2300803009 | ND |