Chromium (total)
Prineville, 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.
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 | N/A | 0 | 0 | N/A |
| 2019 | N/A | 0 | 0 | N/A |
| 2020 | ND | 1 | 0 | ND |
| 2021 | 1.77 ppb | 1 | 1 | 1.77 ppb |
| 2022 | 1.62 ppb | 5 | 4 | ND - 2.80 ppb |
| 2023 | 1.20 ppb | 1 | 1 | 1.20 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 |
|---|---|---|
| 2020-03-19 | X040779-I | ND |
| 2021-02-08 | X044752-I | 1.77 ppb |
| 2022-04-26 | 22-27115-I | 2.20 ppb |
| 2022-04-26 | 22-27123-I | 1.60 ppb |
| 2022-05-12 | X050385-I | ND |
| 2022-05-24 | 22-33318-I | 1.50 ppb |
| 2022-05-24 | 22-33327-I | 2.80 ppb |
| 2023-12-05 | 23_73179-I | 1.20 ppb |