Chromium (total)
Chalk Hill Special Utility District
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 | 0.600 ppb | 2 | 1 | ND - 1.20 ppb |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | ND | 1 | 0 | ND |
| 2022 | 0.750 ppb | 2 | 1 | ND - 1.50 ppb |
| 2023 | N/A | 0 | 0 | N/A |
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 |
|---|---|---|
| 2018-06-20 | Q1824487001 | ND |
| 2019-01-10 | Q1901411001 | ND |
| 2019-04-08 | Q1914000009 | 1.20 ppb |
| 2021-11-09 | Q2131359006 | ND |
| 2022-12-13 | Q2237298008 | ND |
| 2022-12-13 | Q2237298009 | 1.50 ppb |