Chromium (total)
Arlington Water Department
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 | 1.67 ppb | 3 | 1 | ND - 5.00 ppb |
| 2019 | 2.00 ppb | 2 | 1 | ND - 4.00 ppb |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | 2.40 ppb | 2 | 1 | ND - 4.80 ppb |
| 2022 | 2.05 ppb | 2 | 1 | ND - 4.10 ppb |
| 2023 | 1.95 ppb | 2 | 1 | ND - 3.90 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 |
|---|---|---|
| 2018-04-17 | 5.00 ppb | |
| 2018-08-14 | ND | |
| 2018-08-14 | ND | |
| 2019-04-02 | 4.00 ppb | |
| 2019-09-11 | ND | |
| 2021-04-06 | 4095886 | 4.80 ppb |
| 2021-09-15 | 4180777 | ND |
| 2022-04-13 | 4268899 | 4.10 ppb |
| 2022-09-14 | 4359678 | ND |
| 2023-04-04 | 4439756 | 3.90 ppb |
| 2023-09-21 | 4527327 | ND |