Chromium (total)
Dighton, 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 | 3.40 ppb | 3 | 3 | 3.20 ppb - 3.70 ppb |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | 1.10 ppb | 1 | 1 | 1.10 ppb |
| 2022 | 1.73 ppb | 4 | 4 | 1.60 ppb - 1.90 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 |
|---|---|---|
| 2019-01-07 | 1101594 | 3.30 ppb |
| 2019-01-07 | 1101661 | 3.70 ppb |
| 2019-01-07 | 1101662 | 3.20 ppb |
| 2021-08-03 | 1901439 | 1.10 ppb |
| 2022-01-10 | 2128768 | 1.80 ppb |
| 2022-01-10 | 2128769 | 1.60 ppb |
| 2022-01-10 | 2128770 | 1.60 ppb |
| 2022-01-10 | 2128767 | 1.90 ppb |