Chromium (total)
Delft Colony Water
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 | 3.10 ppb | 2 | 2 | 2.50 ppb - 3.70 ppb |
| 2019 | N/A | 0 | 0 | N/A |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | 3.30 ppb | 1 | 1 | 3.30 ppb |
| 2022 | 2.80 ppb | 1 | 1 | 2.80 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 |
|---|---|---|
| 2018-01-23 | CA5403023_001_001-201801231100 | 2.50 ppb |
| 2018-03-27 | CA5403023_002_002-201803270945 | 3.70 ppb |
| 2021-01-18 | CA5403023_001_001-202101181130 | 3.30 ppb |
| 2022-06-23 | CA5403023_002_002-202206230900 | 2.80 ppb |