Chromium (total)
Rra Preston Shores Water System
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 | ND | 1 | 0 | ND |
| 2020 | ND | 1 | 0 | ND |
| 2021 | 1.50 ppb | 1 | 1 | 1.50 ppb |
| 2022 | 2.30 ppb | 1 | 1 | 2.30 ppb |
| 2023 | ND | 1 | 0 | ND |
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 |
|---|---|---|
| 2018-06-19 | Q1824375004 | ND |
| 2019-02-25 | Q1907958002 | ND |
| 2020-03-02 | Q2007763005 | ND |
| 2021-05-19 | Q2113145003 | 1.50 ppb |
| 2022-03-02 | Q2207209002 | 2.30 ppb |
| 2023-02-22 | Q2307465003 | ND |