Chromium (total)
City of Opelousas 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 | 10 | 0 | ND |
| 2019 | N/A | 0 | 0 | N/A |
| 2020 | ND | 2 | 0 | ND |
| 2021 | ND | 4 | 0 | ND |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | ND | 6 | 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 |
|---|---|---|
| 2018-01-09 | AE20408 | ND |
| 2018-01-09 | AE20412 | ND |
| 2018-01-09 | AE20416 | ND |
| 2018-01-09 | AE20420 | ND |
| 2018-01-09 | AE20404 | ND |
| 2018-01-09 | AE20408 | ND |
| 2018-01-09 | AE20412 | ND |
| 2018-01-09 | AE20416 | ND |
| 2018-01-09 | AE20420 | ND |
| 2018-01-09 | AE20404 | ND |
| 2020-08-17 | B2004149-002 | ND |
| 2020-08-17 | B2004149-001 | ND |
| 2021-01-19 | B2100163-001 | ND |
| 2021-01-19 | B2100163-002 | ND |
| 2021-01-19 | B2100163-003 | ND |
| 2021-01-19 | B2100163-004 | ND |
| 2023-08-28 | B2303557-001 | ND |
| 2023-08-28 | B2303557-002 | ND |
| 2023-08-28 | B2303557-003 | ND |
| 2023-08-28 | B2303557-004 | ND |
| 2023-08-28 | B2303557-005 | ND |
| 2023-08-28 | B2303557-006 | ND |