Chromium (total)
Joshua Basin Water District
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 | 16.3 ppb | 3 | 3 | 11.0 ppb - 19.0 ppb |
| 2019 | 28.5 ppb | 2 | 2 | 24.0 ppb - 33.0 ppb |
| 2020 | 22.5 ppb | 4 | 4 | 13.0 ppb - 34.0 ppb |
| 2021 | N/A | 0 | 0 | N/A |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | 24.0 ppb | 4 | 4 | 12.0 ppb - 37.0 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 |
|---|---|---|
| 2018-05-10 | CA3610025_008_008-201805100600 | 19.0 ppb |
| 2018-11-05 | CA3610025_009_009-201811050530 | 19.0 ppb |
| 2018-11-05 | CA3610025_005_005-201811050500 | 11.0 ppb |
| 2019-02-11 | CA3610025_011_011-201902110815 | 33.0 ppb |
| 2019-02-11 | CA3610025_010_010-201902110730 | 24.0 ppb |
| 2020-11-17 | CA3610025_009_009-202011170800 | 19.0 ppb |
| 2020-11-17 | CA3610025_011_011-202011170930 | 34.0 ppb |
| 2020-11-17 | CA3610025_010_010-202011171000 | 24.0 ppb |
| 2020-11-17 | CA3610025_005_005-202011170730 | 13.0 ppb |
| 2023-11-07 | CA3610025_005_005-202311070631 | 12.0 ppb |
| 2023-11-07 | CA3610025_011_011-202311070928 | 37.0 ppb |
| 2023-11-07 | CA3610025_009_009-202311070828 | 21.0 ppb |
| 2023-11-07 | CA3610025_010_010-202311070710 | 26.0 ppb |