Chromium (total)
Cal Am - Dunnigan
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 | 43.5 ppb | 4 | 4 | 41.0 ppb - 47.0 ppb |
| 2019 | 36.3 ppb | 4 | 4 | 19.0 ppb - 43.0 ppb |
| 2020 | 27.0 ppb | 3 | 2 | ND - 42.0 ppb |
| 2021 | 18.3 ppb | 9 | 4 | ND - 44.0 ppb |
| 2022 | 21.9 ppb | 10 | 5 | ND - 68.0 ppb |
| 2023 | 36.1 ppb | 14 | 11 | ND - 71.0 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 |
|---|---|---|
| 2018-02-14 | CA5700712_001_001-201802140900 | 43.0 ppb |
| 2018-05-15 | CA5700712_001_001-201805150900 | 47.0 ppb |
| 2018-08-14 | CA5700712_001_001-201808141005 | 41.0 ppb |
| 2018-11-06 | CA5700712_001_001-201811061030 | 43.0 ppb |
| 2019-02-19 | CA5700712_001_001-201902191130 | 43.0 ppb |
| 2019-05-08 | CA5700712_001_001-201905080926 | 19.0 ppb |
| 2019-08-14 | CA5700712_001_001-201908141300 | 42.0 ppb |
| 2019-11-26 | CA5700712_001_001-201911261010 | 41.0 ppb |
| 2020-02-12 | CA5700712_001_001-202002121015 | 39.0 ppb |
| 2020-05-14 | CA5700712_001_001-202005140905 | 42.0 ppb |
| 2020-05-14 | CA5700712_011_011-202005141018 | ND |
| 2021-02-10 | CA5700712_011_011-202102101010 | ND |
| 2021-02-10 | CA5700712_001_001-202102100930 | 43.0 ppb |
| 2021-05-12 | CA5700712_001_001-202105120900 | 44.0 ppb |
| 2021-05-12 | CA5700712_011_011-202105121055 | ND |
| 2021-08-12 | CA5700712_011_011-202108121035 | ND |
| 2021-08-12 | CA5700712_011_011-202108121008 | ND |
| 2021-08-18 | CA5700712_001_001-202108181115 | 41.0 ppb |
| 2021-11-10 | CA5700712_001_001-202111100900 | 37.0 ppb |
| 2021-11-10 | CA5700712_011_011-202111101155 | ND |
| 2022-02-15 | CA5700712_001_001-202202151055 | 37.0 ppb |
| 2022-02-15 | CA5700712_011_011-202202151125 | ND |
| 2022-03-17 | CA5700712_001_001-202203171130 | 38.0 ppb |
| 2022-05-18 | CA5700712_011_011-202205181300 | ND |
| 2022-05-18 | CA5700712_001_001-202205181130 | 37.0 ppb |
| 2022-08-17 | CA5700712_011_011-202208170930 | ND |
| 2022-08-17 | CA5700712_001_001-202208170830 | 39.0 ppb |
| 2022-08-23 | CA5700712_050_050-202208230900 | 68.0 ppb |
| 2022-11-09 | CA5700712_001_001-202211091015 | ND |
| 2022-11-09 | CA5700712_011_011-202211091043 | ND |
| 2023-01-17 | CA5700712_050_050-202301171100 | 51.0 ppb |
| 2023-01-17 | CA5700712_050_050-202301171100 | 48.0 ppb |
| 2023-02-07 | CA5700712_001_001-202302070948 | 38.0 ppb |
| 2023-02-07 | CA5700712_050_050-202302071235 | 60.0 ppb |
| 2023-02-07 | CA5700712_011_011-202302071325 | ND |
| 2023-03-20 | CA5700712_011_011-202303201252 | ND |
| 2023-05-08 | CA5700712_011_011-202305081045 | ND |
| 2023-05-08 | CA5700712_050_050-202305081020 | 55.0 ppb |
| 2023-05-08 | CA5700712_001_001-202305080900 | 38.0 ppb |
| 2023-08-03 | CA5700712_050_050-202308031050 | 46.0 ppb |
| 2023-08-07 | CA5700712_001_001-202308070900 | 30.0 ppb |
| 2023-11-08 | CA5700712_001_001-202311080850 | 51.0 ppb |
| 2023-11-08 | CA5700712_011_011-202311081050 | 17.0 ppb |
| 2023-11-08 | CA5700712_050_050-202311080940 | 71.0 ppb |