Chromium (total)
Hidden Valley Lake Community Services 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 | 12.5 ppb | 18 | 13 | ND - 24.0 ppb |
| 2019 | 10.9 ppb | 16 | 10 | ND - 22.0 ppb |
| 2020 | 13.7 ppb | 12 | 9 | ND - 28.0 ppb |
| 2021 | 11.2 ppb | 9 | 6 | ND - 23.0 ppb |
| 2022 | 11.1 ppb | 8 | 6 | ND - 19.0 ppb |
| 2023 | 13.0 ppb | 4 | 3 | ND - 23.0 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 |
|---|---|---|
| 2018-01-25 | CA1710015_003_003-201801250934 | ND |
| 2018-03-07 | CA1710015_003_003-201803071048 | ND |
| 2018-03-07 | CA1710015_002_002-201803071053 | 14.0 ppb |
| 2018-03-07 | CA1710015_006_006-201803071145 | 19.0 ppb |
| 2018-03-07 | CA1710015_004_004-201803071127 | 24.0 ppb |
| 2018-04-11 | CA1710015_002_002-201804111135 | 15.0 ppb |
| 2018-06-13 | CA1710015_003_003-201806131005 | ND |
| 2018-06-13 | CA1710015_004_004-201806131025 | 24.0 ppb |
| 2018-06-13 | CA1710015_006_006-201806131035 | 14.0 ppb |
| 2018-06-13 | CA1710015_002_002-201806131000 | 16.0 ppb |
| 2018-09-05 | CA1710015_002_002-201809051025 | 12.0 ppb |
| 2018-09-05 | CA1710015_004_004-201809051035 | 18.0 ppb |
| 2018-09-05 | CA1710015_003_003-201809051020 | ND |
| 2018-09-05 | CA1710015_006_006-201809051108 | 19.0 ppb |
| 2018-12-05 | CA1710015_006_006-201812051035 | 19.0 ppb |
| 2018-12-05 | CA1710015_002_002-201812051015 | 11.0 ppb |
| 2018-12-05 | CA1710015_004_004-201812051025 | 20.0 ppb |
| 2018-12-05 | CA1710015_003_003-201812051010 | ND |
| 2019-03-06 | CA1710015_006_006-201903061042 | 17.0 ppb |
| 2019-03-06 | CA1710015_003_003-201903061000 | 12.0 ppb |
| 2019-03-06 | CA1710015_004_004-201903061023 | 19.0 ppb |
| 2019-03-06 | CA1710015_002_002-201903061013 | ND |
| 2019-06-12 | CA1710015_003_003-201906121131 | ND |
| 2019-06-12 | CA1710015_002_002-201906121139 | 14.0 ppb |
| 2019-06-12 | CA1710015_006_006-201906121220 | 12.0 ppb |
| 2019-06-12 | CA1710015_004_004-201906121155 | 21.0 ppb |
| 2019-09-18 | CA1710015_003_003-201909181030 | ND |
| 2019-09-18 | CA1710015_004_004-201909181107 | 21.0 ppb |
| 2019-09-18 | CA1710015_002_002-201909181051 | ND |
| 2019-09-18 | CA1710015_006_006-201909181000 | 22.0 ppb |
| 2019-12-04 | CA1710015_006_006-201912041105 | 18.0 ppb |
| 2019-12-04 | CA1710015_003_003-201912041025 | ND |
| 2019-12-04 | CA1710015_002_002-201912041050 | ND |
| 2019-12-04 | CA1710015_004_004-201912040955 | 18.0 ppb |
| 2020-06-11 | CA1710015_003_003-202006110857 | ND |
| 2020-06-11 | CA1710015_006_006-202006110907 | 17.0 ppb |
| 2020-06-11 | CA1710015_002_002-202006110843 | 10.00 ppb |
| 2020-06-11 | CA1710015_004_004-202006110825 | 19.0 ppb |
| 2020-09-23 | CA1710015_003_003-202009230900 | ND |
| 2020-09-23 | CA1710015_004_004-202009230921 | 21.0 ppb |
| 2020-09-23 | CA1710015_002_002-202009230913 | 12.0 ppb |
| 2020-09-23 | CA1710015_006_006-202009230926 | 18.0 ppb |
| 2020-12-16 | CA1710015_002_002-202012160847 | 15.0 ppb |
| 2020-12-16 | CA1710015_003_003-202012160855 | ND |
| 2020-12-16 | CA1710015_004_004-202012160900 | 28.0 ppb |
| 2020-12-16 | CA1710015_006_006-202012160820 | 24.0 ppb |
| 2021-03-10 | CA1710015_004_004-202103100908 | 20.0 ppb |
| 2021-03-10 | CA1710015_002_002-202103100902 | 11.0 ppb |
| 2021-03-10 | CA1710015_003_003-202103100858 | ND |
| 2021-03-10 | CA1710015_006_006-202103100736 | 18.0 ppb |
| 2021-04-02 | CA1710015_003_003-202104020755 | ND |
| 2021-06-10 | CA1710015_002_002-202106100753 | 12.0 ppb |
| 2021-06-10 | CA1710015_003_003-202106100745 | ND |
| 2021-06-10 | CA1710015_004_004-202106100733 | 23.0 ppb |
| 2021-06-10 | CA1710015_006_006-202106100807 | 17.0 ppb |
| 2022-06-08 | CA1710015_002_002-202206080752 | 11.0 ppb |
| 2022-06-08 | CA1710015_003_003-202206080758 | ND |
| 2022-06-08 | CA1710015_006_006-202206080808 | 17.0 ppb |
| 2022-06-08 | CA1710015_004_004-202206080806 | 19.0 ppb |
| 2022-09-21 | CA1710015_002_002-202209210731 | 12.0 ppb |
| 2022-09-21 | CA1710015_003_003-202209210736 | ND |
| 2022-09-21 | CA1710015_004_004-202209210720 | 17.0 ppb |
| 2022-09-21 | CA1710015_006_006-202209210751 | 13.0 ppb |
| 2023-09-06 | CA1710015_006_006-202309060923 | 13.0 ppb |
| 2023-09-06 | CA1710015_002_002-202309060900 | 16.0 ppb |
| 2023-09-06 | CA1710015_004_004-202309060830 | 23.0 ppb |
| 2023-09-06 | CA1710015_003_003-202309060910 | ND |