Chromium (total)
Walnut Grove Utilities
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 | 0.500 ppb | 2 | 1 | ND - 1.000 ppb |
| 2019 | 1.88 ppb | 6 | 6 | 1.50 ppb - 2.20 ppb |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | 5.15 ppb | 2 | 2 | 4.40 ppb - 5.90 ppb |
| 2022 | 2.68 ppb | 8 | 7 | ND - 4.90 ppb |
| 2023 | 2.15 ppb | 8 | 8 | 1.40 ppb - 2.80 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 |
|---|---|---|
| 2018-08-15 | 292292-2018-DWI | 1.000 ppb |
| 2018-10-16 | 295670-2018-DW | ND |
| 2019-02-26 | 301436-2019-DW | 1.80 ppb |
| 2019-02-26 | 301437-2019-DWI | 2.10 ppb |
| 2019-03-05 | 301698-2019-DW | 1.50 ppb |
| 2019-03-05 | 301699-2019-DWI | 1.60 ppb |
| 2019-03-12 | 302100-2019-DW | 2.10 ppb |
| 2019-03-12 | 302099-2019-DW | 2.20 ppb |
| 2021-07-21 | 7380944003 | 5.90 ppb |
| 2021-09-07 | 7387721001 | 4.40 ppb |
| 2022-03-08 | 810-17505-1B | 4.90 ppb |
| 2022-03-08 | 810-17576-1B | 2.50 ppb |
| 2022-03-08 | 810-17508-1B | 3.50 ppb |
| 2022-03-09 | FWC0111A | 3.40 ppb |
| 2022-03-09 | 810-18451-1B | 3.30 ppb |
| 2022-03-09 | 810-18448-1A | 2.30 ppb |
| 2022-03-23 | 810-18980-1I | 1.50 ppb |
| 2022-05-23 | FWE0087-01 | ND |
| 2023-02-15 | FXB0429 | 1.50 ppb |
| 2023-04-04 | FXC0507-01 | 2.80 ppb |
| 2023-04-04 | FXC0516-01 | 2.50 ppb |
| 2023-04-05 | FXC0500-01 | 1.40 ppb |
| 2023-04-05 | FXC0542-01 | 2.50 ppb |
| 2023-04-05 | FXC0553-01 | 2.30 ppb |
| 2023-04-05 | FXC0559-01 | 2.60 ppb |
| 2023-07-31 | FXF0576-01 | 1.60 ppb |